cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "basanth gowda (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-4532) NPE when trying to select a slice from a composite table
Date Thu, 06 Sep 2012 16:01:07 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-4532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13449764#comment-13449764
] 

basanth gowda commented on CASSANDRA-4532:
------------------------------------------

Sylvian,
Thanks for the fix, May be I should have opened the ticket differently. My main issue is not
that the connection on cqlsh was getting closed (because of NPE) or exception being thrown
in thrift client. To adopt CQL3 mainstream slice with paging is need, I saw some other ticket,
where this proposal was there. 

Main reason I opened the ticket was for not being able to slice (rather no syntax support
for that, to continue where the last query left off). This is a piece of code that was written
using Hector and my assumption is the filtering was done on server side. We are using this
in production. I modified attributes (to get rid of proprietary stuff, so may be broken, but
should give an idea of what I was trying to do with CQL3)

            long cStartTime = 0L;
            long startTime = System.nanoTime();
            boolean fetchNextBatch = true;
            int totalKeysFetched = 0;
            String lastKeyFetched = null;
            long cEndTime = <Some Time in Millis>;
            while(fetchNextBatch) {
                fetchNextBatch = false;
                int pageSize = 3; //Just for demonstration
                SliceQuery<Object,DynamicComposite,String> sliceQuery =   HFactory.createSliceQuery(keyspace,cassCFConfig.getKeySerializer(),DynamicCompositeSerializer.get(),StringSerializer.get());
                sliceQuery.setKey("C");
                sliceQuery.setColumnFamily("<SOME CF NAME>");
                DynamicComposite startRange = new DynamicComposite();
  
                startRange.addComponent(cStartTime,LongSerializer.get()); //For the first
fetch - this will be 0L
                startRange.addComponent(lastKeyFetched,StringSerializer.get()); // this will
be null for first fetch

                DynamicComposite endRange = new DynamicComposite();
                endRange.addComponent(new Long(cEndTime), LongSerializer.get(), "LongType",
AbstractComposite.ComponentEquality.LESS_THAN_EQUAL);
                //Add another config if we need columnPageSize
                sliceQuery.setRange(startRange,endRange,false,pageSize);

                long start = System.nanoTime();
                QueryResult<ColumnSlice<DynamicComposite, String>> result = sliceQuery.execute();
                float t =  (float)((System.nanoTime() - start)/1000000);
                System.out.println("TIME FOR QUERY :" + t  + " MILLI SECONDS");

                ColumnSlice<DynamicComposite, String> cs = result.get();
                List<HColumn<DynamicComposite,String>> compositeList = cs.getColumns();

                for(int i =0;i<compositeList.size();i++) {
                    HColumn<DynamicComposite, String> col = compositeList.get(i);
                    cStartTime = col.getName().get(0,LongSerializer.get()); //This will be
the cTime for the start range of the next query
                    lastKeyFetched = col.getName().get(1,StringSerializer.get()); //In the
start range for the next query, this key will be used.
                    keyTimeMap.put(lastKeyFetched,scheduleStartTime);
                    totalKeysFetched ++;
                }

                //Process Fetched Data 

                fetchNextBatch = compositeList.size() == pageSize; // If the number of records
retrieved is equal to the page size, then there are probably more records left 
            }
                
> NPE when trying to select a slice from a composite table
> --------------------------------------------------------
>
>                 Key: CASSANDRA-4532
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4532
>             Project: Cassandra
>          Issue Type: Bug
>          Components: API, Core
>    Affects Versions: 1.1.3
>         Environment: Cassandra 1.1.3 (2 nodes) on a single host - mac osx
>            Reporter: basanth gowda
>            Assignee: Sylvain Lebresne
>            Priority: Minor
>              Labels: Slice, cql, cql3
>             Fix For: 1.1.6
>
>         Attachments: 4532.txt
>
>
> I posted this question on StackOverflow, because i need a solution. 
> Created a table with :
> {noformat}
> create table compositetest(m_id ascii,i_id int,l_id ascii,body ascii, PRIMARY KEY(m_id,i_id,l_id));
> {noformat}
> wanted to slice the results returned, so did something like below, not sure if its the
right way. The first one returns data perfectly as expected, second one to get the next 3
columns closes the transport of my cqlsh
> {noformat}
> cqlsh:testkeyspace1> select * from compositetest where i_id<=3 limit 3;
>  m_id | i_id | l_id | body
> ------+------+------+------
>    m1 |    1 |   l1 |   b1
>    m1 |    2 |   l2 |   b2
>    m2 |    1 |   l1 |   b1
> cqlsh:testkeyspace1> Was trying to write something for slice range.
> TSocket read 0 bytes
> {noformat}
> Is there a way to achieve what I am doing here, it would be good if some meaning ful
error is sent back, instead of cqlsh closing the transport.
> On the server side I see the following error.
> {noformat}
> ERROR [Thrift:3] 2012-08-12 15:15:24,414 CustomTThreadPoolServer.java (line 204) Error
occurred during processing of message.
> java.lang.NullPointerException
> 	at org.apache.cassandra.cql3.statements.SelectStatement$Restriction.setBound(SelectStatement.java:1277)
> 	at org.apache.cassandra.cql3.statements.SelectStatement$RawStatement.updateRestriction(SelectStatement.java:1151)
> 	at org.apache.cassandra.cql3.statements.SelectStatement$RawStatement.prepare(SelectStatement.java:1001)
> 	at org.apache.cassandra.cql3.QueryProcessor.getStatement(QueryProcessor.java:215)
> 	at org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:121)
> 	at org.apache.cassandra.thrift.CassandraServer.execute_cql_query(CassandraServer.java:1237)
> 	at org.apache.cassandra.thrift.Cassandra$Processor$execute_cql_query.getResult(Cassandra.java:3542)
> 	at org.apache.cassandra.thrift.Cassandra$Processor$execute_cql_query.getResult(Cassandra.java:3530)
> 	at org.apache.thrift.ProcessFunction.process(ProcessFunction.java:32)
> 	at org.apache.thrift.TBaseProcessor.process(TBaseProcessor.java:34)
> 	at org.apache.cassandra.thrift.CustomTThreadPoolServer$WorkerProcess.run(CustomTThreadPoolServer.java:186)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
> 	at java.lang.Thread.run(Thread.java:680)
> {noformat}
> With ThriftClient I get :
> {noformat}
> org.apache.thrift.transport.TTransportException
> 	at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:132)
> 	at org.apache.thrift.transport.TTransport.readAll(TTransport.java:84)
> 	at org.apache.thrift.transport.TFramedTransport.readFrame(TFramedTransport.java:129)
> 	at org.apache.thrift.transport.TFramedTransport.read(TFramedTransport.java:101)
> 	at org.apache.thrift.transport.TTransport.readAll(TTransport.java:84)
> 	at org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:378)
> 	at org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:297)
> 	at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:204)
> 	at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:69)
> 	at org.apache.cassandra.thrift.Cassandra$Client.recv_execute_cql_query(Cassandra.java:1402)
> 	at org.apache.cassandra.thrift.Cassandra$Client.execute_cql_query(Cassandra.java:1388)
> {noformat}

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message