Below are properties set in accumulo.properties or the Accumulo shell that configure Accumulo servers (i.e. tablet server, manager, etc). Properties labeled ‘Experimental’ should not be considered stable and have a higher risk of changing in the future.

Property Description
compaction.coordinator.* Experimental
Available since: 2.1.0
Properties in this category affect the behavior of the accumulo compaction coordinator server.
compaction.coordinator.compaction.finalizer.check.interval Experimental
Available since: 2.1.0
The interval at which to check for external compaction final state markers in the metadata table.
type: TIMEDURATION, zk mutable: no, default value: 60s
compaction.coordinator.compaction.finalizer.threads.maximum Experimental
Available since: 2.1.0
The maximum number of threads to use for notifying tablet servers that an external compaction has completed.
type: COUNT, zk mutable: no, default value: 5
compaction.coordinator.compactor.dead.check.interval Experimental
Available since: 2.1.0
The interval at which to check for dead compactors.
type: TIMEDURATION, zk mutable: no, default value: 5m
compaction.coordinator.message.size.max Experimental
Available since: 2.1.0
The maximum size of a message that can be sent to a tablet server.
type: BYTES, zk mutable: no, default value: 10M
compaction.coordinator.port.client Experimental
Available since: 2.1.0
The port used for handling Thrift client connections on the compaction coordinator server
type: PORT, zk mutable: no, default value: 9132
compaction.coordinator.port.search Experimental
Available since: 2.1.0
If the ports above are in use, search higher ports until one is available
type: BOOLEAN, zk mutable: no, default value: false
compaction.coordinator.threadcheck.time Experimental
Available since: 2.1.0
The time between adjustments of the server thread pool.
type: TIMEDURATION, zk mutable: no, default value: 1s
compaction.coordinator.threads.minimum Experimental
Available since: 2.1.0
The minimum number of threads to use to handle incoming requests.
type: COUNT, zk mutable: no, default value: 1
compaction.coordinator.threads.timeout Experimental
Available since: 2.1.0
The time after which incoming request threads terminate with no work available. Zero (0) will keep the threads alive indefinitely.
type: TIMEDURATION, zk mutable: no, default value: 0s
compaction.coordinator.tserver.check.interval Experimental
Available since: 2.1.0
The interval at which to check the tservers for external compactions.
type: TIMEDURATION, zk mutable: no, default value: 1m
compactor.* Experimental
Available since: 2.1.0
Properties in this category affect the behavior of the accumulo compactor server.
compactor.message.size.max Experimental
Available since: 2.1.0
The maximum size of a message that can be sent to a tablet server.
type: BYTES, zk mutable: no, default value: 10M
compactor.port.client Experimental
Available since: 2.1.0
The port used for handling client connections on the compactor servers
type: PORT, zk mutable: no, default value: 9133
compactor.port.search Experimental
Available since: 2.1.0
If the compactor.port.client is in use, search higher ports until one is available
type: BOOLEAN, zk mutable: no, default value: false
compactor.queue Experimental
Available since: 3.0.0
The queue for which this Compactor will perform compactions
type: STRING, zk mutable: no, default value: empty
compactor.threadcheck.time Experimental
Available since: 2.1.0
The time between adjustments of the server thread pool.
type: TIMEDURATION, zk mutable: no, default value: 1s
compactor.threads.minimum Experimental
Available since: 2.1.0
The minimum number of threads to use to handle incoming requests.
type: COUNT, zk mutable: no, default value: 1
compactor.threads.timeout Experimental
Available since: 2.1.0
The time after which incoming request threads terminate with no work available. Zero (0) will keep the threads alive indefinitely.
type: TIMEDURATION, zk mutable: no, default value: 0s
gc.* Available since: 1.3.5
Properties in this category affect the behavior of the accumulo garbage collector.
gc.candidate.batch.size Available since: 2.1.0
The batch size used for garbage collection.
type: BYTES, zk mutable: yes, default value: 8M
gc.cycle.delay Available since: 1.3.5
Time between garbage collection cycles. In each cycle, old RFiles or write-ahead logs no longer in use are removed from the filesystem.
type: TIMEDURATION, zk mutable: yes, default value: 5m
gc.cycle.start Available since: 1.3.5
Time to wait before attempting to garbage collect any old RFiles or write-ahead logs.
type: TIMEDURATION, zk mutable: yes, default value: 30s
gc.port.client Available since: 1.3.5
The listening port for the garbage collector’s monitor service
type: PORT, zk mutable: yes but requires restart of the gc, default value: 9998
gc.post.metadata.action Available since: 1.10.0
When the gc runs it can make a lot of changes to the metadata, on completion, to force the changes to be written to disk, the metadata and root tables can be flushed and possibly compacted. Legal values are: compact - which both flushes and compacts the metadata; flush - which flushes only (compactions may be triggered if required); or none
type: GC_POST_ACTION, zk mutable: yes, default value: flush
gc.safemode Available since: 2.1.0
Provides listing of files to be deleted but does not delete any files
type: BOOLEAN, zk mutable: yes, default value: false
gc.threads.delete Available since: 1.3.5
The number of threads used to delete RFiles and write-ahead logs
type: COUNT, zk mutable: yes, default value: 16
general.* Available since: 1.3.5
Properties in this category affect the behavior of accumulo overall, but do not have to be consistent throughout a cloud.
general.context.class.loader.factory Available since: 2.1.0
Name of classloader factory to be used to create classloaders for named contexts, such as per-table contexts set by table.class.loader.context.
type: CLASSNAME, zk mutable: no, default value: empty
general.custom.* Available since: 2.0.0
Prefix to be used for user defined system-wide properties. This may be particularly useful for system-wide configuration for various user-implementations of pluggable Accumulo features, such as the balancer or volume chooser.
general.delegation.token.lifetime Available since: 1.7.0
The length of time that delegation tokens and secret keys are valid
type: TIMEDURATION, zk mutable: no, default value: 7d
general.delegation.token.update.interval Available since: 1.7.0
The length of time between generation of new secret keys
type: TIMEDURATION, zk mutable: no, default value: 1d
general.kerberos.keytab Available since: 1.4.1
Path to the kerberos keytab to use. Leave blank if not using kerberoized hdfs
type: PATH, zk mutable: no, default value: empty
general.kerberos.principal Available since: 1.4.1
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, zk mutable: no, default value: empty
general.kerberos.renewal.period Available since: 1.6.5
The amount of time between attempts to perform Kerberos ticket renewals. This does not equate to how often tickets are actually renewed (which is performed at 80% of the ticket lifetime).
type: TIMEDURATION, zk mutable: no, default value: 30s
general.low.mem.detector.interval Available since: 3.0.0
The time interval between low memory checks
type: TIMEDURATION, zk mutable: no, default value: 5s
general.low.mem.detector.threshold Available since: 3.0.0
The LowMemoryDetector will report when free memory drops below this percentage of total memory
type: FRACTION, zk mutable: no, default value: 0.05
general.low.mem.protection.compaction.majc Available since: 3.0.0
Major compactions may be paused when the server is low on memory and this property is set to true. Enabling this property will incur a slight compaction performance penalty when the server is not low on memory
type: BOOLEAN, zk mutable: no, default value: false
general.low.mem.protection.compaction.minc Available since: 3.0.0
Minor compactions may be paused when the server is low on memory and this property is set to true. Enabling this property will incur a slight compaction performance penalty when the server is not low on memory
type: BOOLEAN, zk mutable: no, default value: false
general.low.mem.protection.scan Available since: 3.0.0
Scans may be paused or return results early when the server is low on memory and this property is set to true. Enabling this property will incur a slight scan performance penalty when the server is not low on memory
type: BOOLEAN, zk mutable: no, default value: false
general.max.scanner.retry.period Available since: 1.7.3
The maximum amount of time that a Scanner should wait before retrying a failed RPC
type: TIMEDURATION, zk mutable: no, default value: 5s
general.micrometer.enabled Available since: 2.1.0
Enables metrics functionality using Micrometer
type: BOOLEAN, zk mutable: no, default value: false
general.micrometer.factory Available since: 2.1.0
Name of class that implements MeterRegistryFactory
type: CLASSNAME, zk mutable: no, default value: empty
general.micrometer.jvm.metrics.enabled Available since: 2.1.0
Enables JVM metrics functionality using Micrometer
type: BOOLEAN, zk mutable: no, default value: false
general.opentelemetry.enabled Experimental
Available since: 2.1.0
Enables tracing functionality using OpenTelemetry (assuming OpenTelemetry is configured).
type: BOOLEAN, zk mutable: no, default value: false
general.process.bind.addr Available since: 3.0.0
The local IP address to which this server should bind for sending and receiving network traffic
type: STRING, zk mutable: no, default value: 0.0.0.0
general.rpc.server.type Experimental
Available since: 1.7.0
Type of Thrift server to instantiate, see org.apache.accumulo.server.rpc.ThriftServerType for more information. Only useful for benchmarking thrift servers
type: STRING, zk mutable: no, default value: empty
general.rpc.timeout Available since: 1.3.5
Time to wait on I/O for simple, short RPC calls
type: TIMEDURATION, zk mutable: no, default value: 120s
general.security.credential.provider.paths Available since: 1.6.1
Comma-separated list of paths to CredentialProviders
type: STRING, zk mutable: no, default value: empty
general.server.message.size.max Available since: 1.5.0
The maximum size of a message that can be sent to a server.
type: BYTES, zk mutable: no, default value: 1G
general.server.threadpool.size Available since: 2.1.0
The number of threads to use for server-internal scheduled tasks
type: COUNT, zk mutable: no, default value: 1
general.volume.chooser Experimental
Available since: 1.6.0
The class that will be used to select which volume will be used to create new files.
type: CLASSNAME, zk mutable: no, default value: org.apache.accumulo.core.spi.fs.RandomVolumeChooser
instance.* Available since: 1.3.5
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.crypto.opts.* Experimental
Available since: 2.0.0
Properties related to on-disk file encryption.
instance.crypto.opts.factory Experimental
Available since: 2.1.0
The class which provides crypto services for on-disk file encryption. The default does nothing. To enable encryption, replace this classname with an implementation of theorg.apache.accumulo.core.spi.crypto.CryptoFactory interface.
type: CLASSNAME, zk mutable: no, default value: org.apache.accumulo.core.spi.crypto.NoCryptoServiceFactory
instance.crypto.opts.sensitive.* Experimental
Available since: 2.0.0
Sensitive properties related to on-disk file encryption.
instance.rpc.sasl.allowed.host.impersonation Available since: 1.7.1
One-line configuration property controlling the network locations (hostnames) that are allowed to impersonate other users
type: STRING, zk mutable: no, default value: empty
instance.rpc.sasl.allowed.user.impersonation Available since: 1.7.1
One-line configuration property controlling what users are allowed to impersonate other users
type: STRING, zk mutable: no, default value: empty
instance.rpc.sasl.enabled Available since: 1.7.0
Configures Thrift RPCs to require SASL with GSSAPI which supports Kerberos authentication. Mutually exclusive with SSL RPC configuration.
type: BOOLEAN, zk mutable: no, default value: false
instance.rpc.ssl.clientAuth Available since: 1.6.0
Require clients to present certs signed by a trusted root
type: BOOLEAN, zk mutable: no, default value: false
instance.rpc.ssl.enabled Available since: 1.6.0
Use SSL for socket connections from clients and among accumulo services. Mutually exclusive with SASL RPC configuration.
type: BOOLEAN, zk mutable: no, default value: false
instance.secret Available since: 1.3.5
A secret unique to a given instance that all servers must know in order to communicate with one another. It should be changed prior to the initialization of Accumulo. To change it after Accumulo has been initialized, use the ChangeSecret tool and then update accumulo.properties everywhere. Before using the ChangeSecret tool, make sure Accumulo is not running and you are logged in as the user that controls Accumulo files in HDFS. To use the ChangeSecret tool, run the command: ./bin/accumulo org.apache.accumulo.server.util.ChangeSecret
type: STRING, zk mutable: no, default value: DEFAULT
instance.security.authenticator Experimental
Available since: 1.5.0
The authenticator class that accumulo will use to determine if a user has privilege to perform an action
type: CLASSNAME, zk mutable: no, default value: org.apache.accumulo.server.security.handler.ZKAuthenticator
instance.security.authorizor Experimental
Available since: 1.5.0
The authorizor class that accumulo will use to determine what labels a user has privilege to see
type: CLASSNAME, zk mutable: no, default value: org.apache.accumulo.server.security.handler.ZKAuthorizor
instance.security.permissionHandler Experimental
Available since: 1.5.0
The permission handler class that accumulo will use to determine if a user has privilege to perform an action
type: CLASSNAME, zk mutable: no, default value: org.apache.accumulo.server.security.handler.ZKPermHandler
instance.volume.config.* Available since: 2.1.1
Properties in this category are used to provide volume specific overrides to the general filesystem client configuration. Properties using this prefix should be in the form ‘instance.volume.config..=. An example: ‘instance.volume.config.hdfs://namespace-a:8020/accumulo.dfs.client.hedged.read.threadpool.size=10’. Note that when specifying property names that contain colons in the properties files that the colons need to be escaped with a backslash.
instance.volumes Available since: 1.6.0
A comma separated list of dfs uris to use. Files will be stored across these filesystems. In some situations, the first volume in this list may be treated differently, such as being preferred for writing out temporary files (for example, when creating a pre-split table). 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, zk mutable: no, default value: empty
instance.volumes.replacements Available since: 1.6.0
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 separated list of uri replacement pairs here if a namenode location changes. Each pair should be separated with a space. For example, if hdfs://nn1 was replaced 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, zk mutable: no, default value: empty
instance.volumes.upgrade.relative Available since: 2.1.0
The volume dfs uri containing relative tablet file paths. Relative paths may exist in the metadata from versions prior to 1.6. This property is only required if a relative path is detected during the upgrade process and will only be used once.
type: STRING, zk mutable: no, default value: empty
instance.zookeeper.host Available since: 1.3.5
Comma separated list of zookeeper servers
type: HOSTLIST, zk mutable: no, default value: localhost:2181
instance.zookeeper.timeout Available since: 1.3.5
Zookeeper session timeout; max value when represented as milliseconds should be no larger than 2147483647
type: TIMEDURATION, zk mutable: no, default value: 30s
manager.* Available since: 2.1.0
Properties in this category affect the behavior of the manager server.
manager.bulk.timeout Available since: 2.1.0 (formerly master.bulk.timeout since 1.4.3)
The time to wait for a tablet server to process a bulk import request
type: TIMEDURATION, zk mutable: yes, default value: 5m
manager.fate.metrics.min.update.interval Available since: 2.1.0 (formerly master.fate.metrics.min.update.interval since 1.9.3)
Limit calls from metric sinks to zookeeper to update interval
type: TIMEDURATION, zk mutable: yes, default value: 60s
manager.fate.threadpool.size Available since: 2.1.0 (formerly master.fate.threadpool.size since 1.4.3)
The number of threads used to run fault-tolerant executions (FATE). These are primarily table operations like merge.
type: COUNT, zk mutable: yes, default value: 4
manager.lease.recovery.interval Available since: 2.1.0 (formerly master.lease.recovery.interval since 1.5.0)
The amount of time to wait after requesting a write-ahead log to be recovered
type: TIMEDURATION, zk mutable: yes, default value: 5s
manager.metadata.suspendable Available since: 2.1.0 (formerly master.metadata.suspendable since 1.8.0)
Allow tablets for the accumulo.metadata table to be suspended via table.suspend.duration.
type: BOOLEAN, zk mutable: yes, default value: false
manager.port.client Available since: 2.1.0 (formerly master.port.client since 1.3.5)
The port used for handling client connections on the manager
type: PORT, zk mutable: yes but requires restart of the manager, default value: 9999
manager.recovery.delay Available since: 2.1.0 (formerly master.recovery.delay since 1.5.0)
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, zk mutable: yes, default value: 10s
manager.recovery.wal.cache.time Available since: 2.1.2
Amount of time that the existence of recovery write-ahead logs is cached.
type: TIMEDURATION, zk mutable: yes but requires restart of the manager, default value: 15s
manager.rename.threadpool.size Available since: 2.1.0
The number of threads to use when renaming user files during table import or bulk ingest.
type: COUNT, zk mutable: yes, default value: 20
manager.server.threadcheck.time Available since: 2.1.0 (formerly master.server.threadcheck.time since 1.4.0)
The time between adjustments of the server thread pool.
type: TIMEDURATION, zk mutable: yes, default value: 1s
manager.server.threads.minimum Available since: 2.1.0 (formerly master.server.threads.minimum since 1.4.0)
The minimum number of threads to use to handle incoming requests.
type: COUNT, zk mutable: yes, default value: 20
manager.server.threads.timeout Available since: 2.1.0
The time after which incoming request threads terminate with no work available. Zero (0) will keep the threads alive indefinitely.
type: TIMEDURATION, zk mutable: yes, default value: 0s
manager.startup.tserver.avail.max.wait Available since: 2.1.0 (formerly master.startup.tserver.avail.max.wait since 1.10.0)
Maximum time manager will wait for tserver available threshold to be reached before continuing. When set to 0 or less, will block indefinitely. Default is 0 to block indefinitely. Only valid when tserver available threshold is set greater than 0. Added with version 1.10
type: TIMEDURATION, zk mutable: yes, default value: 0
manager.startup.tserver.avail.min.count Available since: 2.1.0 (formerly master.startup.tserver.avail.min.count since 1.10.0)
Minimum number of tservers that need to be registered before manager will start tablet assignment - checked at manager initialization, when manager gets lock. When set to 0 or less, no blocking occurs. Default is 0 (disabled) to keep original behaviour. Added with version 1.10
type: COUNT, zk mutable: yes, default value: 0
manager.status.threadpool.size Available since: 2.1.0 (formerly master.status.threadpool.size since 1.8.0)
The number of threads to use when fetching the tablet server status for balancing. Zero indicates an unlimited number of threads will be used.
type: COUNT, zk mutable: yes, default value: 0
manager.tablet.balancer Available since: 2.1.0 (formerly master.tablet.balancer since 1.3.5)
The balancer class that accumulo will use to make tablet assignment and migration decisions.
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.core.spi.balancer.TableLoadBalancer
manager.tablet.watcher.interval Available since: 2.1.2
Time to wait between scanning tablet states to identify tablets that need to be assigned, un-assigned, migrated, etc.
type: TIMEDURATION, zk mutable: yes, default value: 60s
manager.wal.closer.implementation Available since: 2.1.0
A class that implements a mechanism to steal write access to a write-ahead log
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.server.manager.recovery.HadoopLogCloser
monitor.* Available since: 1.3.5
Properties in this category affect the behavior of the monitor web server.
monitor.lock.check.interval Available since: 1.5.1
The amount of time to sleep between checking for the Monitor ZooKeeper lock
type: TIMEDURATION, zk mutable: no, default value: 5s
monitor.port.client Available since: 1.3.5
The listening port for the monitor’s http service
type: PORT, zk mutable: no, default value: 9995
monitor.resources.external Available since: 2.0.0
A JSON Map of Strings. Each String should be an HTML tag of an external resource (JS or CSS) to be imported by the Monitor. Be sure to wrap with CDATA tags. If this value is set, all of the external resources in the <head> tag of the Monitor will be replaced with the tags set here. Be sure the jquery tag is first since other scripts will depend on it. The resources that are used by default can be seen in accumulo/server/monitor/src/main/resources/templates/default.ftl
type: STRING, zk mutable: no, default value: empty
monitor.ssl.exclude.ciphers Available since: 1.6.1
A comma-separated list of disallowed SSL Ciphers, see monitor.ssl.include.ciphers to allow ciphers
type: STRING, zk mutable: no, default value: empty
monitor.ssl.include.ciphers Available since: 1.6.1
A comma-separated list of allows SSL Ciphers, see monitor.ssl.exclude.ciphers to disallow ciphers
type: STRING, zk mutable: no, default value: empty
monitor.ssl.include.protocols Available since: 1.5.3
A comma-separate list of allowed SSL protocols
type: STRING, zk mutable: no, default value: TLSv1.2
monitor.ssl.keyPassword Available since: 1.9.3
Optional: the password for the private key in the keyStore. When not provided, this defaults to the keystore password.
type: STRING, zk mutable: no, default value: empty
monitor.ssl.keyStore Available since: 1.5.0
The keystore for enabling monitor SSL.
type: PATH, zk mutable: no, default value: empty
monitor.ssl.keyStorePassword Available since: 1.5.0
The keystore password for enabling monitor SSL.
type: STRING, zk mutable: no, default value: empty
monitor.ssl.keyStoreType Available since: 1.7.0
Type of SSL keystore
type: STRING, zk mutable: no, default value: jks
monitor.ssl.trustStore Available since: 1.5.0
The truststore for enabling monitor SSL.
type: PATH, zk mutable: no, default value: empty
monitor.ssl.trustStorePassword Available since: 1.5.0
The truststore password for enabling monitor SSL.
type: STRING, zk mutable: no, default value: empty
monitor.ssl.trustStoreType Available since: 1.7.0
Type of SSL truststore
type: STRING, zk mutable: no, default value: jks
rpc.* Available since: 1.6.0
Properties in this category related to the configuration of SSL keys for RPC. See also instance.ssl.enabled
rpc.javax.net.ssl.keyStore Available since: 1.6.0
Path of the keystore file for the server’s private SSL key
type: PATH, zk mutable: no, default value: empty
rpc.javax.net.ssl.keyStorePassword Available since: 1.6.0
Password used to encrypt the SSL private keystore. Leave blank to use the Accumulo instance secret
type: STRING, zk mutable: no, default value: empty
rpc.javax.net.ssl.keyStoreType Available since: 1.6.0
Type of SSL keystore
type: STRING, zk mutable: no, default value: jks
rpc.javax.net.ssl.trustStore Available since: 1.6.0
Path of the truststore file for the root cert
type: PATH, zk mutable: no, default value: empty
rpc.javax.net.ssl.trustStorePassword Available since: 1.6.0
Password used to encrypt the SSL truststore. Leave blank to use no password
type: STRING, zk mutable: no, default value: empty
rpc.javax.net.ssl.trustStoreType Available since: 1.6.0
Type of SSL truststore
type: STRING, zk mutable: no, default value: jks
rpc.sasl.qop Available since: 1.7.0
The quality of protection to be used with SASL. Valid values are ‘auth’, ‘auth-int’, and ‘auth-conf’
type: STRING, zk mutable: no, default value: auth
rpc.ssl.cipher.suites Available since: 1.6.1
Comma separated list of cipher suites that can be used by accepted connections
type: STRING, zk mutable: no, default value: empty
rpc.ssl.client.protocol Available since: 1.6.2
The protocol used to connect to a secure server, must be in the list of enabled protocols on the server side (rpc.ssl.server.enabled.protocols)
type: STRING, zk mutable: no, default value: TLSv1.2
rpc.ssl.server.enabled.protocols Available since: 1.6.2
Comma separated list of protocols that can be used to accept connections
type: STRING, zk mutable: no, default value: TLSv1.2
rpc.useJsse Available since: 1.6.0
Use JSSE system properties to configure SSL rather than the rpc.javax.net.ssl. Accumulo properties
type: BOOLEAN, zk mutable: no, *default value: false
sserver.* Experimental
Available since: 2.1.0
Properties in this category affect the behavior of the scan servers
sserver.cache.data.size Experimental
Available since: 2.1.0
Specifies the size of the cache for RFile data blocks on each scan server.
type: MEMORY, zk mutable: no, default value: 10%
sserver.cache.index.size Experimental
Available since: 2.1.0
Specifies the size of the cache for RFile index blocks on each scan server.
type: MEMORY, zk mutable: no, default value: 25%
sserver.cache.metadata.expiration Experimental
Available since: 2.1.0
The time after which cached tablet metadata will be refreshed.
type: TIMEDURATION, zk mutable: no, default value: 5m
sserver.cache.summary.size Experimental
Available since: 2.1.0
Specifies the size of the cache for summary data on each scan server.
type: MEMORY, zk mutable: no, default value: 10%
sserver.default.blocksize Experimental
Available since: 2.1.0
Specifies a default blocksize for the scan server caches
type: BYTES, zk mutable: no, default value: 1M
sserver.group Experimental
Available since: 3.0.0
Optional group name that will be made available to the ScanServerSelector client plugin. Groups support at least two use cases: dedicating resources to scans and/or using different hardware for scans.
type: STRING, zk mutable: no, default value: default
sserver.port.client Experimental
Available since: 2.1.0
The port used for handling client connections on the tablet servers
type: PORT, zk mutable: no, default value: 9996
sserver.port.search Experimental
Available since: 2.1.0
if the ports above are in use, search higher ports until one is available
type: BOOLEAN, zk mutable: no, default value: true
sserver.scan.executors.* Experimental
Available since: 2.1.0
Prefix for defining executors to service scans. See scan executors for an overview of why and how to use this property. For each executor the number of threads, thread priority, and an optional prioritizer can be configured. To configure a new executor, set sserver.scan.executors.<name>.threads=<number>. Optionally, can also set sserver.scan.executors.<name>.priority=<number 1 to 10>, sserver.scan.executors.<name>.prioritizer=<class name>, and sserver.scan.executors.<name>.prioritizer.opts.<key>=<value>
sserver.scan.executors.default.prioritizer Experimental
Available since: 2.1.0
Prioritizer for the default scan executor. Defaults to none which results in FIFO priority. Set to a class that implements org.apache.accumulo.core.spi.scan.ScanPrioritizer to configure one.
type: STRING, zk mutable: no, default value: empty
sserver.scan.executors.default.threads Experimental
Available since: 2.1.0
The number of threads for the scan executor that tables use by default.
type: COUNT, zk mutable: no, default value: 16
sserver.scan.executors.meta.threads Experimental
Available since: 2.1.0
The number of threads for the metadata table scan executor.
type: COUNT, zk mutable: no, default value: 8
sserver.scan.reference.expiration Experimental
Available since: 2.1.0
The amount of time a scan reference is unused before its deleted from metadata table
type: TIMEDURATION, zk mutable: no, default value: 5m
sserver.server.message.size.max Experimental
Available since: 2.1.0
The maximum size of a message that can be sent to a scan server.
type: BYTES, zk mutable: no, default value: 1G
sserver.server.threadcheck.time Experimental
Available since: 2.1.0
The time between adjustments of the thrift server thread pool.
type: TIMEDURATION, zk mutable: no, default value: 1s
sserver.server.threads.minimum Experimental
Available since: 2.1.0
The minimum number of threads to use to handle incoming requests.
type: COUNT, zk mutable: no, default value: 2
sserver.server.threads.timeout Experimental
Available since: 2.1.0
The time after which incoming request threads terminate with no work available. Zero (0) will keep the threads alive indefinitely.
type: TIMEDURATION, zk mutable: no, default value: 0s
table.* Available since: 1.3.5
Properties in this category affect tablet server treatment of tablets, but can be configured on a per-table basis. Setting these properties in accumulo.properties 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 accumulo.properties 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 Available since: 1.3.5
This property can be set to allow the LoadBalanceByTable load balancer to change the called Load Balancer for this table
type: STRING, zk mutable: yes, default value: org.apache.accumulo.core.spi.balancer.SimpleLoadBalancer
table.bloom.enabled Available since: 1.3.5
Use bloom filters on this table.
type: BOOLEAN, zk mutable: yes, default value: false
table.bloom.error.rate Available since: 1.3.5
Bloom filter error rate.
type: FRACTION, zk mutable: yes, default value: 0.5%
table.bloom.hash.type Available since: 1.3.5
The bloom filter hash type
type: STRING, zk mutable: yes, default value: murmur
table.bloom.key.functor Available since: 1.3.5
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, zk mutable: yes, default value: org.apache.accumulo.core.file.keyfunctor.RowFunctor
table.bloom.load.threshold Available since: 1.3.5
This number of seeks that would actually use a bloom filter must occur before a RFile’s bloom filter is loaded. Set this to zero to initiate loading of bloom filters when a RFile is opened.
type: COUNT, zk mutable: yes, default value: 1
table.bloom.size Available since: 1.3.5
Bloom filter size, as number of keys.
type: COUNT, zk mutable: yes, default value: 1048576
table.bulk.max.tablets Available since: 2.1.0
The maximum number of tablets allowed for one bulk import file. Value of 0 is Unlimited. This property is only enforced in the new bulk import API
type: COUNT, zk mutable: yes, default value: 0
table.cache.block.enable Available since: 1.3.5
Determines whether data block cache is enabled for a table.
type: BOOLEAN, zk mutable: yes, default value: false
table.cache.index.enable Available since: 1.3.5
Determines whether index block cache is enabled for a table.
type: BOOLEAN, zk mutable: yes, default value: true
table.class.loader.context Available since: 2.1.0
The context to use for loading per-table resources, such as iterators from the configured factory in general.context.class.loader.factory.
type: STRING, zk mutable: yes, default value: empty
table.compaction.configurer Available since: 2.1.0
A plugin that can dynamically configure compaction output files based on input files.
type: CLASSNAME, zk mutable: yes, default value: empty
table.compaction.configurer.opts.* Available since: 2.1.0
Options for the table compaction configuror
table.compaction.dispatcher Available since: 2.1.0
A configurable dispatcher that decides what compaction service a table should use.
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.core.spi.compaction.SimpleCompactionDispatcher
table.compaction.dispatcher.opts.* Available since: 2.1.0
Options for the table compaction dispatcher
table.compaction.major.output.drop.cache Available since: 2.1.1
Setting this property to true will callFSDataOutputStream.setDropBehind(true) on the major compaction output stream.
type: BOOLEAN, zk mutable: yes, default value: false
table.compaction.major.ratio Available since: 1.3.5
Minimum ratio of total input size to maximum input RFile size for running a major compaction.
type: FRACTION, zk mutable: yes, default value: 3
table.compaction.minor.idle Available since: 1.3.5
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, zk mutable: yes, default value: 5m
table.compaction.minor.output.drop.cache Available since: 2.1.1
Setting this property to true will callFSDataOutputStream.setDropBehind(true) on the minor compaction output stream.
type: BOOLEAN, zk mutable: yes, default value: false
table.compaction.selection.expiration.ms Available since: 2.1.0
User compactions select files and are then queued for compaction, preventing these files from being used in system compactions. This timeout allows system compactions to cancel the hold queued user compactions have on files, when its queued for more than the specified time. If a system compaction cancels a hold and runs, then the user compaction can reselect and hold files after the system compaction runs.
type: TIMEDURATION, zk mutable: yes, default value: 2m
table.compaction.selector Available since: 2.1.0
A configurable selector for a table that can periodically select file for mandatory compaction, even if the files do not meet the compaction ratio.
type: CLASSNAME, zk mutable: yes, default value: empty
table.compaction.selector.opts.* Available since: 2.1.0
Options for the table compaction dispatcher
table.constraint.* Available since: 1.3.5
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
table.crypto.opts.* Experimental
Available since: 2.1.0
Properties related to on-disk file encryption.
table.crypto.opts.sensitive.* Experimental
Available since: 2.1.0
Sensitive properties related to on-disk file encryption.
table.custom.* Available since: 1.7.0
Prefix to be used for user defined arbitrary properties.
table.delete.behavior Experimental
Available since: 2.0.0
This determines what action to take when a delete marker is seen. Valid values are process and fail with process being the default. When set to process, deletes will suppress data. When set to fail, any deletes seen will cause an exception. The purpose of fail is to support tables that never delete data and need fast seeks within the timestamp range of a column. When setting this to fail, also consider configuring the org.apache.accumulo.core.data.constraints.NoDeleteConstraint constraint.
type: STRING, zk mutable: yes, default value: process
table.durability Available since: 1.7.0
The durability used to write to the write-ahead log. Legal values are: none, which skips the write-ahead log; log, which sends the data to the write-ahead log, but does nothing to make it durable; flush, which pushes data to the file system; and sync, which ensures the data is written to disk.
type: DURABILITY, zk mutable: yes, default value: sync
table.failures.ignore Available since: 1.3.5
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, zk mutable: yes, default value: false
table.file.blocksize Available since: 1.3.5
The HDFS block size used when writing RFiles. When set to 0B, the value/defaults of HDFS property ‘dfs.block.size’ will be used.
type: BYTES, zk mutable: yes, default value: 0B
table.file.compress.blocksize Available since: 1.3.5
The maximum size of data blocks in RFiles before they are compressed and written.
type: BYTES, zk mutable: yes, default value: 100k
table.file.compress.blocksize.index Available since: 1.4.0
The maximum size of index blocks in RFiles before they are compressed and written.
type: BYTES, zk mutable: yes, default value: 128k
table.file.compress.type Available since: 1.3.5
Compression algorithm used on index and data blocks before they are written. Possible values: zstd, gz, snappy, bzip2, lzo, lz4, none
type: STRING, zk mutable: yes, default value: gz
table.file.max Available since: 1.4.0
The maximum number of RFiles 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 RFiles than can be opened. Setting this property low may throttle ingest and increase query performance.
type: COUNT, zk mutable: yes, default value: 15
table.file.replication Available since: 1.3.5
The number of replicas for a table’s RFiles in HDFS. When set to 0, HDFS defaults are used.
type: COUNT, zk mutable: yes, default value: 0
table.file.summary.maxSize Available since: 2.0.0
The maximum size summary that will be stored. The number of RFiles that had summary data exceeding this threshold is reported by Summary.getFileStatistics().getLarge(). When adjusting this consider the expected number RFiles with summaries on each tablet server and the summary cache size.
type: BYTES, zk mutable: yes, default value: 256k
table.file.type Available since: 1.3.5
Change the type of file a table writes
type: FILENAME_EXT, zk mutable: yes, default value: rf
table.formatter Available since: 1.4.0
The Formatter class to apply on results in the shell
type: STRING, zk mutable: yes, default value: org.apache.accumulo.core.util.format.DefaultFormatter
table.group.* Available since: 1.3.5
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>.
table.groups.enabled Available since: 1.3.5
A comma separated list of locality group names to enable for this table.
type: STRING, zk mutable: yes, default value: empty
table.iterator.* Available since: 1.3.5
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
table.iterator.majc.* Available since: 1.5.2
Convenience prefix to find options for the majc iterator scope
table.iterator.minc.* Available since: 1.5.2
Convenience prefix to find options for the minc iterator scope
table.iterator.scan.* Available since: 1.5.2
Convenience prefix to find options for the scan iterator scope
table.sampler Available since: 1.8.0
The name of a class that implements org.apache.accumulo.core.Sampler. Setting this option enables storing a sample of data which can be scanned. Always having a current sample can useful for query optimization and data comprehension. After enabling sampling for an existing table, a compaction is needed to compute the sample for existing data. The compact command in the shell has an option to only compact RFiles without sample data.
type: CLASSNAME, zk mutable: yes, default value: empty
table.sampler.opt.* Available since: 1.8.0
The property is used to set options for a sampler. If a sample had two options like hasher and modulous, then the two properties table.sampler.opt.hasher=${hash algorithm} and table.sampler.opt.modulous=${mod} would be set.
table.scan.dispatcher Available since: 2.0.0
This class is used to dynamically dispatch scans to configured scan executors. Configured classes must implement org.apache.accumulo.core.spi.scan.ScanDispatcher See scan executors for an overview of why and how to use this property. This property is ignored for the root and metadata table. The metadata table always dispatches to a scan executor named meta.
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.core.spi.scan.SimpleScanDispatcher
table.scan.dispatcher.opts.* Available since: 2.0.0
Options for the table scan dispatcher
table.scan.max.memory Available since: 1.3.5
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: BYTES, zk mutable: yes, default value: 512k
table.security.scan.visibility.default Available since: 1.3.5
The security label that will be assumed at scan time if an entry does not have a visibility expression.
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, zk mutable: yes, default value: empty
table.split.endrow.size.max Available since: 1.7.0
Maximum size of end row
type: BYTES, zk mutable: yes, default value: 10k
table.split.threshold Available since: 1.3.5
A tablet is split when the combined size of RFiles exceeds this amount.
type: BYTES, zk mutable: yes, default value: 1G
table.summarizer.* Available since: 2.0.0
Prefix for configuring summarizers for a table. Using this prefix multiple summarizers can be configured with options for each one. Each summarizer configured should have a unique id, this id can be anything. To add a summarizer set table.summarizer.<unique id>=<summarizer class name>. If the summarizer has options, then for each option set table.summarizer.<unique id>.opt.<key>=<value>.
table.suspend.duration Available since: 1.8.0
For tablets belonging to this table: When a tablet server dies, allow the tablet server this duration to revive before reassigning its tablets to other tablet servers.
type: TIMEDURATION, zk mutable: yes, default value: 0s
tserver.* Available since: 1.3.5
Properties in this category affect the behavior of the tablet servers
tserver.assignment.concurrent.max Available since: 1.7.0
The number of threads available to load tablets. Recoveries are still performed serially.
type: COUNT, zk mutable: yes, default value: 2
tserver.assignment.duration.warning Available since: 1.6.2
The amount of time an assignment can run before the server will print a warning along with the current stack trace. Meant to help debug stuck assignments
type: TIMEDURATION, zk mutable: yes, default value: 10m
tserver.bloom.load.concurrent.max Available since: 1.3.5
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, zk mutable: yes, default value: 4
tserver.cache.data.size Available since: 1.3.5
Specifies the size of the cache for RFile data blocks.
type: MEMORY, zk mutable: yes but requires restart of the tserver, default value: 10%
tserver.cache.index.size Available since: 1.3.5
Specifies the size of the cache for RFile index blocks.
type: MEMORY, zk mutable: yes but requires restart of the tserver, default value: 25%
tserver.cache.manager.class Available since: 2.0.0
Specifies the class name of the block cache factory implementation. Alternative implementation is org.apache.accumulo.core.file.blockfile.cache.tinylfu.TinyLfuBlockCacheManager
type: STRING, zk mutable: yes but requires restart of the tserver, default value: org.apache.accumulo.core.file.blockfile.cache.lru.LruBlockCacheManager
tserver.cache.summary.size Available since: 2.0.0
Specifies the size of the cache for summary data on each tablet server.
type: MEMORY, zk mutable: yes but requires restart of the tserver, default value: 10%
tserver.client.timeout Available since: 1.3.5
Time to wait for clients to continue scans before closing a session.
type: TIMEDURATION, zk mutable: yes, default value: 3s
tserver.compaction.major.delay Available since: 1.3.5
Time a tablet server will sleep between checking which tablets need compaction.
type: TIMEDURATION, zk mutable: yes, default value: 30s
tserver.compaction.major.service.* Available since: 2.1.0
Prefix for compaction services.
tserver.compaction.major.service.default.planner Available since: 2.1.0
Planner for default compaction service.
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner
tserver.compaction.major.service.default.planner.opts.executors Available since: 2.1.0
See org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner
type: STRING, zk mutable: yes, default value: [{"name":"small","type":"internal","maxSize":"32M","numThreads":2},{"name":"medium","type":"internal","maxSize":"128M","numThreads":2},{"name":"large","type":"internal","numThreads":2}]
tserver.compaction.major.service.default.planner.opts.maxOpen Available since: 2.1.0
The maximum number of files a compaction will open
type: COUNT, zk mutable: yes, default value: 10
tserver.compaction.major.service.default.rate.limit Available since: 2.1.0
Maximum number of bytes to read or write per second over all major compactions in this compaction service, or 0B for unlimited.
type: BYTES, zk mutable: yes, default value: 0B
tserver.compaction.major.service.meta.planner Available since: 2.1.0
Compaction planner for metadata table
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner
tserver.compaction.major.service.meta.planner.opts.executors Available since: 2.1.0
See org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner
type: STRING, zk mutable: yes, default value: [{"name":"small","type":"internal","maxSize":"32M","numThreads":2},{"name":"huge","type":"internal","numThreads":2}]
tserver.compaction.major.service.meta.planner.opts.maxOpen Available since: 2.1.0
The maximum number of files a compaction will open
type: COUNT, zk mutable: yes, default value: 30
tserver.compaction.major.service.meta.rate.limit Available since: 2.1.0
Maximum number of bytes to read or write per second over all major compactions in this compaction service, or 0B for unlimited.
type: BYTES, zk mutable: yes, default value: 0B
tserver.compaction.major.service.root.planner Available since: 2.1.0
Compaction planner for root tablet service
type: CLASSNAME, zk mutable: yes, default value: org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner
tserver.compaction.major.service.root.planner.opts.executors Available since: 2.1.0
See org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner
type: STRING, zk mutable: yes, default value: [{"name":"small","type":"internal","maxSize":"32M","numThreads":1},{"name":"huge","type":"internal","numThreads":1}]
tserver.compaction.major.service.root.planner.opts.maxOpen Available since: 2.1.0
The maximum number of files a compaction will open
type: COUNT, zk mutable: yes, default value: 30
tserver.compaction.major.service.root.rate.limit Available since: 2.1.0
Maximum number of bytes to read or write per second over all major compactions in this compaction service, or 0B for unlimited.
type: BYTES, zk mutable: yes, default value: 0B
tserver.compaction.minor.concurrent.max Available since: 1.3.5
The maximum number of concurrent minor compactions for a tablet server
type: COUNT, zk mutable: yes, default value: 4
tserver.compaction.warn.time Available since: 1.6.0
When a compaction has not made progress for this time period, a warning will be logged
type: TIMEDURATION, zk mutable: yes, default value: 10m
tserver.default.blocksize Available since: 1.3.5
Specifies a default blocksize for the tserver caches
type: BYTES, zk mutable: yes, default value: 1M
tserver.dir.memdump Available since: 1.3.5
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, zk mutable: yes, default value: /tmp
tserver.files.open.idle Available since: 1.3.5
Tablet servers leave previously used RFiles open for future queries. This setting determines how much time an unused RFile should be kept open until it is closed.
type: TIMEDURATION, zk mutable: yes, default value: 1m
tserver.health.check.interval Available since: 2.1.0
The time between tablet server health checks.
type: TIMEDURATION, zk mutable: yes, default value: 30m
tserver.hold.time.max Available since: 1.4.0
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, zk mutable: yes, default value: 5m
tserver.last.location.mode Available since: 2.1.1
Describes how the system will record the ‘last’ location for tablets, which can be used for assigning them when a cluster restarts. If ‘compaction’ is the mode, then the system will record the location where the tablet’s most recent compaction occurred. If ‘assignment’ is the mode, then the most recently assigned location will be recorded. The manager.startup.tserver properties might also need to be set to ensure the tserver is available before tablets are initially assigned if the ‘last’ location is to be used.
type: LAST_LOCATION_MODE, zk mutable: yes, default value: compaction
tserver.log.busy.tablets.count Available since: 1.10.0
Number of busiest tablets to log. Logged at interval controlled by tserver.log.busy.tablets.interval. If <= 0, logging of busy tablets is disabled
type: COUNT, zk mutable: yes, default value: 0
tserver.log.busy.tablets.interval Available since: 1.10.0
Time interval between logging out busy tablets information.
type: TIMEDURATION, zk mutable: yes, default value: 1h
tserver.memory.maps.max Available since: 1.3.5
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.wal.max.size. Ensure that table.compaction.minor.logs.threshold tserver.wal.max.size >= this property.
type: MEMORY, zk mutable: yes, *default value: 33%
tserver.memory.maps.native.enabled Available since: 1.3.5
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, zk mutable: yes but requires restart of the tserver, default value: true
tserver.migrations.concurrent.max Available since: 1.3.5
The maximum number of concurrent tablet migrations for a tablet server
type: COUNT, zk mutable: yes, default value: 1
tserver.port.client Available since: 1.3.5
The port used for handling client connections on the tablet servers
type: PORT, zk mutable: yes but requires restart of the tserver, default value: 9997
tserver.port.search Available since: 1.3.5
if the ports above are in use, search higher ports until one is available
type: BOOLEAN, zk mutable: yes, default value: false
tserver.scan.executors.* Available since: 2.0.0
Prefix for defining executors to service scans. See scan executors for an overview of why and how to use this property. For each executor the number of threads, thread priority, and an optional prioritizer can be configured. To configure a new executor, set tserver.scan.executors.<name>.threads=<number>. Optionally, can also set tserver.scan.executors.<name>.priority=<number 1 to 10>, tserver.scan.executors.<name>.prioritizer=<class name>, and tserver.scan.executors.<name>.prioritizer.opts.<key>=<value>
tserver.scan.executors.default.prioritizer Available since: 2.0.0
Prioritizer for the default scan executor. Defaults to none which results in FIFO priority. Set to a class that implements org.apache.accumulo.core.spi.scan.ScanPrioritizer to configure one.
type: STRING, zk mutable: yes, default value: empty
tserver.scan.executors.default.threads Available since: 2.0.0
The number of threads for the scan executor that tables use by default.
type: COUNT, zk mutable: yes, default value: 16
tserver.scan.executors.meta.threads Available since: 2.0.0
The number of threads for the metadata table scan executor.
type: COUNT, zk mutable: yes, default value: 8
tserver.scan.files.open.max Available since: 1.4.0
Maximum total RFiles that all tablets in a tablet server can open for scans.
type: COUNT, zk mutable: yes but requires restart of the tserver, default value: 100
tserver.scan.results.max.timeout Available since: 2.1.0
Max time for the thrift client handler to wait for scan results before timing out.
type: TIMEDURATION, zk mutable: yes, default value: 1s
tserver.server.message.size.max Available since: 1.6.0
The maximum size of a message that can be sent to a tablet server.
type: BYTES, zk mutable: yes, default value: 1G
tserver.server.threadcheck.time Available since: 1.4.0
The time between adjustments of the server thread pool.
type: TIMEDURATION, zk mutable: yes, default value: 1s
tserver.server.threads.minimum Available since: 1.4.0
The minimum number of threads to use to handle incoming requests.
type: COUNT, zk mutable: yes, default value: 20
tserver.server.threads.timeout Available since: 2.1.0
The time after which incoming request threads terminate with no work available. Zero (0) will keep the threads alive indefinitely.
type: TIMEDURATION, zk mutable: yes, default value: 0s
tserver.session.idle.max Available since: 1.3.5
When a tablet server’s SimpleTimer thread triggers to check idle sessions, this configurable option will be used to evaluate scan sessions to determine if they can be closed due to inactivity
type: TIMEDURATION, zk mutable: yes, default value: 1m
tserver.session.update.idle.max Available since: 1.6.5
When a tablet server’s SimpleTimer thread triggers to check idle sessions, this configurable option will be used to evaluate update sessions to determine if they can be closed due to inactivity
type: TIMEDURATION, zk mutable: yes, default value: 1m
tserver.slow.filepermit.time Available since: 1.9.3
If a thread blocks more than this period of time waiting to get file permits, debugging information will be written.
type: TIMEDURATION, zk mutable: yes, default value: 100ms
tserver.slow.flush.time Available since: 1.8.0
If a flush to the write-ahead log takes longer than this period of time, debugging information will written, and may result in a log rollover.
type: TIMEDURATION, zk mutable: yes, default value: 100ms
tserver.summary.partition.threads Available since: 2.0.0
Summary data must be retrieved from RFiles. For a large number of RFiles, the files are broken into partitions of 100k files. This setting determines how many of these groups of 100k RFiles will be processed concurrently.
type: COUNT, zk mutable: yes, default value: 10
tserver.summary.remote.threads Available since: 2.0.0
For a partitioned group of 100k RFiles, those files are grouped by tablet server. Then a remote tablet server is asked to gather summary data. This setting determines how many concurrent request are made per partition.
type: COUNT, zk mutable: yes, default value: 128
tserver.summary.retrieval.threads Available since: 2.0.0
The number of threads on each tablet server available to retrieve summary data, that is not currently in cache, from RFiles.
type: COUNT, zk mutable: yes, default value: 10
tserver.tablet.split.midpoint.files.max Available since: 1.3.5
To find a tablets split points, all RFiles are opened and their indexes are read. This setting determines how many RFiles can be opened at once. When there are more RFiles than this setting multiple passes must be made, which is slower. However opening too many RFiles at once can cause problems.
type: COUNT, zk mutable: yes, default value: 300
tserver.total.mutation.queue.max Available since: 1.7.0
The amount of memory used to store write-ahead-log mutations before flushing them.
type: MEMORY, zk mutable: yes, default value: 5%
tserver.wal.blocksize Available since: 1.5.0
The size of the HDFS blocks used to write to the Write-Ahead log. If zero, it will be 110% of tserver.wal.max.size (that is, try to use just one block)
type: BYTES, zk mutable: yes, default value: 0
tserver.wal.max.age Available since: 2.1.0
The maximum age for each write-ahead log.
type: TIMEDURATION, zk mutable: yes, default value: 24h
tserver.wal.max.referenced Available since: 2.1.0
When a tablet server has more than this many write ahead logs, any tablet referencing older logs over this threshold is minor compacted. Also any tablet referencing this many logs or more will be compacted.
type: COUNT, zk mutable: yes, default value: 3
tserver.wal.max.size Available since: 2.1.0
The maximum size for each write-ahead log. See comment for property tserver.memory.maps.max
type: BYTES, zk mutable: yes, default value: 1G
tserver.wal.maximum.wait.duration Available since: 2.1.0
The maximum amount of time to wait after a failure to create or write a write-ahead log.
type: TIMEDURATION, zk mutable: yes, default value: 5m
tserver.wal.replication Available since: 1.5.0
The replication to use when writing the Write-Ahead log to HDFS. If zero, it will use the HDFS default replication setting.
type: COUNT, zk mutable: yes, default value: 0
tserver.wal.sort.buffer.size Available since: 2.1.0
The amount of memory to use when sorting logs during recovery.
type: MEMORY, zk mutable: yes, default value: 10%
tserver.wal.sort.concurrent.max Available since: 2.1.0
The maximum number of threads to use to sort logs during recovery
type: COUNT, zk mutable: yes, default value: 2
tserver.wal.sort.file.* Available since: 2.1.0
The rfile properties to use when sorting logs during recovery. Most of the properties that begin with ‘table.file’ can be used here. For example, to set the compression of the sorted recovery files to snappy use ‘tserver.wal.sort.file.compress.type=snappy’
tserver.wal.sync Available since: 1.5.0
Use the SYNC_BLOCK create flag to sync WAL writes to disk. Prevents problems recovering from sudden system resets.
type: BOOLEAN, zk mutable: yes, default value: true
tserver.wal.tolerated.creation.failures Available since: 2.1.0
The maximum number of failures tolerated when creating a new write-ahead log. Negative values will allow unlimited creation failures. Exceeding this number of failures consecutively trying to create a new write-ahead log causes the TabletServer to exit.
type: COUNT, zk mutable: yes, default value: 50
tserver.wal.tolerated.wait.increment Available since: 2.1.0
The amount of time to wait between failures to create or write a write-ahead log.
type: TIMEDURATION, zk mutable: yes, default value: 1000ms
tserver.workq.threads Available since: 1.4.2
The number of threads for the distributed work queue. These threads are used for copying failed bulk import RFiles.
type: COUNT, zk mutable: yes, default value: 2

Property Types

Type Description
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
bytes A positive integer optionally followed by a unit of memory (whitespace disallowed).
If no unit is specified, bytes are assumed. Valid units are ‘B’, ‘K’, ‘M’ or ‘G’ for bytes, kilobytes, megabytes, gigabytes.
Examples of valid memories are ‘1024’, ‘20B’, ‘100K’, ‘1500M’, ‘2G’, ‘20%’.
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
memory A positive integer optionally followed by a unit of memory or a percentage (whitespace disallowed).
If a percentage is specified, memory will be a percentage of the max memory allocated to a Java process (set by the JVM option -Xmx).
If no unit is specified, bytes are assumed. Valid units are ‘B’, ‘K’, ‘M’, ‘G’, ‘%’ for bytes, kilobytes, megabytes, gigabytes, and percentage.
Examples of valid memories are ‘1024’, ‘20B’, ‘100K’, ‘1500M’, ‘2G’, ‘20%’.
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
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’
port An positive integer in the range 1024-65535 (not already in use or specified elsewhere in the configuration),
zero to indicate any open ephemeral port, or a range of positive integers specified as M-N
count A non-negative integer in the range of 0-2147483647
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’
path A string that represents a filesystem path, which can be either relative or absolute to some directory. The filesystem depends on the property. Substitutions of the ACCUMULO_HOME environment variable can be done in the system config file using ‘${env:ACCUMULO_HOME}’ or similar.
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.
java class A fully qualified java class name representing a class on the classpath.
An example is ‘java.lang.String’, rather than ‘String’
java class list A list of fully qualified java class names representing classes on the classpath.
An example is ‘java.lang.String’, rather than ‘String’
durability One of ‘none’, ‘log’, ‘flush’ or ‘sync’.
gc_post_action One of ‘none’, ‘flush’, or ‘compact’.
last_location_mode Defines how to update the last location. One of ‘assignment’, or ‘compaction’.
string An arbitrary string of characters whose format is unspecified and interpreted based on the context of the property to which it applies.
boolean Has a value of either ‘true’ or ‘false’ (case-insensitive)
uri A valid URI
file name extension One of the currently supported filename extensions for storing table data files. Currently, only rf is supported.