14. Appendix A: Configuration Management

14.1. Configuration Overview

All accumulo properties have a default value in the source code. Properties can also be set +in accumulo-site.xml and in zookeeper on per-table or system-wide basis. If properties are set in more than one location, +accumulo will choose the property with the highest precedence. This order of precedence is described +below (from highest to lowest):

14.1.1. Zookeeper table properties

Table properties are applied to the entire cluster when set in zookeeper using the accumulo API or shell. While table properties take precedent over system properties, both will override properties set in accumulo-site.xml

Table properties consist of all properties with the table.* prefix. Table properties are configured on a per-table basis using the following shell commmand:

config -t TABLE -s PROPERTY=VALUE

14.1.2. Zookeeper system properties

System properties are applied to the entire cluster when set in zookeeper using the accumulo API or shell. System properties consist of all properties with a yes in the Zookeeper Mutable column in the table below. They are set with the following shell command:

config -s PROPERTY=VALUE

If a table.* property is set using this method, the value will apply to all tables except those configured on per-table basis (which have higher precedence).

While most system properties take effect immediately, some require a restart of the process which is indicated in Zookeeper Mutable.

14.1.3. accumulo-site.xml

Accumulo processes (master, tserver, etc) read their local accumulo-site.xml on start up. Therefore, changes made to accumulo-site.xml must rsynced across the cluster and processes must be restarted to apply changes.

Certain properties (indicated by a no in Zookeeper Mutable) cannot be set in zookeeper and only set in this file. The accumulo-site.xml also allows you to configure tablet servers with different settings.

14.1.4. Default Values

All properties have a default value in the source code. This value has the lowest precedence and is overriden if set in accumulo-site.xml or zookeeper.

While the default value is usually optimal, there are cases where a change can increase query and ingest performance.

14.2. Configuration in the Shell

The config command in the shell allows you to view the current system configuration. You can also use the -t option to view a table’s configuration as below:

$ ./bin/accumulo shell -u root
+Enter current password for 'root'@'accumulo-instance': ******
+
+Shell - Apache Accumulo Interactive Shell
+-
+- version: 1.6.0
+- instance name: accumulo-instance
+- instance id: 4f48fa03-f692-43ce-ae03-94c9ea8b7181
+-
+- type 'help' for a list of available commands
+-
+root@accumulo-instance> config -t foo
+---------+---------------------------------------------+------------------------------------------------------
+SCOPE    | NAME                                        | VALUE
+---------+---------------------------------------------+------------------------------------------------------
+default  | table.balancer ............................ | org.apache.accumulo.server.master.balancer.DefaultLoadBalancer
+default  | table.bloom.enabled ....................... | false
+default  | table.bloom.error.rate .................... | 0.5%
+default  | table.bloom.hash.type ..................... | murmur
+default  | table.bloom.key.functor ................... | org.apache.accumulo.core.file.keyfunctor.RowFunctor
+default  | table.bloom.load.threshold ................ | 1
+default  | table.bloom.size .......................... | 1048576
+default  | table.cache.block.enable .................. | false
+default  | table.cache.index.enable .................. | false
+default  | table.compaction.major.everything.at ...... | 19700101000000GMT
+default  | table.compaction.major.everything.idle .... | 1h
+default  | table.compaction.major.ratio .............. | 1.3
+site     |    @override .............................. | 1.4
+system   |    @override .............................. | 1.5
+table    |    @override .............................. | 1.6
+default  | table.compaction.minor.idle ............... | 5m
+default  | table.compaction.minor.logs.threshold ..... | 3
+default  | table.failures.ignore ..................... | false

14.3. Available Properties

14.3.1. rpc.*

Properties in this category related to the configuration of SSL keys for RPC. See also instance.ssl.enabled

rpc.javax.net.ssl.keyStore

Path of the keystore file for the servers' private SSL key

Type: PATH
+Zookeeper Mutable: no
+Default Value: $ACCUMULO_CONF_DIR/ssl/keystore.jks

rpc.javax.net.ssl.keyStorePassword

Password used to encrypt the SSL private keystore. Leave blank to use the Accumulo instance secret

Type: STRING
+Zookeeper Mutable: no
+Default Value: empty

rpc.javax.net.ssl.keyStoreType

Type of SSL keystore

Type: STRING
+Zookeeper Mutable: no
+Default Value: jks

rpc.javax.net.ssl.trustStore

Path of the truststore file for the root cert

Type: PATH
+Zookeeper Mutable: no
+Default Value: $ACCUMULO_CONF_DIR/ssl/truststore.jks

rpc.javax.net.ssl.trustStorePassword

Password used to encrypt the SSL truststore. Leave blank to use no password

Type: STRING
+Zookeeper Mutable: no
+Default Value: empty

rpc.javax.net.ssl.trustStoreType

Type of SSL truststore

Type: STRING
+Zookeeper Mutable: no
+Default Value: jks

rpc.useJsse

Use JSSE system properties to configure SSL rather than the rpc.javax.net.ssl.* Accumulo properties

Type: BOOLEAN
+Zookeeper Mutable: no
+Default Value: false

14.3.2. instance.*

Properties in this category must be consistent throughout a cloud. This is enforced and servers won’t be able to communicate if these differ.

instance.dfs.dir

Deprecated. HDFS directory in which accumulo instance will run. Do not change after accumulo is initialized.

Type: ABSOLUTEPATH
+Zookeeper Mutable: no
+Default Value: /accumulo

instance.dfs.uri

Deprecated. A url accumulo should use to connect to DFS. If this is empty, accumulo will obtain this information from the hadoop configuration. This property will only be used when creating new files if instance.volumes is empty. After an upgrade to 1.6.0 Accumulo will start using absolute paths to reference files. Files created before a 1.6.0 upgrade are referenced via relative paths. Relative paths will always be resolved using this config (if empty using the hadoop config).

Type: URI
+Zookeeper Mutable: no
+Default Value: empty

instance.rpc.ssl.clientAuth

Require clients to present certs signed by a trusted root

Type: BOOLEAN
+Zookeeper Mutable: no
+Default Value: false

instance.rpc.ssl.enabled

Use SSL for socket connections from clients and among accumulo services

Type: BOOLEAN
+Zookeeper Mutable: no
+Default Value: false

instance.secret

A secret unique to a given instance that all servers must know in order to communicate with one another. Change it before initialization. To change it later use ./bin/accumulo accumulo.server.util.ChangeSecret [oldpasswd] [newpasswd], and then update conf/accumulo-site.xml everywhere.

Type: STRING
+Zookeeper Mutable: no
+Default Value: DEFAULT

instance.security.authenticator

The authenticator class that accumulo will use to determine if a user has privilege to perform an action

Type: CLASSNAME
+Zookeeper Mutable: no
+Default Value: org.apache.accumulo.server.security.handler.ZKAuthenticator

instance.security.authorizor

The authorizor class that accumulo will use to determine what labels a user has privilege to see

Type: CLASSNAME
+Zookeeper Mutable: no
+Default Value: org.apache.accumulo.server.security.handler.ZKAuthorizor

instance.security.permissionHandler

The permission handler class that accumulo will use to determine if a user has privilege to perform an action

Type: CLASSNAME
+Zookeeper Mutable: no
+Default Value: org.apache.accumulo.server.security.handler.ZKPermHandler

instance.volumes

A comma seperated list of dfs uris to use. Files will be stored across these filesystems. If this is empty, then instance.dfs.uri will be used. After adding uris to this list, run accumulo init --add-volume and then restart tservers. If entries are removed from this list then tservers will need to be restarted. After a uri is removed from the list Accumulo will not create new files in that location, however Accumulo can still reference files created at that location before the config change. To use a comma or other reserved characters in a URI use standard URI hex encoding. For example replace commas with %2C.

Type: STRING
+Zookeeper Mutable: no
+Default Value: empty

instance.volumes.replacements

Since accumulo stores absolute URIs changing the location of a namenode could prevent Accumulo from starting. The property helps deal with that situation. Provide a comma seperated list of uri replacement pairs here if a namenode location changes. Each pair shold be separated with a space. For example, if hdfs://nn1 was repalced with hdfs://nnA and hdfs://nn2 was replaced with hdfs://nnB, then set this property to hdfs://nn1 hdfs://nnA,hdfs://nn2 hdfs://nnB’Replacements must be configured for use. To see which volumes are currently in use, run 'accumulo admin volumes -l. To use a comma or other reserved characters in a URI use standard URI hex encoding. For example replace commas with %2C.

Type: STRING
+Zookeeper Mutable: no
+Default Value: empty

instance.zookeeper.host

Comma separated list of zookeeper servers

Type: HOSTLIST
+Zookeeper Mutable: no
+Default Value: localhost:2181

instance.zookeeper.timeout

Zookeeper session timeout; max value when represented as milliseconds should be no larger than 2147483647

Type: TIMEDURATION
+Zookeeper Mutable: no
+Default Value: 30s

14.3.3. general.*

Properties in this category affect the behavior of accumulo overall, but do not have to be consistent throughout a cloud.

general.classpaths

A list of all of the places to look for a class. Order does matter, as it will look for the jar starting in the first location to the last. Please note, hadoop conf and hadoop lib directories NEED to be here, along with accumulo lib and zookeeper directory. Supports full regex on filename alone.

Type: STRING
+Zookeeper Mutable: no
+Default Value:

$ACCUMULO_CONF_DIR,
+$ACCUMULO_HOME/lib/[^.].*.jar,
+$ZOOKEEPER_HOME/zookeeper[^.].*.jar,
+$HADOOP_CONF_DIR,
+$HADOOP_PREFIX/[^.].*.jar,
+$HADOOP_PREFIX/lib/[^.].*.jar,
+$HADOOP_PREFIX/share/hadoop/common/.*.jar,
+$HADOOP_PREFIX/share/hadoop/common/lib/.*.jar,
+$HADOOP_PREFIX/share/hadoop/hdfs/.*.jar,
+$HADOOP_PREFIX/share/hadoop/mapreduce/.*.jar,
+/usr/lib/hadoop/[^.].*.jar,
+/usr/lib/hadoop/lib/[^.].*.jar,
+/usr/lib/hadoop-hdfs/[^.].*.jar,
+/usr/lib/hadoop-mapreduce/[^.].*.jar,
+/usr/lib/hadoop-yarn/[^.].*.jar,

general.dynamic.classpaths

A list of all of the places where changes in jars or classes will force a reload of the classloader.

Type: STRING
+Zookeeper Mutable: no
+Default Value: $ACCUMULO_HOME/lib/ext/[^.].*.jar

general.kerberos.keytab

Path to the kerberos keytab to use. Leave blank if not using kerberoized hdfs

Type: PATH
+Zookeeper Mutable: no
+Default Value: empty

general.kerberos.principal

Name of the kerberos principal to use. _HOST will automatically be replaced by the machines hostname in the hostname portion of the principal. Leave blank if not using kerberoized hdfs

Type: STRING
+Zookeeper Mutable: no
+Default Value: empty

general.rpc.timeout

Time to wait on I/O for simple, short RPC calls

Type: TIMEDURATION
+Zookeeper Mutable: no
+Default Value: 120s

general.server.message.size.max

The maximum size of a message that can be sent to a server.

Type: MEMORY
+Zookeeper Mutable: no
+Default Value: 1G

general.server.simpletimer.threadpool.size

The number of threads to use for server-internal scheduled tasks

Type: COUNT
+Zookeeper Mutable: no
+Default Value: 1

general.vfs.cache.dir

Directory to use for the vfs cache. The cache will keep a soft reference to all of the classes loaded in the VM. This should be on local disk on each node with sufficient space. It defaults to ${java.io.tmpdir}/accumulo-vfs-cache-${user.name}

Type: ABSOLUTEPATH
+Zookeeper Mutable: no
+Default Value: ${java.io.tmpdir}/accumulo-vfs-cache-${user.name}

general.vfs.classpaths

Configuration for a system level vfs classloader. Accumulo jar can be configured here and loaded out of HDFS.

Type: STRING
+Zookeeper Mutable: no
+Default Value: empty

14.3.4. master.*

Properties in this category affect the behavior of the master server

master.bulk.retries

The number of attempts to bulk-load a file before giving up.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 3

master.bulk.threadpool.size

The number of threads to use when coordinating a bulk-import.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 5

master.bulk.timeout

The time to wait for a tablet server to process a bulk import request

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 5m

master.fate.threadpool.size

The number of threads used to run FAult-Tolerant Executions. These are primarily table operations like merge.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 4

master.lease.recovery.interval

The amount of time to wait after requesting a WAL file to be recovered

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 5s

master.port.client

The port used for handling client connections on the master

Type: PORT
+Zookeeper Mutable: yes but requires restart of the master
+Default Value: 9999

master.recovery.delay

When a tablet server’s lock is deleted, it takes time for it to completely quit. This delay gives it time before log recoveries begin.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 10s

master.recovery.max.age

Recovery files older than this age will be removed.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 60m

master.recovery.time.max

The maximum time to attempt recovery before giving up

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 30m

master.server.threadcheck.time

The time between adjustments of the server thread pool.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 1s

master.server.threads.minimum

The minimum number of threads to use to handle incoming requests.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 20

master.tablet.balancer

The balancer class that accumulo will use to make tablet assignment and migration decisions.

Type: CLASSNAME
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.server.master.balancer.TableLoadBalancer

master.walog.closer.implementation

A class that implements a mechansim to steal write access to a file

Type: CLASSNAME
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.server.master.recovery.HadoopLogCloser

14.3.5. tserver.*

Properties in this category affect the behavior of the tablet servers

tserver.archive.walogs

Keep copies of the WALOGs for debugging purposes

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: false

tserver.bloom.load.concurrent.max

The number of concurrent threads that will load bloom filters in the background. Setting this to zero will make bloom filters load in the foreground.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 4

tserver.bulk.assign.threads

The master delegates bulk file processing and assignment to tablet servers. After the bulk file has been processed, the tablet server will assign the file to the appropriate tablets on all servers. This property controls the number of threads used to communicate to the other servers.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 1

tserver.bulk.process.threads

The master will task a tablet server with pre-processing a bulk file prior to assigning it to the appropriate tablet servers. This configuration value controls the number of threads used to process the files.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 1

tserver.bulk.retry.max

The number of times the tablet server will attempt to assign a file to a tablet as it migrates and splits.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 5

tserver.bulk.timeout

The time to wait for a tablet server to process a bulk import request.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 5m

tserver.cache.data.size

Specifies the size of the cache for file data blocks.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 128M

tserver.cache.index.size

Specifies the size of the cache for file indices.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 512M

tserver.client.timeout

Time to wait for clients to continue scans before closing a session.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 3s

tserver.compaction.major.concurrent.max

The maximum number of concurrent major compactions for a tablet server

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 3

tserver.compaction.major.delay

Time a tablet server will sleep between checking which tablets need compaction.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 30s

tserver.compaction.major.thread.files.open.max

Max number of files a major compaction thread can open at once.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 10

tserver.compaction.minor.concurrent.max

The maximum number of concurrent minor compactions for a tablet server

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 4

tserver.compaction.warn.time

When a compaction has not made progress for this time period, a warning will be logged

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 10m

tserver.default.blocksize

Specifies a default blocksize for the tserver caches

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 1M

tserver.dir.memdump

A long running scan could possibly hold memory that has been minor compacted. To prevent this, the in memory map is dumped to a local file and the scan is switched to that local file. We can not switch to the minor compacted file because it may have been modified by iterators. The file dumped to the local dir is an exact copy of what was in memory.

Type: PATH
+Zookeeper Mutable: yes
+Default Value: /tmp

tserver.files.open.idle

Tablet servers leave previously used files open for future queries. This setting determines how much time an unused file should be kept open until it is closed.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 1m

tserver.hold.time.max

The maximum time for a tablet server to be in the "memory full" state. If the tablet server cannot write out memory in this much time, it will assume there is some failure local to its node, and quit. A value of zero is equivalent to forever.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 5m

tserver.memory.manager

An implementation of MemoryManger that accumulo will use.

Type: CLASSNAME
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.server.tabletserver.LargestFirstMemoryManager

tserver.memory.maps.max

Maximum amount of memory that can be used to buffer data written to a tablet server. There are two other properties that can effectively limit memory usage table.compaction.minor.logs.threshold and tserver.walog.max.size. Ensure that table.compaction.minor.logs.threshold * tserver.walog.max.size >= this property.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 1G

tserver.memory.maps.native.enabled

An in-memory data store for accumulo implemented in c++ that increases the amount of data accumulo can hold in memory and avoids Java GC pauses.

Type: BOOLEAN
+Zookeeper Mutable: yes but requires restart of the tserver
+Default Value: true

tserver.metadata.readahead.concurrent.max

The maximum number of concurrent metadata read ahead that will execute.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 8

tserver.migrations.concurrent.max

The maximum number of concurrent tablet migrations for a tablet server

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 1

tserver.monitor.fs

When enabled the tserver will monitor file systems and kill itself when one switches from rw to ro. This is usually and indication that Linux has detected a bad disk.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: true

tserver.mutation.queue.max

The amount of memory to use to store write-ahead-log mutations-per-session before flushing them. Since the buffer is per write session, consider the max number of concurrent writer when configuring. When using Hadoop 2, Accumulo will call hsync() on the WAL . For a small number of concurrent writers, increasing this buffer size decreases the frequncy of hsync calls. For a large number of concurrent writers a small buffers size is ok because of group commit.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 1M

tserver.port.client

The port used for handling client connections on the tablet servers

Type: PORT
+Zookeeper Mutable: yes but requires restart of the tserver
+Default Value: 9997

tserver.port.search

if the ports above are in use, search higher ports until one is available

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: false

tserver.readahead.concurrent.max

The maximum number of concurrent read ahead that will execute. This effectively limits the number of long running scans that can run concurrently per tserver.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 16

tserver.recovery.concurrent.max

The maximum number of threads to use to sort logs during recovery

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 2

tserver.scan.files.open.max

Maximum total files that all tablets in a tablet server can open for scans.

Type: COUNT
+Zookeeper Mutable: yes but requires restart of the tserver
+Default Value: 100

tserver.server.message.size.max

The maximum size of a message that can be sent to a tablet server.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 1G

tserver.server.threadcheck.time

The time between adjustments of the server thread pool.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 1s

tserver.server.threads.minimum

The minimum number of threads to use to handle incoming requests.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 20

tserver.session.idle.max

maximum idle time for a session

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 1m

tserver.sort.buffer.size

The amount of memory to use when sorting logs during recovery.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 200M

tserver.tablet.split.midpoint.files.max

To find a tablets split points, all index files are opened. This setting determines how many index files can be opened at once. When there are more index files than this setting multiple passes must be made, which is slower. However opening too many files at once can cause problems.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 30

tserver.wal.blocksize

The size of the HDFS blocks used to write to the Write-Ahead log. If zero, it will be 110% of tserver.walog.max.size (that is, try to use just one block)

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 0

tserver.wal.replication

The replication to use when writing the Write-Ahead log to HDFS. If zero, it will use the HDFS default replication setting.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 0

tserver.wal.sync

Use the SYNC_BLOCK create flag to sync WAL writes to disk. Prevents problems recovering from sudden system resets.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: true

tserver.walog.max.size

The maximum size for each write-ahead log. See comment for property tserver.memory.maps.max

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 1G

tserver.workq.threads

The number of threads for the distributed work queue. These threads are used for copying failed bulk files.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 2

14.3.6. logger.*

Properties in this category affect the behavior of the write-ahead logger servers

logger.dir.walog

The property only needs to be set if upgrading from 1.4 which used to store write-ahead logs on the local filesystem. In 1.5 write-ahead logs are stored in DFS. When 1.5 is started for the first time it will copy any 1.4 write ahead logs into DFS. It is possible to specify a comma-separated list of directories.

Type: PATH
+Zookeeper Mutable: yes
+Default Value: walogs

14.3.7. gc.*

Properties in this category affect the behavior of the accumulo garbage collector.

gc.cycle.delay

Time between garbage collection cycles. In each cycle, old files no longer in use are removed from the filesystem.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 5m

gc.cycle.start

Time to wait before attempting to garbage collect any old files.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 30s

gc.port.client

The listening port for the garbage collector’s monitor service

Type: PORT
+Zookeeper Mutable: yes but requires restart of the gc
+Default Value: 50091

gc.threads.delete

The number of threads used to delete files

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 16

gc.trash.ignore

Do not use the Trash, even if it is configured

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: false

14.3.8. monitor.*

Properties in this category affect the behavior of the monitor web server.

monitor.banner.background

The background color of the banner text displayed on the monitor page.

Type: STRING
+Zookeeper Mutable: yes
+Default Value: #304065

monitor.banner.color

The color of the banner text displayed on the monitor page.

Type: STRING
+Zookeeper Mutable: yes
+Default Value: #c4c4c4

monitor.banner.text

The banner text displayed on the monitor page.

Type: STRING
+Zookeeper Mutable: yes
+Default Value: empty

monitor.lock.check.interval

The amount of time to sleep between checking for the Montior ZooKeeper lock

Type: TIMEDURATION
+Zookeeper Mutable: no
+Default Value: 5s

monitor.port.client

The listening port for the monitor’s http service

Type: PORT
+Zookeeper Mutable: no
+Default Value: 50095

monitor.port.log4j

The listening port for the monitor’s log4j logging collection.

Type: PORT
+Zookeeper Mutable: no
+Default Value: 4560

14.3.9. trace.*

Properties in this category affect the behavior of distributed tracing.

trace.password

The password for the user used to store distributed traces

Type: STRING
+Zookeeper Mutable: no
+Default Value: secret

trace.port.client

The listening port for the trace server

Type: PORT
+Zookeeper Mutable: no
+Default Value: 12234

trace.table

The name of the table to store distributed traces

Type: STRING
+Zookeeper Mutable: no
+Default Value: trace

trace.token.type

An AuthenticationToken type supported by the authorizer

Type: CLASSNAME
+Zookeeper Mutable: no
+Default Value: org.apache.accumulo.core.client.security.tokens.PasswordToken

trace.user

The name of the user to store distributed traces

Type: STRING
+Zookeeper Mutable: no
+Default Value: root

14.3.10. trace.token.property.*

The prefix used to create a token for storing distributed traces. For each propetry required by trace.token.type, place this prefix in front of it.

14.3.11. table.*

Properties in this category affect tablet server treatment of tablets, but can be configured on a per-table basis. Setting these properties in the site file will override the default globally for all tables and not any specific table. However, both the default and the global setting can be overridden per table using the table operations API or in the shell, which sets the overridden value in zookeeper. Restarting accumulo tablet servers after setting these properties in the site file will cause the global setting to take effect. However, you must use the API or the shell to change properties in zookeeper that are set on a table.

table.balancer

This property can be set to allow the LoadBalanceByTable load balancer to change the called Load Balancer for this table

Type: STRING
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.server.master.balancer.DefaultLoadBalancer

table.bloom.enabled

Use bloom filters on this table.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: false

table.bloom.error.rate

Bloom filter error rate.

Type: FRACTION
+Zookeeper Mutable: yes
+Default Value: 0.5%

table.bloom.hash.type

The bloom filter hash type

Type: STRING
+Zookeeper Mutable: yes
+Default Value: murmur

table.bloom.key.functor

A function that can transform the key prior to insertion and check of bloom filter. org.apache.accumulo.core.file.keyfunctor.RowFunctor,,org.apache.accumulo.core.file.keyfunctor.ColumnFamilyFunctor, and org.apache.accumulo.core.file.keyfunctor.ColumnQualifierFunctor are allowable values. One can extend any of the above mentioned classes to perform specialized parsing of the key.

Type: CLASSNAME
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.core.file.keyfunctor.RowFunctor

table.bloom.load.threshold

This number of seeks that would actually use a bloom filter must occur before a file’s bloom filter is loaded. Set this to zero to initiate loading of bloom filters when a file is opened.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 1

table.bloom.size

Bloom filter size, as number of keys.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 1048576

table.cache.block.enable

Determines whether file block cache is enabled.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: false

table.cache.index.enable

Determines whether index cache is enabled.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: true

table.classpath.context

Per table classpath context

Type: STRING
+Zookeeper Mutable: yes
+Default Value: empty

table.compaction.major.everything.idle

After a tablet has been idle (no mutations) for this time period it may have all of its files compacted into one. There is no guarantee an idle tablet will be compacted. Compactions of idle tablets are only started when regular compactions are not running. Idle compactions only take place for tablets that have one or more files.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 1h

table.compaction.major.ratio

minimum ratio of total input size to maximum input file size for running a major compactionWhen adjusting this property you may want to also adjust table.file.max. Want to avoid the situation where only merging minor compactions occur.

Type: FRACTION
+Zookeeper Mutable: yes
+Default Value: 3

table.compaction.minor.idle

After a tablet has been idle (no mutations) for this time period it may have its in-memory map flushed to disk in a minor compaction. There is no guarantee an idle tablet will be compacted.

Type: TIMEDURATION
+Zookeeper Mutable: yes
+Default Value: 5m

table.compaction.minor.logs.threshold

When there are more than this many write-ahead logs against a tablet, it will be minor compacted. See comment for property tserver.memory.maps.max

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 3

table.failures.ignore

If you want queries for your table to hang or fail when data is missing from the system, then set this to false. When this set to true missing data will be reported but queries will still run possibly returning a subset of the data.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: false

table.file.blocksize

Overrides the hadoop dfs.block.size setting so that files have better query performance. The maximum value for this is 2147483647

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 0B

table.file.compress.blocksize

Similar to the hadoop io.seqfile.compress.blocksize setting, so that files have better query performance. The maximum value for this is 2147483647. (This setting is the size threshold prior to compression, and applies even compression is disabled.)

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 100K

table.file.compress.blocksize.index

Determines how large index blocks can be in files that support multilevel indexes. The maximum value for this is 2147483647. (This setting is the size threshold prior to compression, and applies even compression is disabled.)

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 128K

table.file.compress.type

One of gz,lzo,none

Type: STRING
+Zookeeper Mutable: yes
+Default Value: gz

table.file.max

Determines the max # of files each tablet in a table can have. When adjusting this property you may want to consider adjusting table.compaction.major.ratio also. Setting this property to 0 will make it default to tserver.scan.files.open.max-1, this will prevent a tablet from having more files than can be opened. Setting this property low may throttle ingest and increase query performance.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 15

table.file.replication

Determines how many replicas to keep of a tables' files in HDFS. When this value is LTE 0, HDFS defaults are used.

Type: COUNT
+Zookeeper Mutable: yes
+Default Value: 0

table.file.type

Change the type of file a table writes

Type: STRING
+Zookeeper Mutable: yes
+Default Value: rf

table.formatter

The Formatter class to apply on results in the shell

Type: STRING
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.core.util.format.DefaultFormatter

table.groups.enabled

A comma separated list of locality group names to enable for this table.

Type: STRING
+Zookeeper Mutable: yes
+Default Value: empty

table.interepreter

The ScanInterpreter class to apply on scan arguments in the shell

Type: STRING
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.core.util.interpret.DefaultScanInterpreter

table.majc.compaction.strategy

A customizable major compaction strategy.

Type: CLASSNAME
+Zookeeper Mutable: yes
+Default Value: org.apache.accumulo.tserver.compaction.DefaultCompactionStrategy

table.scan.max.memory

The maximum amount of memory that will be used to cache results of a client query/scan. Once this limit is reached, the buffered data is sent to the client.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 512K

table.security.scan.visibility.default

The security label that will be assumed at scan time if an entry does not have a visibility set. +Note: An empty security label is displayed as []. The scan results will show an empty visibility even if the visibility from this setting is applied to the entry. +CAUTION: If a particular key has an empty security label AND its table’s default visibility is also empty, access will ALWAYS be granted for users with permission to that table. Additionally, if this field is changed, all existing data with an empty visibility label will be interpreted with the new label on the next scan.

Type: STRING
+Zookeeper Mutable: yes
+Default Value: empty

table.split.threshold

When combined size of files exceeds this amount a tablet is split.

Type: MEMORY
+Zookeeper Mutable: yes
+Default Value: 1G

table.walog.enabled

Use the write-ahead log to prevent the loss of data.

Type: BOOLEAN
+Zookeeper Mutable: yes
+Default Value: true

14.3.12. table.constraint.*

Properties in this category are per-table properties that add constraints to a table. These properties start with the category prefix, followed by a number, and their values correspond to a fully qualified Java class that implements the Constraint interface. +For example: +table.constraint.1 = org.apache.accumulo.core.constraints.MyCustomConstraint +and: +table.constraint.2 = my.package.constraints.MySecondConstraint

14.3.13. table.iterator.*

Properties in this category specify iterators that are applied at various stages (scopes) of interaction with a table. These properties start with the category prefix, followed by a scope (minc, majc, scan, etc.), followed by a period, followed by a name, as in table.iterator.scan.vers, or table.iterator.scan.custom. The values for these properties are a number indicating the ordering in which it is applied, and a class name such as: + table.iterator.scan.vers = 10,org.apache.accumulo.core.iterators.VersioningIterator + These iterators can take options if additional properties are set that look like this property, but are suffixed with a period, followed by opt followed by another period, and a property name. +For example, table.iterator.minc.vers.opt.maxVersions = 3

14.3.14. table.group.*

Properties in this category are per-table properties that define locality groups in a table. These properties start with the category prefix, followed by a name, followed by a period, and followed by a property for that group. +For example table.group.group1=x,y,z sets the column families for a group called group1. Once configured, group1 can be enabled by adding it to the list of groups in the table.groups.enabled property. +Additional group options may be specified for a named group by setting table.group.<name>.opt.<key>=<value>.

14.3.15. table.majc.compaction.strategy.opts.*

Properties in this category are used to configure the compaction strategy.

14.3.16. general.vfs.context.classpath.*

Properties in this category are define a classpath. These properties start with the category prefix, followed by a context name. The value is a comma seperated list of URIs. Supports full regex on filename alone. For example, general.vfs.context.classpath.cx1=hdfs://nn1:9902/mylibdir/*.jar. You can enable post delegation for a context, which will load classes from the context first instead of the parent first. Do this by setting general.vfs.context.classpath.<name>.delegation=post, where <name> is your context nameIf delegation is not specified, it defaults to loading from parent classloader first.

14.4. Property Types

14.4.1. duration

A non-negative integer optionally followed by a unit of time (whitespace disallowed), as in 30s. +If no unit of time is specified, seconds are assumed. Valid units are ms, s, m, h for milliseconds, seconds, minutes, and hours. +Examples of valid durations are 600, 30s, 45m, 30000ms, 3d, and 1h. +Examples of invalid durations are 1w, 1h30m, 1s 200ms, ms, ', and 'a. +Unless otherwise stated, the max value for the duration represented in milliseconds is 9223372036854775807

14.4.2. date/time

A date/time string in the format: YYYYMMDDhhmmssTTT where TTT is the 3 character time zone

14.4.3. memory

A positive integer optionally followed by a unit of memory (whitespace disallowed), as in 2G. +If no unit is specified, bytes are assumed. Valid units are B, K, M, G, for bytes, kilobytes, megabytes, and gigabytes. +Examples of valid memories are 1024, 20B, 100K, 1500M, 2G. +Examples of invalid memories are 1M500K, 1M 2K, 1MB, 1.5G, 1,024K, ', and 'a. +Unless otherwise stated, the max value for the memory represented in bytes is 9223372036854775807

14.4.4. host list

A comma-separated list of hostnames or ip addresses, with optional port numbers. +Examples of valid host lists are localhost:2000,www.example.com,10.10.1.1:500 and localhost. +Examples of invalid host lists are ', ':1000, and localhost:80000

14.4.5. port

An positive integer in the range 1024-65535, not already in use or specified elsewhere in the configuration

14.4.6. count

A non-negative integer in the range of 0-2147483647

14.4.7. fraction/percentage

A floating point number that represents either a fraction or, if suffixed with the % character, a percentage. +Examples of valid fractions/percentages are 10, 1000%, 0.05, 5%, 0.2%, 0.0005. +Examples of invalid fractions/percentages are ', '10 percent, Hulk Hogan

14.4.8. path

A string that represents a filesystem path, which can be either relative or absolute to some directory. The filesystem depends on the property. The following environment variables will be substituted: [ACCUMULO_HOME, ACCUMULO_CONF_DIR]

14.4.9. absolute path

An absolute filesystem path. The filesystem depends on the property. This is the same as path, but enforces that its root is explicitly specified.

14.4.10. java class

A fully qualified java class name representing a class on the classpath. +An example is java.lang.String, rather than String

14.4.11. string

An arbitrary string of characters whose format is unspecified and interpreted based on the context of the property to which it applies.

14.4.12. boolean

Has a value of either true or false

14.4.13. uri

A valid URI

6.1. Locality Groups

14. Appendix A: Configuration Management

14.1. Configuration Overview

14.1.1. Zookeeper table properties

14.1.2. Zookeeper system properties

14.1.3. accumulo-site.xml

14.1.4. Default Values

14.2. Configuration in the Shell

14.3. Available Properties

14.3.1. rpc.*

rpc.javax.net.ssl.keyStore

rpc.javax.net.ssl.keyStorePassword

rpc.javax.net.ssl.keyStoreType

rpc.javax.net.ssl.trustStore

rpc.javax.net.ssl.trustStorePassword

rpc.javax.net.ssl.trustStoreType

rpc.useJsse

14.3.2. instance.*

instance.dfs.dir

instance.dfs.uri

instance.rpc.ssl.clientAuth

instance.rpc.ssl.enabled

instance.secret

instance.security.authenticator

instance.security.authorizor

instance.security.permissionHandler

instance.volumes

instance.volumes.replacements

instance.zookeeper.host

instance.zookeeper.timeout

14.3.3. general.*

general.classpaths

general.dynamic.classpaths

general.kerberos.keytab

general.kerberos.principal

general.rpc.timeout

general.server.message.size.max

general.server.simpletimer.threadpool.size

general.vfs.cache.dir

general.vfs.classpaths

14.3.4. master.*

master.bulk.retries

master.bulk.threadpool.size

master.bulk.timeout

master.fate.threadpool.size

master.lease.recovery.interval

master.port.client

master.recovery.delay

master.recovery.max.age

master.recovery.time.max

master.server.threadcheck.time

master.server.threads.minimum

master.tablet.balancer

master.walog.closer.implementation

14.3.5. tserver.*

tserver.archive.walogs

tserver.bloom.load.concurrent.max

tserver.bulk.assign.threads

tserver.bulk.process.threads

tserver.bulk.retry.max

tserver.bulk.timeout

tserver.cache.data.size

tserver.cache.index.size

tserver.client.timeout

tserver.compaction.major.concurrent.max

tserver.compaction.major.delay

tserver.compaction.major.thread.files.open.max

tserver.compaction.minor.concurrent.max

tserver.compaction.warn.time

tserver.default.blocksize

tserver.dir.memdump

tserver.files.open.idle

tserver.hold.time.max

tserver.memory.manager

tserver.memory.maps.max

tserver.memory.maps.native.enabled

tserver.metadata.readahead.concurrent.max

tserver.migrations.concurrent.max

tserver.monitor.fs

tserver.mutation.queue.max