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From: madhan@apache.org
To: commits@atlas.incubator.apache.org
Date: Fri, 30 Jun 2017 09:00:00 -0000
Message-Id: <05f7b3615eb44299b4a11f5258fbbeab@git.apache.org>
Subject: [1/5] incubator-atlas git commit: ATLAS-1880: search API with support
 for entity/tag attribute filters
archived-at: Fri, 30 Jun 2017 09:00:20 -0000

Repository: incubator-atlas
Updated Branches:
  refs/heads/master 8101883cc -> 9a4ed469c


http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/discovery/GremlinStep.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/discovery/GremlinStep.java b/repository/src/main/java/org/apache/atlas/discovery/GremlinStep.java
new file mode 100644
index 0000000..5565781
--- /dev/null
+++ b/repository/src/main/java/org/apache/atlas/discovery/GremlinStep.java
@@ -0,0 +1,388 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.atlas.discovery;
+
+import org.apache.atlas.exception.AtlasBaseException;
+import org.apache.atlas.model.discovery.SearchParameters;
+import org.apache.atlas.model.discovery.SearchParameters.FilterCriteria;
+import org.apache.atlas.model.discovery.SearchParameters.FilterCriteria.Condition;
+import org.apache.atlas.model.discovery.SearchParameters.Operator;
+import org.apache.atlas.repository.Constants;
+import org.apache.atlas.repository.graphdb.AtlasEdge;
+import org.apache.atlas.repository.graphdb.AtlasEdgeDirection;
+import org.apache.atlas.repository.graphdb.AtlasGraph;
+import org.apache.atlas.repository.graphdb.AtlasGraphQuery;
+import org.apache.atlas.repository.graphdb.AtlasIndexQuery;
+import org.apache.atlas.repository.graphdb.AtlasVertex;
+import org.apache.atlas.repository.store.graph.v1.AtlasGraphUtilsV1;
+import org.apache.atlas.type.AtlasClassificationType;
+import org.apache.atlas.type.AtlasEntityType;
+import org.apache.atlas.type.AtlasStructType;
+import org.apache.atlas.type.AtlasTypeRegistry;
+import org.apache.atlas.utils.AtlasPerfTracer;
+import org.apache.commons.collections.CollectionUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import javax.inject.Inject;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+
+import static org.apache.atlas.discovery.SearchPipeline.IndexResultType;
+import static org.apache.atlas.discovery.SearchPipeline.PipelineContext;
+import static org.apache.atlas.discovery.SearchPipeline.PipelineStep;
+import static org.apache.atlas.repository.graphdb.AtlasGraphQuery.ComparisionOperator;
+import static org.apache.atlas.repository.graphdb.AtlasGraphQuery.MatchingOperator;
+
+@Component
+public class GremlinStep implements PipelineStep {
+    private static final Logger LOG      = LoggerFactory.getLogger(GremlinStep.class);
+    private static final Logger PERF_LOG = AtlasPerfTracer.getPerfLogger("GremlinSearchStep");
+
+    private final AtlasGraph        graph;
+    private final AtlasTypeRegistry typeRegistry;
+
+    enum GremlinFilterQueryType { TAG, ENTITY }
+
+    @Inject
+    public GremlinStep(AtlasGraph graph, AtlasTypeRegistry typeRegistry) {
+        this.graph        = graph;
+        this.typeRegistry = typeRegistry;
+    }
+
+    @Override
+    public void execute(PipelineContext context) throws AtlasBaseException {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("==> GremlinStep.execute({})", context);
+        }
+
+        if (context == null) {
+            throw new AtlasBaseException("Can't start search without any context");
+        }
+
+        AtlasPerfTracer perf = null;
+
+        if (AtlasPerfTracer.isPerfTraceEnabled(PERF_LOG)) {
+            perf = AtlasPerfTracer.getPerfTracer(PERF_LOG, "GremlinSearchStep.execute(" + context +  ")");
+        }
+
+        final Iterator<AtlasVertex> result;
+
+        if (context.hasIndexResults()) {
+            // We have some results from the indexed step, let's proceed accordingly
+            if (context.getIndexResultType() == IndexResultType.TAG) {
+                // Index search was done on tag and filters
+                if (context.isTagProcessingComplete()) {
+                    LOG.debug("GremlinStep.execute(): index has completely processed tag, further TAG filtering not needed");
+
+                    Set<String> taggedVertexGUIDs = new HashSet<>();
+
+                    Iterator<AtlasIndexQuery.Result> tagVertexIterator = context.getIndexResultsIterator();
+
+                    while (tagVertexIterator.hasNext()) {
+                        // Find out which Vertex has this outgoing edge
+                        AtlasVertex         vertex = tagVertexIterator.next().getVertex();
+                        Iterable<AtlasEdge> edges  = vertex.getEdges(AtlasEdgeDirection.IN);
+
+                        for (AtlasEdge edge : edges) {
+                            String guid = AtlasGraphUtilsV1.getIdFromVertex(edge.getOutVertex());
+
+                            taggedVertexGUIDs.add(guid);
+                        }
+                    }
+
+                    // No entities are tagged  (actually this check is already done)
+                    if (!taggedVertexGUIDs.isEmpty()) {
+                        result = processEntity(taggedVertexGUIDs, context);
+                    } else {
+                        result = null;
+                    }
+                } else {
+                    result = processTagAndEntity(Collections.<String>emptySet(), context);
+                }
+            } else if (context.getIndexResultType() == IndexResultType.TEXT) {
+                // Index step processed full-text;
+                Set<String> entityIDs = getVertexIDs(context.getIndexResultsIterator());
+
+                result = processTagAndEntity(entityIDs, context);
+            } else if (context.getIndexResultType() == IndexResultType.ENTITY) {
+                // Index step processed entity and it's filters; tag filter wouldn't be set
+                Set<String> entityIDs = getVertexIDs(context.getIndexResultsIterator());
+
+                result = processEntity(entityIDs, context);
+            } else {
+                result = null;
+            }
+        } else {
+            // No index results, need full processing in Gremlin
+            if (context.getClassificationType() != null) {
+                // Process tag and filters first, then entity filters
+                result = processTagAndEntity(Collections.<String>emptySet(), context);
+            } else {
+                result = processEntity(Collections.<String>emptySet(), context);
+            }
+        }
+
+        context.setGremlinResultIterator(result);
+
+        AtlasPerfTracer.log(perf);
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("<== GremlinStep.execute({})", context);
+        }
+    }
+
+    private Iterator<AtlasVertex> processEntity(Set<String> entityGUIDs, PipelineContext context) {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("==> GremlinStep.processEntity(entityGUIDs={})", entityGUIDs);
+        }
+
+        final Iterator<AtlasVertex> ret;
+
+        SearchParameters searchParameters = context.getSearchParameters();
+        AtlasEntityType  entityType       = context.getEntityType();
+
+        if (entityType != null) {
+            AtlasGraphQuery entityFilterQuery = context.getGraphQuery("ENTITY_FILTER");
+
+            if (entityFilterQuery == null) {
+                entityFilterQuery = graph.query().in(Constants.TYPE_NAME_PROPERTY_KEY, entityType.getTypeAndAllSubTypes());
+
+                if (searchParameters.getEntityFilters() != null) {
+                    toGremlinFilterQuery(GremlinFilterQueryType.ENTITY, entityType, searchParameters.getEntityFilters(), entityFilterQuery, context);
+                }
+
+                if (searchParameters.getExcludeDeletedEntities()) {
+                    entityFilterQuery.has(Constants.STATE_PROPERTY_KEY, "ACTIVE");
+                }
+
+                context.cacheGraphQuery("ENTITY_FILTER", entityFilterQuery);
+            }
+
+            // Now get all vertices
+            if (CollectionUtils.isEmpty(entityGUIDs)) {
+                ret = entityFilterQuery.vertices(context.getCurrentOffset(), context.getMaxLimit()).iterator();
+            } else {
+                AtlasGraphQuery guidQuery = graph.query().in(Constants.GUID_PROPERTY_KEY, entityGUIDs);
+
+                if (entityFilterQuery != null) {
+                    guidQuery.addConditionsFrom(entityFilterQuery);
+                } else if (searchParameters.getExcludeDeletedEntities()) {
+                    guidQuery.has(Constants.STATE_PROPERTY_KEY, "ACTIVE");
+                }
+
+                ret = guidQuery.vertices(context.getMaxLimit()).iterator();
+            }
+        } else if (CollectionUtils.isNotEmpty(entityGUIDs)) {
+            AtlasGraphQuery guidQuery = graph.query().in(Constants.GUID_PROPERTY_KEY, entityGUIDs);
+
+            if (searchParameters.getExcludeDeletedEntities()) {
+                guidQuery.has(Constants.STATE_PROPERTY_KEY, "ACTIVE");
+            }
+
+            Iterable<AtlasVertex> vertices = guidQuery.vertices(context.getMaxLimit());
+
+            ret = vertices.iterator();
+        } else {
+            ret = null;
+        }
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("<== GremlinStep.processEntity(entityGUIDs={})", entityGUIDs);
+        }
+
+        return ret;
+    }
+
+    private Iterator<AtlasVertex> processTagAndEntity(Set<String> entityGUIDs, PipelineContext context) {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("==> GremlinStep.processTagAndEntity(entityGUIDs={})", entityGUIDs);
+        }
+
+        final Iterator<AtlasVertex> ret;
+
+        AtlasClassificationType classificationType = context.getClassificationType();
+
+        if (classificationType != null) {
+            AtlasGraphQuery  tagVertexQuery = context.getGraphQuery("TAG_VERTEX");
+
+            if (tagVertexQuery == null) {
+                tagVertexQuery = graph.query().in(Constants.TYPE_NAME_PROPERTY_KEY, classificationType.getTypeAndAllSubTypes());
+
+                SearchParameters searchParameters = context.getSearchParameters();
+
+                // Do tag filtering first as it'll return a smaller subset of vertices
+                if (searchParameters.getTagFilters() != null) {
+                    toGremlinFilterQuery(GremlinFilterQueryType.TAG, classificationType, searchParameters.getTagFilters(), tagVertexQuery, context);
+                }
+
+                context.cacheGraphQuery("TAG_VERTEX", tagVertexQuery);
+            }
+
+            if (tagVertexQuery != null) {
+                Set<String> taggedVertexGuids = new HashSet<>();
+                // Now get all vertices after adjusting offset for each iteration
+                LOG.debug("Firing TAG query");
+
+                Iterator<AtlasVertex> tagVertexIterator = tagVertexQuery.vertices(context.getCurrentOffset(), context.getMaxLimit()).iterator();
+
+                while (tagVertexIterator.hasNext()) {
+                    // Find out which Vertex has this outgoing edge
+                    Iterable<AtlasEdge> edges = tagVertexIterator.next().getEdges(AtlasEdgeDirection.IN);
+                    for (AtlasEdge edge : edges) {
+                        String guid = AtlasGraphUtilsV1.getIdFromVertex(edge.getOutVertex());
+                        taggedVertexGuids.add(guid);
+                    }
+                }
+
+                entityGUIDs = taggedVertexGuids;
+            }
+        }
+
+        if (!entityGUIDs.isEmpty()) {
+            ret = processEntity(entityGUIDs, context);
+        } else {
+            ret = null;
+        }
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("<== GremlinStep.processTagAndEntity(entityGUIDs={})", entityGUIDs);
+        }
+
+        return ret;
+    }
+
+    private Set<String> getVertexIDs(Iterator<AtlasIndexQuery.Result> idxResultsIterator) {
+        Set<String> guids = new HashSet<>();
+        while (idxResultsIterator.hasNext()) {
+            AtlasVertex vertex = idxResultsIterator.next().getVertex();
+            String guid = AtlasGraphUtilsV1.getIdFromVertex(vertex);
+            guids.add(guid);
+        }
+        return guids;
+    }
+
+    private Set<String> getVertexIDs(Iterable<AtlasVertex> vertices) {
+        Set<String> guids = new HashSet<>();
+        for (AtlasVertex vertex : vertices) {
+            String guid = AtlasGraphUtilsV1.getIdFromVertex(vertex);
+            guids.add(guid);
+        }
+        return guids;
+    }
+
+    private AtlasGraphQuery toGremlinFilterQuery(GremlinFilterQueryType queryType, AtlasStructType type, FilterCriteria criteria,
+                                                 AtlasGraphQuery query, PipelineContext context) {
+        if (criteria.getCondition() != null) {
+            if (criteria.getCondition() == Condition.AND) {
+                for (FilterCriteria filterCriteria : criteria.getCriterion()) {
+                    AtlasGraphQuery nestedQuery = toGremlinFilterQuery(queryType, type, filterCriteria, graph.query(), context);
+                    query.addConditionsFrom(nestedQuery);
+                }
+            } else {
+                List<AtlasGraphQuery> orConditions = new LinkedList<>();
+
+                for (FilterCriteria filterCriteria : criteria.getCriterion()) {
+                    AtlasGraphQuery nestedQuery = toGremlinFilterQuery(queryType, type, filterCriteria, graph.query(), context);
+                    // FIXME: Something might not be right here as the queries are getting overwritten sometimes
+                    orConditions.add(graph.query().createChildQuery().addConditionsFrom(nestedQuery));
+                }
+
+                if (!orConditions.isEmpty()) {
+                    query.or(orConditions);
+                }
+            }
+        } else {
+            String   attrName  = criteria.getAttributeName();
+            String   attrValue = criteria.getAttributeValue();
+            Operator operator  = criteria.getOperator();
+
+            try {
+                // If attribute belongs to supertype then adjust the name accordingly
+                final String  qualifiedAttributeName;
+                final boolean attrProcessed;
+
+                if (queryType == GremlinFilterQueryType.TAG) {
+                    qualifiedAttributeName = type.getQualifiedAttributeName(attrName);
+                    attrProcessed          = context.hasProcessedTagAttribute(qualifiedAttributeName);
+                } else {
+                    qualifiedAttributeName = type.getQualifiedAttributeName(attrName);
+                    attrProcessed          = context.hasProcessedEntityAttribute(qualifiedAttributeName);
+                }
+
+                // Check if the qualifiedAttribute has been processed
+                if (!attrProcessed) {
+                    switch (operator) {
+                        case LT:
+                            query.has(qualifiedAttributeName, ComparisionOperator.LESS_THAN, attrValue);
+                            break;
+                        case LTE:
+                            query.has(qualifiedAttributeName, ComparisionOperator.LESS_THAN_EQUAL, attrValue);
+                            break;
+                        case GT:
+                            query.has(qualifiedAttributeName, ComparisionOperator.GREATER_THAN, attrValue);
+                            break;
+                        case GTE:
+                            query.has(qualifiedAttributeName, ComparisionOperator.GREATER_THAN_EQUAL, attrValue);
+                            break;
+                        case EQ:
+                            query.has(qualifiedAttributeName, ComparisionOperator.EQUAL, attrValue);
+                            break;
+                        case NEQ:
+                            query.has(qualifiedAttributeName, ComparisionOperator.NOT_EQUAL, attrValue);
+                            break;
+                        case LIKE:
+                            // TODO: Maybe we need to validate pattern
+                            query.has(qualifiedAttributeName, MatchingOperator.REGEX, getLikeRegex(attrValue));
+                            break;
+                        case CONTAINS:
+                            query.has(qualifiedAttributeName, MatchingOperator.REGEX, getContainsRegex(attrValue));
+                            break;
+                        case STARTS_WITH:
+                            query.has(qualifiedAttributeName, MatchingOperator.PREFIX, attrValue);
+                            break;
+                        case ENDS_WITH:
+                            query.has(qualifiedAttributeName, MatchingOperator.REGEX, getSuffixRegex(attrValue));
+                        case IN:
+                            LOG.warn("{}: unsupported operator. Ignored", operator);
+                            break;
+                    }
+                }
+            } catch (AtlasBaseException e) {
+                LOG.error("toGremlinFilterQuery(): failed for attrName=" + attrName + "; operator=" + operator + "; attrValue=" + attrValue, e);
+            }
+        }
+
+        return query;
+    }
+
+    private String getContainsRegex(String attributeValue) {
+        return ".*" + attributeValue + ".*";
+    }
+
+    private String getSuffixRegex(String attributeValue) {
+        return ".*" + attributeValue;
+    }
+
+    private String getLikeRegex(String attributeValue) { return ".*" + attributeValue + ".*"; }
+}

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/discovery/SearchPipeline.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/discovery/SearchPipeline.java b/repository/src/main/java/org/apache/atlas/discovery/SearchPipeline.java
new file mode 100644
index 0000000..0f91b2d
--- /dev/null
+++ b/repository/src/main/java/org/apache/atlas/discovery/SearchPipeline.java
@@ -0,0 +1,611 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.atlas.discovery;
+
+import org.apache.atlas.exception.AtlasBaseException;
+import org.apache.atlas.model.discovery.SearchParameters;
+import org.apache.atlas.model.discovery.SearchParameters.FilterCriteria;
+import org.apache.atlas.model.discovery.SearchParameters.FilterCriteria.Condition;
+import org.apache.atlas.repository.Constants;
+import org.apache.atlas.repository.graph.GraphBackedSearchIndexer;
+import org.apache.atlas.repository.graphdb.*;
+import org.apache.atlas.type.AtlasClassificationType;
+import org.apache.atlas.type.AtlasEntityType;
+import org.apache.atlas.type.AtlasStructType;
+import org.apache.atlas.type.AtlasTypeRegistry;
+import org.apache.atlas.util.SearchTracker;
+import org.apache.atlas.utils.AtlasPerfTracer;
+import org.apache.commons.collections.CollectionUtils;
+import org.apache.commons.configuration.Configuration;
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.lang.builder.ToStringBuilder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import javax.inject.Inject;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+@Component
+public class SearchPipeline {
+    private static final Logger LOG      = LoggerFactory.getLogger(SearchPipeline.class);
+    private static final Logger PERF_LOG = AtlasPerfTracer.getPerfLogger("SearchPipeline");
+
+    enum ExecutionMode { SOLR, GREMLIN, MIXED }
+
+    enum IndexResultType { TAG, ENTITY, TEXT }
+
+    private final SolrStep                 solrStep;
+    private final GremlinStep              gremlinStep;
+    private final SearchTracker            searchTracker;
+    private final AtlasTypeRegistry        typeRegistry;
+    private final Configuration            atlasConfiguration;
+    private final GraphBackedSearchIndexer indexer;
+
+    @Inject
+    public SearchPipeline(SolrStep solrStep, GremlinStep gremlinStep, SearchTracker searchTracker, AtlasTypeRegistry typeRegistry, Configuration atlasConfiguration, GraphBackedSearchIndexer indexer) {
+        this.solrStep           = solrStep;
+        this.gremlinStep        = gremlinStep;
+        this.searchTracker      = searchTracker;
+        this.typeRegistry       = typeRegistry;
+        this.atlasConfiguration = atlasConfiguration;
+        this.indexer            = indexer;
+    }
+
+    public List<AtlasVertex> run(SearchParameters searchParameters) throws AtlasBaseException {
+        final List<AtlasVertex> ret;
+
+        AtlasPerfTracer perf = null;
+
+        if (AtlasPerfTracer.isPerfTraceEnabled(PERF_LOG)) {
+            perf = AtlasPerfTracer.getPerfTracer(PERF_LOG, "SearchPipeline.run("+ searchParameters +")");
+        }
+
+        AtlasEntityType         entityType = typeRegistry.getEntityTypeByName(searchParameters.getTypeName());
+        AtlasClassificationType classiType = typeRegistry.getClassificationTypeByName(searchParameters.getClassification());
+        PipelineContext         context    = new PipelineContext(searchParameters, entityType, classiType, indexer.getVertexIndexKeys());
+        String                  searchId   = searchTracker.add(context); // For future cancellation
+
+        try {
+            ExecutionMode mode = determineExecutionMode(context);
+
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Execution mode {}", mode);
+            }
+
+            switch (mode) {
+                case SOLR:
+                    ret = runOnlySolr(context);
+                    break;
+
+                case GREMLIN:
+                    ret = runOnlyGremlin(context);
+                    break;
+
+                case MIXED:
+                    ret = runMixed(context);
+                    break;
+
+                default:
+                    ret = Collections.emptyList();
+            }
+        } finally {
+            searchTracker.remove(searchId);
+
+            AtlasPerfTracer.log(perf);
+        }
+
+        return ret;
+    }
+
+    private List<AtlasVertex> runOnlySolr(PipelineContext context) throws AtlasBaseException {
+        // Only when there's no tag and query
+        List<AtlasVertex> results = new ArrayList<>();
+
+        while (results.size() < context.getSearchParameters().getLimit()) {
+            if (context.getForceTerminate()) {
+                LOG.debug("search has been terminated");
+
+                break;
+            }
+
+            // Execute solr search only
+            solrStep.execute(context);
+
+            List<AtlasVertex> stepResults = getIndexResults(context);
+
+            context.incrementSearchRound();
+
+            addToResult(results, stepResults, context.getSearchParameters().getLimit());
+
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Pipeline iteration {}: stepResults={}; totalResult={}", context.getIterationCount(), stepResults.size(), results.size());
+            }
+
+            if (CollectionUtils.isEmpty(stepResults)) {
+                // If no result is found any subsequent iteration then just stop querying the index
+                break;
+            }
+        }
+
+        if (context.getIndexResultType() == IndexResultType.TAG) {
+            List<AtlasVertex> entityVertices = new ArrayList<>(results.size());
+
+            for (AtlasVertex tagVertex : results) {
+                Iterable<AtlasEdge> edges = tagVertex.getEdges(AtlasEdgeDirection.IN);
+
+                for (AtlasEdge edge : edges) {
+                    AtlasVertex entityVertex = edge.getOutVertex();
+
+                    entityVertices.add(entityVertex);
+                }
+            }
+
+            results = entityVertices;
+        }
+
+        return results;
+    }
+
+    private List<AtlasVertex> runOnlyGremlin(PipelineContext context) throws AtlasBaseException {
+        List<AtlasVertex> results = new ArrayList<>();
+
+        while (results.size() < context.getSearchParameters().getLimit()) {
+            if (context.getForceTerminate()) {
+                LOG.debug("search has been terminated");
+
+                break;
+            }
+
+            gremlinStep.execute(context);
+
+            List<AtlasVertex> stepResults = getGremlinResults(context);
+
+            context.incrementSearchRound();
+
+            addToResult(results, stepResults, context.getSearchParameters().getLimit());
+
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Pipeline iteration {}: stepResults={}; totalResult={}", context.getIterationCount(), stepResults.size(), results.size());
+            }
+
+            if (CollectionUtils.isEmpty(stepResults)) {
+                // If no result is found any subsequent iteration then just stop querying the index
+                break;
+            }
+        }
+
+        return results;
+    }
+
+    /*
+        1. Index processes few attributes and then gremlin processes rest
+            1.1 Iterate for gremlin till the index results are non null
+        2. Index processes all attributes, gremlin has nothing to do
+
+        Sometimes the result set might be less than the max limit and we need to iterate until the result set is full
+        or the iteration doesn't return any results
+
+     */
+    private List<AtlasVertex> runMixed(PipelineContext context) throws AtlasBaseException {
+        List<AtlasVertex> results = new ArrayList<>();
+
+        while (results.size() < context.getSearchParameters().getLimit()) {
+            if (context.getForceTerminate()) {
+                LOG.debug("search has been terminated");
+
+                break;
+            }
+
+            // Execute Solr search and then pass it to the Gremlin step (if needed)
+            solrStep.execute(context);
+
+            if (!context.hasIndexResults()) {
+                if (LOG.isDebugEnabled()) {
+                    LOG.debug("No index results in iteration {}", context.getIterationCount());
+                }
+
+                // If no result is found any subsequent iteration then just stop querying the index
+                break;
+            }
+
+            // Attributes partially processed by Solr, use gremlin to process remaining attribute(s)
+            gremlinStep.execute(context);
+
+            context.incrementSearchRound();
+
+            List<AtlasVertex> stepResults = getGremlinResults(context);
+
+            addToResult(results, stepResults, context.getSearchParameters().getLimit());
+
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Pipeline iteration {}: stepResults={}; totalResult={}", context.getIterationCount(), stepResults.size(), results.size());
+            }
+        }
+
+        return results;
+    }
+
+    private void addToResult(List<AtlasVertex> result, List<AtlasVertex> stepResult, int maxLimit) {
+        if (result != null && stepResult != null && result.size() < maxLimit) {
+            for (AtlasVertex vertex : stepResult) {
+                result.add(vertex);
+
+                if (result.size() >= maxLimit) {
+                    break;
+                }
+            }
+        }
+    }
+
+    private List<AtlasVertex> getIndexResults(PipelineContext pipelineContext) {
+        List<AtlasVertex> ret = new ArrayList<>();
+
+        if (pipelineContext.hasIndexResults()) {
+            Iterator<AtlasIndexQuery.Result> iter = pipelineContext.getIndexResultsIterator();
+
+            while(iter.hasNext()) {
+                ret.add(iter.next().getVertex());
+            }
+        }
+
+        return ret;
+    }
+
+    private List<AtlasVertex> getGremlinResults(PipelineContext pipelineContext) {
+        List<AtlasVertex> ret = new ArrayList<>();
+
+        if (pipelineContext.hasGremlinResults()) {
+            Iterator<AtlasVertex> iter = pipelineContext.getGremlinResultIterator();
+
+            while (iter.hasNext()) {
+                ret.add(iter.next());
+            }
+        }
+
+        return ret;
+    }
+
+    private ExecutionMode determineExecutionMode(PipelineContext context) {
+        SearchParameters        searchParameters   = context.getSearchParameters();
+        AtlasClassificationType classificationType = context.getClassificationType();
+        AtlasEntityType         entityType         = context.getEntityType();
+        int                     solrCount          = 0;
+        int                     gremlinCount       = 0;
+
+        if (StringUtils.isNotEmpty(searchParameters.getQuery())) {
+            solrCount++;
+
+            // __state index only exists in vertex_index
+            if (searchParameters.getExcludeDeletedEntities()) {
+                gremlinCount++;
+            }
+        }
+
+        if (classificationType != null) {
+            Set<String> typeAndAllSubTypes = classificationType.getTypeAndAllSubTypes();
+
+            if (typeAndAllSubTypes.size() > atlasConfiguration.getInt(Constants.INDEX_SEARCH_MAX_TAGS_COUNT, 10)) {
+                if (LOG.isDebugEnabled()) {
+                    LOG.debug("Classification type {} has too many subTypes ({}) to use in Solr search. Gremlin will be used to execute the search",
+                              classificationType.getTypeName(), typeAndAllSubTypes.size());
+                }
+
+                gremlinCount++;
+            } else {
+                if (hasNonIndexedAttrViolation(classificationType, context.getIndexedKeys(), searchParameters.getTagFilters())) {
+                    if (LOG.isDebugEnabled()) {
+                        LOG.debug("Tag filters not suitable for Solr search. Gremlin will be used to execute the search");
+                    }
+
+                    gremlinCount++;
+                } else {
+                    solrCount++;
+
+                    // __state index only exist in vertex_index
+                    if (searchParameters.getExcludeDeletedEntities()) {
+                        gremlinCount++;
+                    }
+                }
+            }
+        }
+
+        if (entityType != null) {
+            Set<String> typeAndAllSubTypes = entityType.getTypeAndAllSubTypes();
+
+            if (typeAndAllSubTypes.size() > atlasConfiguration.getInt(Constants.INDEX_SEARCH_MAX_TYPES_COUNT, 10)) {
+                if (LOG.isDebugEnabled()) {
+                    LOG.debug("Entity type {} has too many subTypes ({}) to use in Solr search. Gremlin will be used to execute the search",
+                              entityType.getTypeName(), typeAndAllSubTypes.size());
+                }
+
+                gremlinCount++;
+            } else {
+                if (hasNonIndexedAttrViolation(entityType, context.getIndexedKeys(), searchParameters.getEntityFilters())) {
+                    if (LOG.isDebugEnabled()) {
+                        LOG.debug("Entity filters not suitable for Solr search. Gremlin will be used to execute the search");
+                    }
+
+                    gremlinCount++;
+                } else {
+                    solrCount++;
+                }
+            }
+        }
+
+        ExecutionMode mode = ExecutionMode.MIXED;
+
+        if (solrCount == 1 && gremlinCount == 0) {
+            mode = ExecutionMode.SOLR;
+        } else if (gremlinCount == 1 && solrCount == 0) {
+            mode = ExecutionMode.GREMLIN;
+        }
+
+        return mode;
+    }
+
+    // If Index can't process all attributes and any of the non-indexed attribute is present in OR nested within AND
+    // then the only way is Gremlin
+    // A violation (here) is defined as presence of non-indexed attribute within any OR clause nested under an AND clause
+    // the reason being that the index would not be able to process the nested OR attribute which might result in
+    // exclusion of valid result (vertex)
+    private boolean hasNonIndexedAttrViolation(AtlasStructType structType, Set<String> indexKeys, FilterCriteria filterCriteria) {
+        return hasNonIndexedAttrViolation(structType, indexKeys, filterCriteria, false);
+    }
+
+    private boolean hasNonIndexedAttrViolation(AtlasStructType structType, Set<String> indexKeys, FilterCriteria filterCriteria, boolean enclosedInOrCondition) {
+        if (filterCriteria == null) {
+            return false;
+        }
+
+        boolean              ret             = false;
+        Condition            filterCondition = filterCriteria.getCondition();
+        List<FilterCriteria> criterion       = filterCriteria.getCriterion();
+
+        if (filterCondition != null && CollectionUtils.isNotEmpty(criterion)) {
+            if (!enclosedInOrCondition) {
+                enclosedInOrCondition = filterCondition == Condition.OR;
+            }
+
+            // If we have nested criterion let's find any nested ORs with non-indexed attr
+            for (FilterCriteria criteria : criterion) {
+                ret |= hasNonIndexedAttrViolation(structType, indexKeys, criteria, enclosedInOrCondition);
+
+                if (ret) {
+                    break;
+                }
+            }
+        } else if (StringUtils.isNotEmpty(filterCriteria.getAttributeName())) {
+            // If attribute qualified name doesn't exist in the vertex index we potentially might have a problem
+            try {
+                String qualifiedAttributeName = structType.getQualifiedAttributeName(filterCriteria.getAttributeName());
+
+                ret = CollectionUtils.isEmpty(indexKeys) || !indexKeys.contains(qualifiedAttributeName);
+
+                if (ret) {
+                    LOG.warn("search includes non-indexed attribute '{}'; might cause poor performance", qualifiedAttributeName);
+                }
+            } catch (AtlasBaseException e) {
+                LOG.warn(e.getMessage());
+
+                ret = true;
+            }
+        }
+
+        // return ret && enclosedInOrCondition;
+
+        return ret;
+    }
+
+    public interface PipelineStep {
+        void execute(PipelineContext context) throws AtlasBaseException;
+    }
+
+    public static class PipelineContext {
+        // TODO: See if anything can be cached in the context
+
+        private final SearchParameters        searchParameters;
+        private final AtlasEntityType         entityType;
+        private final AtlasClassificationType classificationType;
+        private final Set<String>             indexedKeys;
+
+        private int     iterationCount;
+        private boolean forceTerminate;
+        private int     currentOffset;
+        private int     maxLimit;
+
+        // Continuous processing stuff
+        private Set<String> tagSearchAttributes       = new HashSet<>();
+        private Set<String> entitySearchAttributes    = new HashSet<>();
+        private Set<String> tagAttrProcessedBySolr    = new HashSet<>();
+        private Set<String> entityAttrProcessedBySolr = new HashSet<>();
+
+        // Results related stuff
+        private IndexResultType                  indexResultType;
+        private Iterator<AtlasIndexQuery.Result> indexResultsIterator;
+        private Iterator<AtlasVertex>            gremlinResultIterator;
+
+        private Map<String, AtlasIndexQuery> cachedIndexQueries = new HashMap<>();
+        private Map<String, AtlasGraphQuery> cachedGraphQueries = new HashMap<>();
+
+        public PipelineContext(SearchParameters searchParameters, AtlasEntityType entityType, AtlasClassificationType classificationType, Set<String> indexedKeys) {
+            this.searchParameters   = searchParameters;
+            this.entityType         = entityType;
+            this.classificationType = classificationType;
+            this.indexedKeys        = indexedKeys;
+
+            currentOffset = searchParameters.getOffset();
+            maxLimit      = searchParameters.getLimit();
+        }
+
+        public SearchParameters getSearchParameters() {
+            return searchParameters;
+        }
+
+        public AtlasEntityType getEntityType() {
+            return entityType;
+        }
+
+        public AtlasClassificationType getClassificationType() {
+            return classificationType;
+        }
+
+        public Set<String> getIndexedKeys() { return indexedKeys; }
+
+        public int getIterationCount() {
+            return iterationCount;
+        }
+
+        public boolean getForceTerminate() {
+            return forceTerminate;
+        }
+
+        public void setForceTerminate(boolean forceTerminate) {
+            this.forceTerminate = forceTerminate;
+        }
+
+        public boolean hasProcessedTagAttribute(String attributeName) {
+            return tagAttrProcessedBySolr.contains(attributeName);
+        }
+
+        public boolean hasProcessedEntityAttribute(String attributeName) {
+            return entityAttrProcessedBySolr.contains(attributeName);
+        }
+
+        public Iterator<AtlasIndexQuery.Result> getIndexResultsIterator() {
+            return indexResultsIterator;
+        }
+
+        public void setIndexResultsIterator(Iterator<AtlasIndexQuery.Result> indexResultsIterator) {
+            this.indexResultsIterator = indexResultsIterator;
+        }
+
+        public Iterator<AtlasVertex> getGremlinResultIterator() {
+            return gremlinResultIterator;
+        }
+
+        public void setGremlinResultIterator(Iterator<AtlasVertex> gremlinResultIterator) {
+            this.gremlinResultIterator = gremlinResultIterator;
+        }
+
+        public boolean hasIndexResults() {
+            return null != indexResultsIterator && indexResultsIterator.hasNext();
+        }
+
+        public boolean hasGremlinResults() {
+            return null != gremlinResultIterator && gremlinResultIterator.hasNext();
+        }
+
+
+        public boolean isTagProcessingComplete() {
+            return CollectionUtils.isEmpty(tagSearchAttributes) ||
+                    CollectionUtils.isEqualCollection(tagSearchAttributes, tagAttrProcessedBySolr);
+        }
+
+        public boolean isEntityProcessingComplete() {
+            return CollectionUtils.isEmpty(entitySearchAttributes) ||
+                    CollectionUtils.isEqualCollection(entitySearchAttributes, entityAttrProcessedBySolr);
+        }
+
+        public boolean isProcessingComplete() {
+            return isTagProcessingComplete() && isEntityProcessingComplete();
+        }
+
+        public void incrementOffset(int increment) {
+            currentOffset += increment;
+        }
+
+        public void incrementSearchRound() {
+            iterationCount ++;
+            incrementOffset(searchParameters.getLimit());
+        }
+
+        public int getCurrentOffset() {
+            return currentOffset;
+        }
+
+        public boolean addTagSearchAttribute(String attribute) {
+            return tagSearchAttributes.add(attribute);
+        }
+
+        public boolean addProcessedTagAttribute(String attribute) {
+            return tagAttrProcessedBySolr.add(attribute);
+        }
+
+        public boolean addEntitySearchAttribute(String attribute) {
+            return tagSearchAttributes.add(attribute);
+        }
+
+        public boolean addProcessedEntityAttribute(String attribute) {
+            return entityAttrProcessedBySolr.add(attribute);
+        }
+
+        public void cacheGraphQuery(String name, AtlasGraphQuery graphQuery) {
+            cachedGraphQueries.put(name, graphQuery);
+        }
+
+        public void cacheIndexQuery(String name, AtlasIndexQuery indexQuery) {
+            cachedIndexQueries.put(name, indexQuery);
+        }
+
+        public AtlasIndexQuery getIndexQuery(String name){
+            return cachedIndexQueries.get(name);
+        }
+
+        public AtlasGraphQuery getGraphQuery(String name) {
+            return cachedGraphQueries.get(name);
+        }
+
+        public IndexResultType getIndexResultType() {
+            return indexResultType;
+        }
+
+        public void setIndexResultType(IndexResultType indexResultType) {
+            this.indexResultType = indexResultType;
+        }
+
+        public int getMaxLimit() {
+            return maxLimit;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this)
+                    .append("iterationCount", iterationCount)
+                    .append("forceTerminate", forceTerminate)
+                    .append("currentOffset", currentOffset)
+                    .append("maxLimit", maxLimit)
+                    .append("searchParameters", searchParameters)
+                    .append("tagSearchAttributes", tagSearchAttributes)
+                    .append("entitySearchAttributes", entitySearchAttributes)
+                    .append("tagAttrProcessedBySolr", tagAttrProcessedBySolr)
+                    .append("entityAttrProcessedBySolr", entityAttrProcessedBySolr)
+                    .append("indexResultType", indexResultType)
+                    .append("cachedIndexQueries", cachedIndexQueries)
+                    .append("cachedGraphQueries", cachedGraphQueries)
+                    .toString();
+        }
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/discovery/SolrStep.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/discovery/SolrStep.java b/repository/src/main/java/org/apache/atlas/discovery/SolrStep.java
new file mode 100644
index 0000000..6a5dd5a
--- /dev/null
+++ b/repository/src/main/java/org/apache/atlas/discovery/SolrStep.java
@@ -0,0 +1,288 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.atlas.discovery;
+
+import org.apache.atlas.discovery.SearchPipeline.IndexResultType;
+import org.apache.atlas.discovery.SearchPipeline.PipelineContext;
+import org.apache.atlas.discovery.SearchPipeline.PipelineStep;
+import org.apache.atlas.exception.AtlasBaseException;
+import org.apache.atlas.model.discovery.SearchParameters;
+import org.apache.atlas.model.discovery.SearchParameters.Operator;
+import org.apache.atlas.repository.Constants;
+import org.apache.atlas.repository.graphdb.AtlasGraph;
+import org.apache.atlas.repository.graphdb.AtlasIndexQuery;
+import org.apache.atlas.type.*;
+import org.apache.commons.collections.CollectionUtils;
+import org.apache.commons.lang.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import javax.inject.Inject;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+import static org.apache.atlas.model.discovery.SearchParameters.*;
+
+@Component
+public class SolrStep implements PipelineStep {
+    private static final Logger LOG = LoggerFactory.getLogger(SolrStep.class);
+
+    private static final Pattern STRAY_AND_PATTERN     = Pattern.compile("(AND\\s+)+\\)");
+    private static final Pattern STRAY_OR_PATTERN      = Pattern.compile("(OR\\s+)+\\)");
+    private static final Pattern STRAY_ELIPSIS_PATTERN = Pattern.compile("(\\(\\s*)\\)");
+    private static final String  AND_STR         = " AND ";
+    private static final String  EMPTY_STRING    = "";
+    private static final String  SPACE_STRING    = " ";
+    private static final String  BRACE_OPEN_STR  = "( ";
+    private static final String  BRACE_CLOSE_STR = " )";
+
+    private static final Map<Operator, String> operatorMap = new HashMap<>();
+
+    static
+    {
+        operatorMap.put(Operator.LT,"v.\"%s\": [* TO %s}");
+        operatorMap.put(Operator.GT,"v.\"%s\": {%s TO *]");
+        operatorMap.put(Operator.LTE,"v.\"%s\": [* TO %s]");
+        operatorMap.put(Operator.GTE,"v.\"%s\": [%s TO *]");
+        operatorMap.put(Operator.EQ,"v.\"%s\": %s");
+        operatorMap.put(Operator.NEQ,"v.\"%s\": (NOT %s)");
+        operatorMap.put(Operator.IN, "v.\"%s\": (%s)");
+        operatorMap.put(Operator.LIKE, "v.\"%s\": (%s)");
+        operatorMap.put(Operator.STARTS_WITH, "v.\"%s\": (%s*)");
+        operatorMap.put(Operator.ENDS_WITH, "v.\"%s\": (*%s)");
+        operatorMap.put(Operator.CONTAINS, "v.\"%s\": (*%s*)");
+    }
+
+    private final AtlasGraph graph;
+
+    @Inject
+    public SolrStep(AtlasGraph graph) {
+        this.graph = graph;
+    }
+
+    @Override
+    public void execute(PipelineContext context) throws AtlasBaseException {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("==> SolrStep.execute({})", context);
+        }
+
+        if (context == null) {
+            throw new AtlasBaseException("Can't start search without any context");
+        }
+
+        SearchParameters searchParameters = context.getSearchParameters();
+
+        final Iterator<AtlasIndexQuery.Result> result;
+
+        if (StringUtils.isNotEmpty(searchParameters.getQuery())) {
+            result = executeAgainstFulltextIndex(context);
+        } else {
+            result = executeAgainstVertexIndex(context);
+        }
+
+        context.setIndexResultsIterator(result);
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("<== SolrStep.execute({})", context);
+        }
+    }
+
+    private Iterator<AtlasIndexQuery.Result> executeAgainstFulltextIndex(PipelineContext context) {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("==> SolrStep.executeAgainstFulltextIndex()");
+        }
+
+        final Iterator<AtlasIndexQuery.Result> ret;
+
+        AtlasIndexQuery query = context.getIndexQuery("FULLTEXT");
+
+        if (query == null) {
+            // Compute only once
+            SearchParameters searchParameters = context.getSearchParameters();
+            String           indexQuery       = String.format("v.\"%s\":(%s)", Constants.ENTITY_TEXT_PROPERTY_KEY, searchParameters.getQuery());
+
+            query = graph.indexQuery(Constants.FULLTEXT_INDEX, indexQuery);
+
+            context.cacheIndexQuery("FULLTEXT", query);
+        }
+
+        context.setIndexResultType(IndexResultType.TEXT);
+
+        ret = query.vertices(context.getCurrentOffset(), context.getMaxLimit());
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("<== SolrStep.executeAgainstFulltextIndex()");
+        }
+
+        return ret;
+    }
+
+    private Iterator<AtlasIndexQuery.Result> executeAgainstVertexIndex(PipelineContext context) {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("==> SolrStep.executeAgainstVertexIndex()");
+        }
+
+        final Iterator<AtlasIndexQuery.Result> ret;
+
+        SearchParameters searchParameters = context.getSearchParameters();
+        AtlasIndexQuery  query            = context.getIndexQuery("VERTEX_INDEX");
+
+        if (query == null) {
+            StringBuilder solrQuery = new StringBuilder();
+
+            // If tag is specified then let's start processing using tag and it's attributes, entity filters will
+            // be pushed to Gremlin
+            if (context.getClassificationType() != null) {
+                context.setIndexResultType(IndexResultType.TAG);
+
+                constructTypeTestQuery(solrQuery, context.getClassificationType().getTypeAndAllSubTypes());
+                constructFilterQuery(solrQuery, context.getClassificationType(), searchParameters.getTagFilters(), context);
+            } else if (context.getEntityType() != null) {
+                context.setIndexResultType(IndexResultType.ENTITY);
+
+                constructTypeTestQuery(solrQuery, context.getEntityType().getTypeAndAllSubTypes());
+                constructFilterQuery(solrQuery, context.getEntityType(), searchParameters.getEntityFilters(), context);
+
+                // Set the status flag
+                if (searchParameters.getExcludeDeletedEntities()) {
+                    if (solrQuery.length() > 0) {
+                        solrQuery.append(" AND ");
+                    }
+
+                    solrQuery.append("v.\"__state\":").append("ACTIVE");
+                }
+            }
+
+            // No query was formed, doesn't make sense to do anything beyond this point
+            if (solrQuery.length() > 0) {
+                String validSolrQuery = STRAY_AND_PATTERN.matcher(solrQuery).replaceAll(")");
+                validSolrQuery = STRAY_OR_PATTERN.matcher(validSolrQuery).replaceAll(")");
+                validSolrQuery = STRAY_ELIPSIS_PATTERN.matcher(validSolrQuery).replaceAll(EMPTY_STRING);
+
+                query = graph.indexQuery(Constants.VERTEX_INDEX, validSolrQuery);
+                context.cacheIndexQuery("VERTEX_INDEX", query);
+            }
+        }
+
+        // Execute solr query and return the index results in the context
+        if (query != null) {
+            ret = query.vertices(context.getCurrentOffset(), context.getMaxLimit());
+        } else {
+            ret = null;
+        }
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("<== SolrStep.executeAgainstVertexIndex()");
+        }
+
+        return ret;
+    }
+
+    private void constructTypeTestQuery(StringBuilder solrQuery, Set<String> typeAndAllSubTypes) {
+        String typeAndSubtypesString = StringUtils.join(typeAndAllSubTypes, SPACE_STRING);
+
+        solrQuery.append("v.\"__typeName\": (")
+                .append(typeAndSubtypesString)
+                .append(")");
+    }
+
+    private void constructFilterQuery(StringBuilder solrQuery, AtlasStructType type, FilterCriteria filterCriteria, PipelineContext context) {
+        if (filterCriteria != null) {
+            LOG.debug("Processing Filters");
+
+            String filterQuery = toSolrQuery(type, filterCriteria, context);
+
+            if (StringUtils.isNotEmpty(filterQuery)) {
+                solrQuery.append(AND_STR).append(filterQuery);
+            }
+        }
+    }
+
+    private String toSolrQuery(AtlasStructType type, FilterCriteria criteria, PipelineContext context) {
+        return toSolrQuery(type, criteria, context, new StringBuilder());
+    }
+
+    private String toSolrQuery(AtlasStructType type, FilterCriteria criteria, PipelineContext context, StringBuilder sb) {
+        if (criteria.getCondition() != null && CollectionUtils.isNotEmpty(criteria.getCriterion())) {
+            StringBuilder nestedExpression = new StringBuilder();
+
+            for (FilterCriteria filterCriteria : criteria.getCriterion()) {
+                String nestedQuery = toSolrQuery(type, filterCriteria, context);
+
+                if (StringUtils.isNotEmpty(nestedQuery)) {
+                    if (nestedExpression.length() > 0) {
+                        nestedExpression.append(SPACE_STRING).append(criteria.getCondition()).append(SPACE_STRING);
+                    }
+
+                    nestedExpression.append(nestedQuery);
+                }
+            }
+
+            return nestedExpression.length() > 0 ? sb.append(BRACE_OPEN_STR).append(nestedExpression.toString()).append(BRACE_CLOSE_STR).toString() : EMPTY_STRING;
+        } else {
+            return toSolrExpression(type, criteria.getAttributeName(), criteria.getOperator(), criteria.getAttributeValue(), context);
+        }
+    }
+
+    private String toSolrExpression(AtlasStructType type, String attrName, Operator op, String attrVal, PipelineContext context) {
+        String ret = EMPTY_STRING;
+
+        try {
+            String    indexKey      = type.getQualifiedAttributeName(attrName);
+            AtlasType attributeType = type.getAttributeType(attrName);
+
+            switch (context.getIndexResultType()) {
+                case TAG:
+                    context.addTagSearchAttribute(indexKey);
+                    break;
+
+                case ENTITY:
+                    context.addEntitySearchAttribute(indexKey);
+                    break;
+
+                default:
+                    // Do nothing
+            }
+
+            if (attributeType != null && AtlasTypeUtil.isBuiltInType(attributeType.getTypeName()) && context.getIndexedKeys().contains(indexKey)) {
+                if (operatorMap.get(op) != null) {
+                    // If there's a chance of multi-value then we need some additional processing here
+                    switch (context.getIndexResultType()) {
+                        case TAG:
+                            context.addProcessedTagAttribute(indexKey);
+                            break;
+
+                        case ENTITY:
+                            context.addProcessedEntityAttribute(indexKey);
+                            break;
+                    }
+
+                    ret = String.format(operatorMap.get(op), indexKey, attrVal);
+                }
+            }
+        } catch (AtlasBaseException ex) {
+            LOG.warn(ex.getMessage());
+        }
+
+        return ret;
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/repository/graph/GraphBackedSearchIndexer.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/repository/graph/GraphBackedSearchIndexer.java b/repository/src/main/java/org/apache/atlas/repository/graph/GraphBackedSearchIndexer.java
index 35dbf6c..94b6092 100755
--- a/repository/src/main/java/org/apache/atlas/repository/graph/GraphBackedSearchIndexer.java
+++ b/repository/src/main/java/org/apache/atlas/repository/graph/GraphBackedSearchIndexer.java
@@ -68,8 +68,10 @@ import java.math.BigInteger;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import static org.apache.atlas.model.typedef.AtlasBaseTypeDef.*;
 
@@ -96,7 +98,10 @@ public class GraphBackedSearchIndexer implements SearchIndexer, ActiveStateChang
 
     //allows injection of a dummy graph for testing
     private IAtlasGraphProvider provider;
-    
+
+    private boolean     recomputeIndexedKeys = true;
+    private Set<String> vertexIndexKeys      = new HashSet<>();
+
     @Inject
     public GraphBackedSearchIndexer(AtlasTypeRegistry typeRegistry) throws AtlasException {
         this(new AtlasGraphProvider(), ApplicationProperties.get(), typeRegistry);
@@ -130,6 +135,7 @@ public class GraphBackedSearchIndexer implements SearchIndexer, ActiveStateChang
             if (management.containsPropertyKey(Constants.VERTEX_TYPE_PROPERTY_KEY)) {
                 LOG.info("Global indexes already exist for graph");
                 management.commit();
+
                 return;
             }
 
@@ -192,7 +198,6 @@ public class GraphBackedSearchIndexer implements SearchIndexer, ActiveStateChang
             throw new RepositoryException(t);
         }
     }
-   
 
     private void createFullTextIndex(AtlasGraphManagement management) {
         AtlasPropertyKey fullText =
@@ -247,6 +252,34 @@ public class GraphBackedSearchIndexer implements SearchIndexer, ActiveStateChang
         onAdd(dataTypes);
     }
 
+    public Set<String> getVertexIndexKeys() {
+        if (recomputeIndexedKeys) {
+            AtlasGraphManagement management = null;
+
+            try {
+                management = provider.get().getManagementSystem();
+            } catch (RepositoryException excp) {
+                LOG.error("failed to get indexedKeys from graph", excp);
+            }
+
+            if (management != null) {
+                recomputeIndexedKeys = false;
+
+                AtlasGraphIndex vertexIndex = management.getGraphIndex(Constants.VERTEX_INDEX);
+
+                Set<String> indexKeys = new HashSet<>();
+
+                for (AtlasPropertyKey fieldKey : vertexIndex.getFieldKeys()) {
+                    indexKeys.add(fieldKey.getName());
+                }
+
+                vertexIndexKeys = indexKeys;
+            }
+        }
+
+        return vertexIndexKeys;
+    }
+
     private void addIndexForType(AtlasGraphManagement management, AtlasBaseTypeDef typeDef) {
         if (typeDef instanceof AtlasEnumDef) {
             // Only handle complex types like Struct, Classification and Entity
@@ -577,6 +610,8 @@ public class GraphBackedSearchIndexer implements SearchIndexer, ActiveStateChang
     private void commit(AtlasGraphManagement management) throws IndexException {
         try {
             management.commit();
+
+            recomputeIndexedKeys = true;
         } catch (Exception e) {
             LOG.error("Index commit failed", e);
             throw new IndexException("Index commit failed ", e);
@@ -586,6 +621,8 @@ public class GraphBackedSearchIndexer implements SearchIndexer, ActiveStateChang
     private void rollback(AtlasGraphManagement management) throws IndexException {
         try {
             management.rollback();
+
+            recomputeIndexedKeys = true;
         } catch (Exception e) {
             LOG.error("Index rollback failed ", e);
             throw new IndexException("Index rollback failed ", e);

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/repository/impexp/ImportService.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/repository/impexp/ImportService.java b/repository/src/main/java/org/apache/atlas/repository/impexp/ImportService.java
index 3411f8d..9221717 100644
--- a/repository/src/main/java/org/apache/atlas/repository/impexp/ImportService.java
+++ b/repository/src/main/java/org/apache/atlas/repository/impexp/ImportService.java
@@ -30,12 +30,14 @@ import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
 
+import javax.inject.Inject;
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 
-
+@Component
 public class ImportService {
     private static final Logger LOG = LoggerFactory.getLogger(ImportService.class);
 
@@ -46,6 +48,7 @@ public class ImportService {
     private long startTimestamp;
     private long endTimestamp;
 
+    @Inject
     public ImportService(final AtlasTypeDefStore typeDefStore, final AtlasEntityStore entityStore, AtlasTypeRegistry typeRegistry) {
         this.typeDefStore = typeDefStore;
         this.entityStore = entityStore;

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/AtlasGraphUtilsV1.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/AtlasGraphUtilsV1.java b/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/AtlasGraphUtilsV1.java
index 42bd58f..7b3f1e6 100644
--- a/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/AtlasGraphUtilsV1.java
+++ b/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/AtlasGraphUtilsV1.java
@@ -39,7 +39,10 @@ import org.apache.commons.lang.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.*;
+import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.Map;
 
 /**
  * Utility methods for Graph.

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/EntityGraphRetriever.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/EntityGraphRetriever.java b/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/EntityGraphRetriever.java
index 9a8695a..a5b5730 100644
--- a/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/EntityGraphRetriever.java
+++ b/repository/src/main/java/org/apache/atlas/repository/store/graph/v1/EntityGraphRetriever.java
@@ -46,10 +46,12 @@ import org.slf4j.LoggerFactory;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import static org.apache.atlas.model.typedef.AtlasBaseTypeDef.ATLAS_TYPE_BIGDECIMAL;
 import static org.apache.atlas.model.typedef.AtlasBaseTypeDef.ATLAS_TYPE_BIGINTEGER;
@@ -123,7 +125,7 @@ public final class EntityGraphRetriever {
     }
 
     public AtlasEntityHeader toAtlasEntityHeader(AtlasVertex entityVertex) throws AtlasBaseException {
-        return entityVertex != null ? mapVertexToAtlasEntityHeader(entityVertex) : null;
+        return toAtlasEntityHeader(entityVertex, Collections.<String>emptySet());
     }
 
     private AtlasVertex getEntityVertex(String guid) throws AtlasBaseException {
@@ -185,6 +187,10 @@ public final class EntityGraphRetriever {
     }
 
     private AtlasEntityHeader mapVertexToAtlasEntityHeader(AtlasVertex entityVertex) throws AtlasBaseException {
+        return mapVertexToAtlasEntityHeader(entityVertex, Collections.<String>emptySet());
+    }
+
+    private AtlasEntityHeader mapVertexToAtlasEntityHeader(AtlasVertex entityVertex, Set<String> attributes) throws AtlasBaseException {
         AtlasEntityHeader ret = new AtlasEntityHeader();
 
         String typeName = entityVertex.getProperty(Constants.TYPE_NAME_PROPERTY_KEY, String.class);
@@ -218,6 +224,20 @@ public final class EntityGraphRetriever {
             if (displayText != null) {
                 ret.setDisplayText(displayText.toString());
             }
+
+            if (CollectionUtils.isNotEmpty(attributes)) {
+                for (String attrName : attributes) {
+                    if (ret.hasAttribute(attrName)) {
+                        continue;
+                    }
+
+                    Object attrValue = getVertexAttribute(entityVertex, entityType.getAttribute(attrName));
+
+                    if (attrValue != null) {
+                        ret.setAttribute(attrName, attrValue);
+                    }
+                }
+            }
         }
 
         return ret;
@@ -556,4 +576,8 @@ public final class EntityGraphRetriever {
     private Object getVertexAttribute(AtlasVertex vertex, AtlasAttribute attribute) throws AtlasBaseException {
         return vertex != null && attribute != null ? mapVertexToAttribute(vertex, attribute, null) : null;
     }
+
+    public AtlasEntityHeader toAtlasEntityHeader(AtlasVertex atlasVertex, Set<String> attributes) throws AtlasBaseException {
+        return atlasVertex != null ? mapVertexToAtlasEntityHeader(atlasVertex, attributes) : null;
+    }
 }

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/main/java/org/apache/atlas/util/SearchTracker.java
----------------------------------------------------------------------
diff --git a/repository/src/main/java/org/apache/atlas/util/SearchTracker.java b/repository/src/main/java/org/apache/atlas/util/SearchTracker.java
new file mode 100644
index 0000000..15a8c20
--- /dev/null
+++ b/repository/src/main/java/org/apache/atlas/util/SearchTracker.java
@@ -0,0 +1,73 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.atlas.util;
+
+import org.apache.atlas.annotation.AtlasService;
+import org.apache.atlas.discovery.SearchPipeline.PipelineContext;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+@AtlasService
+public class SearchTracker {
+    private Map<String, PipelineContext> activeSearches = new HashMap<>();
+
+    /**
+     *
+     * @param context
+     */
+    public String add(PipelineContext context) {
+        String searchId = Thread.currentThread().getName();
+
+        activeSearches.put(searchId, context);
+
+        return searchId;
+    }
+
+    /**
+     *
+     * @param searchId
+     * @return
+     */
+    public PipelineContext terminate(String searchId) {
+        PipelineContext ret = null;
+
+        if (activeSearches.containsKey(searchId)) {
+            PipelineContext pipelineToTerminate = activeSearches.remove(searchId);
+
+            pipelineToTerminate.setForceTerminate(true);
+
+            ret = pipelineToTerminate;
+        }
+
+        return ret;
+    }
+
+    public PipelineContext remove(String id) {
+        return activeSearches.remove(id);
+    }
+
+    /**
+     *
+     * @return
+     */
+    public Set<String> getActiveSearches() {
+        return activeSearches.keySet();
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/test/java/org/apache/atlas/TestModules.java
----------------------------------------------------------------------
diff --git a/repository/src/test/java/org/apache/atlas/TestModules.java b/repository/src/test/java/org/apache/atlas/TestModules.java
index fa2ac0d..d0da030 100644
--- a/repository/src/test/java/org/apache/atlas/TestModules.java
+++ b/repository/src/test/java/org/apache/atlas/TestModules.java
@@ -17,19 +17,14 @@
  */
 package org.apache.atlas;
 
+import com.google.inject.AbstractModule;
 import com.google.inject.Binder;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import com.google.inject.matcher.Matchers;
 import com.google.inject.multibindings.Multibinder;
 import org.apache.atlas.annotation.GraphTransaction;
-import org.apache.atlas.discovery.AtlasDiscoveryService;
-import org.apache.atlas.discovery.AtlasLineageService;
-import org.apache.atlas.discovery.DataSetLineageService;
-import org.apache.atlas.discovery.DiscoveryService;
-import org.apache.atlas.discovery.EntityDiscoveryService;
-import org.apache.atlas.discovery.EntityLineageService;
-import org.apache.atlas.discovery.LineageService;
+import org.apache.atlas.discovery.*;
 import org.apache.atlas.discovery.graph.GraphBackedDiscoveryService;
 import org.apache.atlas.graph.GraphSandboxUtil;
 import org.apache.atlas.listener.EntityChangeListener;
@@ -61,6 +56,7 @@ import org.apache.atlas.type.AtlasTypeRegistry;
 import org.apache.atlas.typesystem.types.TypeSystem;
 import org.apache.atlas.typesystem.types.cache.TypeCache;
 import org.apache.atlas.util.AtlasRepositoryConfiguration;
+import org.apache.atlas.util.SearchTracker;
 import org.apache.commons.configuration.Configuration;
 import org.mockito.Mockito;
 import org.slf4j.Logger;
@@ -76,7 +72,7 @@ public class TestModules {
     }
 
     // Test only DI modules
-    public static class TestOnlyModule extends com.google.inject.AbstractModule {
+    public static class TestOnlyModule extends AbstractModule {
 
         private static final Logger LOG = LoggerFactory.getLogger(TestOnlyModule.class);
 
@@ -147,6 +143,11 @@ public class TestModules {
             typeDefChangeListenerMultibinder.addBinding().to(DefaultMetadataService.class);
             typeDefChangeListenerMultibinder.addBinding().to(GraphBackedSearchIndexer.class).asEagerSingleton();
 
+            bind(SearchPipeline.class).asEagerSingleton();
+            bind(SearchTracker.class).asEagerSingleton();
+            bind(SolrStep.class).asEagerSingleton();
+            bind(GremlinStep.class).asEagerSingleton();
+
             bind(AtlasEntityStore.class).to(AtlasEntityStoreV1.class);
             bind(AtlasRelationshipStore.class).to(AtlasRelationshipStoreV1.class);
 

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/repository/src/test/java/org/apache/atlas/services/EntityDiscoveryServiceTest.java
----------------------------------------------------------------------
diff --git a/repository/src/test/java/org/apache/atlas/services/EntityDiscoveryServiceTest.java b/repository/src/test/java/org/apache/atlas/services/EntityDiscoveryServiceTest.java
index 5d5b043..dfb2ee2 100644
--- a/repository/src/test/java/org/apache/atlas/services/EntityDiscoveryServiceTest.java
+++ b/repository/src/test/java/org/apache/atlas/services/EntityDiscoveryServiceTest.java
@@ -17,6 +17,7 @@
  */
 package org.apache.atlas.services;
 
+import org.apache.atlas.TestModules;
 import org.apache.atlas.discovery.EntityDiscoveryService;
 import org.apache.atlas.exception.AtlasBaseException;
 import org.apache.atlas.model.typedef.AtlasEntityDef;
@@ -24,12 +25,16 @@ import org.apache.atlas.type.AtlasTypeRegistry;
 import org.apache.commons.lang.StringUtils;
 import org.powermock.reflect.Whitebox;
 import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Guice;
 import org.testng.annotations.Test;
 
+import javax.inject.Inject;
+
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertNotNull;
 import static org.testng.Assert.assertTrue;
 
+@Guice(modules = TestModules.TestOnlyModule.class)
 public class EntityDiscoveryServiceTest {
 
     private final String TEST_TYPE                = "test";
@@ -47,6 +52,9 @@ public class EntityDiscoveryServiceTest {
 
     private final int maxTypesCountInIdxQuery = 10;
 
+    @Inject
+    EntityDiscoveryService discoveryService;
+
 
     @BeforeClass
     public void init() throws AtlasBaseException {

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/webapp/src/main/java/org/apache/atlas/web/filters/StaleTransactionCleanupFilter.java
----------------------------------------------------------------------
diff --git a/webapp/src/main/java/org/apache/atlas/web/filters/StaleTransactionCleanupFilter.java b/webapp/src/main/java/org/apache/atlas/web/filters/StaleTransactionCleanupFilter.java
index cdb9064..8e74d39 100644
--- a/webapp/src/main/java/org/apache/atlas/web/filters/StaleTransactionCleanupFilter.java
+++ b/webapp/src/main/java/org/apache/atlas/web/filters/StaleTransactionCleanupFilter.java
@@ -50,7 +50,7 @@ public class StaleTransactionCleanupFilter implements Filter {
     @Override
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
     throws IOException, ServletException {
-        LOG.info("Cleaning stale transactions");
+        LOG.debug("Cleaning stale transactions");
         AtlasGraphProvider.getGraphInstance().rollback();
         filterChain.doFilter(request, response);
     }

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/webapp/src/main/java/org/apache/atlas/web/resources/AdminResource.java
----------------------------------------------------------------------
diff --git a/webapp/src/main/java/org/apache/atlas/web/resources/AdminResource.java b/webapp/src/main/java/org/apache/atlas/web/resources/AdminResource.java
index 8c5623f..1a9f57a 100755
--- a/webapp/src/main/java/org/apache/atlas/web/resources/AdminResource.java
+++ b/webapp/src/main/java/org/apache/atlas/web/resources/AdminResource.java
@@ -25,6 +25,7 @@ import org.apache.atlas.AtlasErrorCode;
 import org.apache.atlas.authorize.AtlasActionTypes;
 import org.apache.atlas.authorize.AtlasResourceTypes;
 import org.apache.atlas.authorize.simple.AtlasAuthorizationUtils;
+import org.apache.atlas.discovery.SearchPipeline;
 import org.apache.atlas.exception.AtlasBaseException;
 import org.apache.atlas.model.impexp.AtlasExportRequest;
 import org.apache.atlas.model.impexp.AtlasExportResult;
@@ -35,11 +36,9 @@ import org.apache.atlas.repository.impexp.ExportService;
 import org.apache.atlas.repository.impexp.ImportService;
 import org.apache.atlas.repository.impexp.ZipSink;
 import org.apache.atlas.repository.impexp.ZipSource;
-import org.apache.atlas.repository.store.graph.AtlasEntityStore;
 import org.apache.atlas.services.MetricsService;
-import org.apache.atlas.store.AtlasTypeDefStore;
 import org.apache.atlas.type.AtlasType;
-import org.apache.atlas.type.AtlasTypeRegistry;
+import org.apache.atlas.util.SearchTracker;
 import org.apache.atlas.web.filters.AtlasCSRFPreventionFilter;
 import org.apache.atlas.web.service.ServiceState;
 import org.apache.atlas.web.util.Servlets;
@@ -51,7 +50,6 @@ import org.codehaus.jettison.json.JSONException;
 import org.codehaus.jettison.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.context.ApplicationContext;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.context.SecurityContextHolder;
@@ -62,9 +60,11 @@ import javax.inject.Singleton;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.ws.rs.Consumes;
+import javax.ws.rs.DELETE;
 import javax.ws.rs.GET;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
 import javax.ws.rs.WebApplicationException;
@@ -109,14 +109,10 @@ public class AdminResource {
 
     private final ServiceState      serviceState;
     private final MetricsService    metricsService;
-    private final AtlasTypeRegistry typeRegistry;
-    private final AtlasTypeDefStore typesDefStore;
-    private final AtlasEntityStore  entityStore;
     private static Configuration atlasProperties;
     private final ExportService exportService;
-
-    @Inject
-    ApplicationContext applicationContext;
+    private final ImportService importService;
+    private final SearchTracker activeSearches;
 
     static {
         try {
@@ -128,15 +124,13 @@ public class AdminResource {
 
     @Inject
     public AdminResource(ServiceState serviceState, MetricsService metricsService,
-                         AtlasTypeRegistry typeRegistry, AtlasTypeDefStore typeDefStore,
-                         AtlasEntityStore entityStore, ExportService exportService) {
+                         ExportService exportService, ImportService importService, SearchTracker activeSearches) {
         this.serviceState               = serviceState;
         this.metricsService             = metricsService;
-        this.typeRegistry               = typeRegistry;
-        this.typesDefStore              = typeDefStore;
-        this.entityStore                = entityStore;
         this.exportService = exportService;
-        this.importExportOperationLock  = new ReentrantLock();
+        this.importService = importService;
+        this.activeSearches = activeSearches;
+        importExportOperationLock = new ReentrantLock();
     }
 
     /**
@@ -377,7 +371,6 @@ public class AdminResource {
 
         try {
             AtlasImportRequest request = AtlasType.fromJson(jsonData, AtlasImportRequest.class);
-            ImportService importService = new ImportService(this.typesDefStore, this.entityStore, this.typeRegistry);
             ZipSource zipSource = new ZipSource(inputStream);
 
             result = importService.run(zipSource, request, Servlets.getUserName(httpServletRequest),
@@ -412,7 +405,6 @@ public class AdminResource {
 
         try {
             AtlasImportRequest request = AtlasType.fromJson(jsonData, AtlasImportRequest.class);
-            ImportService importService = new ImportService(this.typesDefStore, this.entityStore, this.typeRegistry);
             result = importService.run(request, Servlets.getUserName(httpServletRequest),
                                        Servlets.getHostName(httpServletRequest),
                                        AtlasAuthorizationUtils.getRequestIpAddress(httpServletRequest));
@@ -431,6 +423,21 @@ public class AdminResource {
         return result;
     }
 
+    @GET
+    @Path("activeSearches")
+    @Produces(Servlets.JSON_MEDIA_TYPE)
+    public Set<String> getActiveSearches() {
+        return activeSearches.getActiveSearches();
+    }
+
+    @DELETE
+    @Path("activeSearches/{id}")
+    @Produces(Servlets.JSON_MEDIA_TYPE)
+    public boolean terminateActiveSearch(@PathParam("id") String searchId) {
+        SearchPipeline.PipelineContext terminate = activeSearches.terminate(searchId);
+        return null != terminate;
+    }
+
     private String getEditableEntityTypes(Configuration config) {
         String ret = DEFAULT_EDITABLE_ENTITY_TYPES;
 

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/webapp/src/main/java/org/apache/atlas/web/rest/DiscoveryREST.java
----------------------------------------------------------------------
diff --git a/webapp/src/main/java/org/apache/atlas/web/rest/DiscoveryREST.java b/webapp/src/main/java/org/apache/atlas/web/rest/DiscoveryREST.java
index ea55021..dde300e 100644
--- a/webapp/src/main/java/org/apache/atlas/web/rest/DiscoveryREST.java
+++ b/webapp/src/main/java/org/apache/atlas/web/rest/DiscoveryREST.java
@@ -21,8 +21,10 @@ import org.apache.atlas.AtlasErrorCode;
 import org.apache.atlas.exception.AtlasBaseException;
 import org.apache.atlas.discovery.AtlasDiscoveryService;
 import org.apache.atlas.model.discovery.AtlasSearchResult;
+import org.apache.atlas.model.discovery.SearchParameters;
 import org.apache.atlas.utils.AtlasPerfTracer;
 import org.apache.atlas.web.util.Servlets;
+import org.apache.commons.collections.CollectionUtils;
 import org.springframework.stereotype.Service;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
@@ -31,6 +33,7 @@ import javax.inject.Inject;
 import javax.inject.Singleton;
 import javax.ws.rs.Consumes;
 import javax.ws.rs.GET;
+import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
@@ -213,6 +216,50 @@ public class DiscoveryREST {
         }
     }
 
+    /**
+     * Attribute based search for entities satisfying the search parameters
+     * @param parameters Search parameters
+     * @return Atlas search result
+     * @throws AtlasBaseException
+     *
+     * @HTTP 200 On successful search
+     * @HTTP 400 Tag/Entity doesn't exist or Tag/entity filter is present without tag/type name
+     */
+    @Path("basic")
+    @POST
+    @Consumes(Servlets.JSON_MEDIA_TYPE)
+    @Produces(Servlets.JSON_MEDIA_TYPE)
+    public AtlasSearchResult searchWithParameters(SearchParameters parameters) throws AtlasBaseException {
+        AtlasPerfTracer perf = null;
+
+        try {
+            if (AtlasPerfTracer.isPerfTraceEnabled(PERF_LOG)) {
+                perf = AtlasPerfTracer.getPerfTracer(PERF_LOG, "DiscoveryREST.searchWithParameters("+ parameters + ")");
+            }
+
+            if (parameters.getLimit() < 0 || parameters.getOffset() < 0) {
+                throw new AtlasBaseException(AtlasErrorCode.BAD_REQUEST, "Limit/offset should be non-negative");
+            }
+
+            if (StringUtils.isEmpty(parameters.getTypeName()) && !isEmpty(parameters.getEntityFilters())) {
+                throw new AtlasBaseException(AtlasErrorCode.BAD_REQUEST, "EntityFilters specified without Type name");
+            }
+
+            if (StringUtils.isEmpty(parameters.getClassification()) && !isEmpty(parameters.getTagFilters())) {
+                throw new AtlasBaseException(AtlasErrorCode.BAD_REQUEST, "TagFilters specified without tag name");
+            }
+
+            return atlasDiscoveryService.searchUsingBasicQuery(parameters);
+        } finally {
+            AtlasPerfTracer.log(perf);
+        }
+    }
+
+    private boolean isEmpty(SearchParameters.FilterCriteria filterCriteria) {
+        return filterCriteria == null ||
+               (StringUtils.isEmpty(filterCriteria.getAttributeName()) && CollectionUtils.isEmpty(filterCriteria.getCriterion()));
+    }
+
     private String escapeTypeName(String typeName) {
         String ret;
 

http://git-wip-us.apache.org/repos/asf/incubator-atlas/blob/7c262b40/webapp/src/test/java/org/apache/atlas/web/resources/AdminResourceTest.java
----------------------------------------------------------------------
diff --git a/webapp/src/test/java/org/apache/atlas/web/resources/AdminResourceTest.java b/webapp/src/test/java/org/apache/atlas/web/resources/AdminResourceTest.java
index 1fe3119..c0bbf09 100644
--- a/webapp/src/test/java/org/apache/atlas/web/resources/AdminResourceTest.java
+++ b/webapp/src/test/java/org/apache/atlas/web/resources/AdminResourceTest.java
@@ -48,7 +48,7 @@ public class AdminResourceTest {
 
         when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.ACTIVE);
 
-        AdminResource adminResource = new AdminResource(serviceState, null, null, null, null, null);
+        AdminResource adminResource = new AdminResource(serviceState, null, null, null, null);
         Response response = adminResource.getStatus();
         assertEquals(response.getStatus(), HttpServletResponse.SC_OK);
         JSONObject entity = (JSONObject) response.getEntity();
@@ -59,7 +59,7 @@ public class AdminResourceTest {
     public void testResourceGetsValueFromServiceState() throws JSONException {
         when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
 
-        AdminResource adminResource = new AdminResource(serviceState, null, null, null, null, null);
+        AdminResource adminResource = new AdminResource(serviceState, null, null, null, null);
         Response response = adminResource.getStatus();
 
         verify(serviceState).getState();