ACCUMULO-4630 Refactored documentation for website * Converted asciidoc to markdown * Created sidebar navigation * Added back images
Project: http://git-wip-us.apache.org/repos/asf/accumulo-website/repo Commit: http://git-wip-us.apache.org/repos/asf/accumulo-website/commit/7cc70b2e Tree: http://git-wip-us.apache.org/repos/asf/accumulo-website/tree/7cc70b2e Diff: http://git-wip-us.apache.org/repos/asf/accumulo-website/diff/7cc70b2e Branch: refs/heads/master Commit: 7cc70b2efedfc1f6acf779d7b3fbf26c7062ae11 Parents: 32ac61d Author: Mike Walch <mwa...@apache.org> Authored: Tue May 16 11:07:50 2017 -0400 Committer: Mike Walch <mwa...@apache.org> Committed: Mon May 22 13:18:03 2017 -0400 ---------------------------------------------------------------------- _config.yml | 30 + .../administration/configuration-management.md | 91 ++ .../administration/configuration-properties.md | 265 ++++ _docs-unreleased/administration/fate.md | 73 ++ _docs-unreleased/administration/kerberos.md | 605 +++++++++ _docs-unreleased/administration/multivolume.md | 73 ++ _docs-unreleased/administration/overview.md | 1151 ++++++++++++++++++ _docs-unreleased/administration/replication.md | 385 ++++++ _docs-unreleased/administration/ssl.md | 124 ++ _docs-unreleased/development/analytics.md | 226 ++++ .../development/development_tools.md | 102 ++ .../development/high_speed_ingest.md | 113 ++ _docs-unreleased/development/iterator_design.md | 386 ++++++ .../development/iterator_testing.md | 97 ++ _docs-unreleased/development/sampling.md | 75 ++ _docs-unreleased/development/security.md | 169 +++ _docs-unreleased/development/summaries.md | 222 ++++ _docs-unreleased/getting-started/clients.md | 381 ++++++ _docs-unreleased/getting-started/design.md | 165 +++ _docs-unreleased/getting-started/shell.md | 145 +++ .../getting-started/table_configuration.md | 664 ++++++++++ .../getting-started/table_design.md | 303 +++++ _docs-unreleased/index.md | 16 + _docs-unreleased/troubleshooting/overview.md | 820 +++++++++++++ _layouts/default.hml | 2 +- _layouts/docs-unreleased.html | 47 + _layouts/post.html | 9 +- css/accumulo.scss | 18 +- docs/master/administration.md | 1145 ----------------- docs/master/analytics.md | 229 ---- docs/master/clients.md | 403 ------ docs/master/design.md | 180 --- docs/master/development_clients.md | 107 -- docs/master/high_speed_ingest.md | 124 -- docs/master/implementation.md | 86 -- docs/master/introduction.md | 25 - docs/master/iterator_design.md | 401 ------ docs/master/iterator_test_harness.md | 110 -- docs/master/kerberos.md | 663 ---------- docs/master/multivolume.md | 82 -- docs/master/replication.md | 399 ------ docs/master/sampling.md | 86 -- docs/master/security.md | 182 --- docs/master/shell.md | 159 --- docs/master/ssl.md | 134 -- docs/master/summaries.md | 232 ---- docs/master/table_configuration.md | 670 ---------- docs/master/table_design.md | 336 ----- docs/master/troubleshooting.md | 845 ------------- images/docs/data_distribution.png | Bin 0 -> 86937 bytes images/docs/failure_handling.png | Bin 0 -> 48905 bytes images/docs/key_value.png | Bin 0 -> 9899 bytes 52 files changed, 6750 insertions(+), 6605 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/accumulo-website/blob/7cc70b2e/_config.yml ---------------------------------------------------------------------- diff --git a/_config.yml b/_config.yml index 51c5122..ef56ee4 100644 --- a/_config.yml +++ b/_config.yml @@ -20,6 +20,15 @@ num_home_posts: 5 # Build settings markdown: kramdown +# Collection names cannot contain periods +collections: + docs-unreleased: + output: true + permalink: "/docs/unreleased/:path" +# docs-2-0: +# output: true +# permalink: "/docs/2.0/:path" + defaults: - scope: @@ -42,5 +51,26 @@ defaults: layout: "release" category: "release" permalink: "/:categories/:title/" + - + scope: + path: "" + type: "docs-unreleased" + values: + layout: "docs-unreleased" + title_prefix: "Accumulo Documentation - " + version: "unreleased" + docs_baseurl: "/docs/unreleased" + skiph1fortitle: "true" +# - +# scope: +# path: "" +# type: "docs-2-0" +# values: +# layout: "docs-2.0" +# title_prefix: "Accumulo Documentation - " +# version: "2.0" +# docs_baseurl: "/docs/2.0" +# skiph1fortitle: "true" + whitelist: [jekyll-redirect-from] gems: [jekyll-redirect-from] http://git-wip-us.apache.org/repos/asf/accumulo-website/blob/7cc70b2e/_docs-unreleased/administration/configuration-management.md ---------------------------------------------------------------------- diff --git a/_docs-unreleased/administration/configuration-management.md b/_docs-unreleased/administration/configuration-management.md new file mode 100644 index 0000000..a1c83ee --- /dev/null +++ b/_docs-unreleased/administration/configuration-management.md @@ -0,0 +1,91 @@ +--- +title: Configuration Management +category: administration +order: 2 +--- + +## 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): + +### 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 command: + + config -t TABLE -s PROPERTY=VALUE + +### 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*. + +### 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 synced 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. + +### Default Values + +All properties have a default value in the source code. This value has the lowest precedence and is overridden 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. + +### ZooKeeper Property Considerations + +Any properties that are stored in ZooKeeper should consider the limitations of ZooKeeper itself with respect to the +number of nodes and the size of the node data. Custom table properties and options for Iterators configured on tables +are two areas in which there aren't any fail safes built into the API that can prevent the user from making this mistake. + +While these properties have the ability to add some much needed dynamic configuration tools, use cases which might fall +into these warnings should be reconsidered. + +## 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: 2.x.x +- 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 +``` http://git-wip-us.apache.org/repos/asf/accumulo-website/blob/7cc70b2e/_docs-unreleased/administration/configuration-properties.md ---------------------------------------------------------------------- diff --git a/_docs-unreleased/administration/configuration-properties.md b/_docs-unreleased/administration/configuration-properties.md new file mode 100644 index 0000000..b8cd1ff --- /dev/null +++ b/_docs-unreleased/administration/configuration-properties.md @@ -0,0 +1,265 @@ +--- +title: Configuration Properties +category: administration +order: 3 +--- + +<!-- WARNING: Do not edit this file. It is a generated file that is copied from Accumulo build (from core/target/generated-docs) --> + +| Property | Description | +|--------------|-------------| +| <a name="gc_prefix"></a> **gc.*** | Properties in this category affect the behavior of the accumulo garbage collector. | +| <a name="gc_cycle_delay"></a> gc.cycle.delay | Time between garbage collection cycles. In each cycle, old files no longer in use are removed from the filesystem.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5m` | +| <a name="gc_cycle_start"></a> gc.cycle.start | Time to wait before attempting to garbage collect any old files.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `30s` | +| <a name="gc_file_archive"></a> gc.file.archive | Archive any files/directories instead of moving to the HDFS trash or deleting.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="gc_port_client"></a> gc.port.client | The listening port for the garbage collector's monitor service<br>**type:** PORT, **zk mutable:** yes but requires restart of the gc, **default value:** `9998` | +| <a name="gc_threads_delete"></a> gc.threads.delete | The number of threads used to delete files<br>**type:** COUNT, **zk mutable:** yes, **default value:** `16` | +| <a name="gc_trace_percent"></a> gc.trace.percent | Percent of gc cycles to trace<br>**type:** FRACTION, **zk mutable:** yes, **default value:** `0.01` | +| <a name="gc_trash_ignore"></a> gc.trash.ignore | Do not use the Trash, even if it is configured.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="general_prefix"></a> **general.*** | Properties in this category affect the behavior of accumulo overall, but do not have to be consistent throughout a cloud. | +| <a name="general_classpaths"></a> general.classpaths | **Deprecated.** ~~This property is deprecated. The class path should instead be configured by the launch environment (for example, accumulo-env.sh). 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. Supports full regex on filename alone.~~<br>~~**type:** STRING~~, ~~**zk mutable:** no~~, ~~**default value:** empty~~ | +| <a name="general_custom_prefix"></a> **general.custom.*** | 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. | +| <a name="general_delegation_token_lifetime"></a> general.delegation.token.lifetime | The length of time that delegation tokens and secret keys are valid<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `7d` | +| <a name="general_delegation_token_update_interval"></a> general.delegation.token.update.interval | The length of time between generation of new secret keys<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `1d` | +| <a name="general_dynamic_classpaths"></a> general.dynamic.classpaths | A list of all of the places where changes in jars or classes will force a reload of the classloader.<br>**type:** STRING, **zk mutable:** no, **default value:** `$ACCUMULO_HOME/lib/ext/[^.].*.jar` | +| <a name="general_kerberos_keytab"></a> general.kerberos.keytab | Path to the kerberos keytab to use. Leave blank if not using kerberoized hdfs<br>**type:** PATH, **zk mutable:** no, **default value:** empty | +| <a name="general_kerberos_principal"></a> 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<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="general_kerberos_renewal_period"></a> general.kerberos.renewal.period | 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).<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `30s` | +| <a name="general_legacy_metrics"></a> general.legacy.metrics | Use the old metric infrastructure configured by accumulo-metrics.xml, instead of Hadoop Metrics2<br>**type:** BOOLEAN, **zk mutable:** no, **default value:** `false` | +| <a name="general_max_scanner_retry_period"></a> general.max.scanner.retry.period | The maximum amount of time that a Scanner should wait before retrying a failed RPC<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `5s` | +| <a name="general_rpc_timeout"></a> general.rpc.timeout | Time to wait on I/O for simple, short RPC calls<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `120s` | +| <a name="general_security_credential_provider_paths"></a> general.security.credential.provider.paths | Comma-separated list of paths to CredentialProviders<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="general_server_message_size_max"></a> general.server.message.size.max | The maximum size of a message that can be sent to a server.<br>**type:** BYTES, **zk mutable:** no, **default value:** `1G` | +| <a name="general_server_simpletimer_threadpool_size"></a> general.server.simpletimer.threadpool.size | The number of threads to use for server-internal scheduled tasks<br>**type:** COUNT, **zk mutable:** no, **default value:** `1` | +| <a name="general_vfs_cache_dir"></a> 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}<br>**type:** ABSOLUTEPATH, **zk mutable:** no, **default value:** `${java.io.tmpdir}/accumulo-vfs-cache-${user.name}` | +| <a name="general_vfs_classpaths"></a> general.vfs.classpaths | Configuration for a system level vfs classloader. Accumulo jar can be configured here and loaded out of HDFS.<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="general_vfs_context_classpath_prefix"></a> **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. | +| <a name="instance_prefix"></a> **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. | +| <a name="instance_dfs_dir"></a> instance.dfs.dir | **Deprecated.** ~~HDFS directory in which accumulo instance will run. Do not change after accumulo is initialized.~~<br>~~**type:** ABSOLUTEPATH~~, ~~**zk mutable:** no~~, ~~**default value:** `/accumulo`~~ | +| <a name="instance_dfs_uri"></a> 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).~~<br>~~**type:** URI~~, ~~**zk mutable:** no~~, ~~**default value:** empty~~ | +| <a name="instance_rpc_sasl_allowed_host_impersonation"></a> instance.rpc.sasl.allowed.host.impersonation | One-line configuration property controlling the network locations (hostnames) that are allowed to impersonate other users<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="instance_rpc_sasl_allowed_user_impersonation"></a> instance.rpc.sasl.allowed.user.impersonation | One-line configuration property controlling what users are allowed to impersonate other users<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="instance_rpc_sasl_enabled"></a> instance.rpc.sasl.enabled | Configures Thrift RPCs to require SASL with GSSAPI which supports Kerberos authentication. Mutually exclusive with SSL RPC configuration.<br>**type:** BOOLEAN, **zk mutable:** no, **default value:** `false` | +| <a name="instance_rpc_sasl_impersonation_prefix"></a> **instance.rpc.sasl.impersonation.*** | **Deprecated.** ~~Prefix that allows configuration of users that are allowed to impersonate other users~~ | +| <a name="instance_rpc_ssl_clientAuth"></a> instance.rpc.ssl.clientAuth | Require clients to present certs signed by a trusted root<br>**type:** BOOLEAN, **zk mutable:** no, **default value:** `false` | +| <a name="instance_rpc_ssl_enabled"></a> instance.rpc.ssl.enabled | Use SSL for socket connections from clients and among accumulo services. Mutually exclusive with SASL RPC configuration.<br>**type:** BOOLEAN, **zk mutable:** no, **default value:** `false` | +| <a name="instance_secret"></a> instance.secret | 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-site.xml 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<br>**type:** STRING, **zk mutable:** no, **default value:** `DEFAULT` | +| <a name="instance_security_authenticator"></a> instance.security.authenticator | The authenticator class that accumulo will use to determine if a user has privilege to perform an action<br>**type:** CLASSNAME, **zk mutable:** no, **default value:** `org.apache.accumulo.server.security.handler.ZKAuthenticator` | +| <a name="instance_security_authorizor"></a> instance.security.authorizor | The authorizor class that accumulo will use to determine what labels a user has privilege to see<br>**type:** CLASSNAME, **zk mutable:** no, **default value:** `org.apache.accumulo.server.security.handler.ZKAuthorizor` | +| <a name="instance_security_permissionHandler"></a> instance.security.permissionHandler | The permission handler class that accumulo will use to determine if a user has privilege to perform an action<br>**type:** CLASSNAME, **zk mutable:** no, **default value:** `org.apache.accumulo.server.security.handler.ZKPermHandler` | +| <a name="instance_volumes"></a> 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.<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="instance_volumes_replacements"></a> 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 separated 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 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.<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="instance_zookeeper_host"></a> instance.zookeeper.host | Comma separated list of zookeeper servers<br>**type:** HOSTLIST, **zk mutable:** no, **default value:** `localhost:2181` | +| <a name="instance_zookeeper_timeout"></a> instance.zookeeper.timeout | Zookeeper session timeout; max value when represented as milliseconds should be no larger than 2147483647<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `30s` | +| <a name="master_prefix"></a> **master.*** | Properties in this category affect the behavior of the master server | +| <a name="master_bulk_rename_threadpool_size"></a> master.bulk.rename.threadpool.size | The number of threads to use when moving user files to bulk ingest directories under accumulo control<br>**type:** COUNT, **zk mutable:** yes, **default value:** `20` | +| <a name="master_bulk_retries"></a> master.bulk.retries | The number of attempts to bulk-load a file before giving up.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `3` | +| <a name="master_bulk_threadpool_size"></a> master.bulk.threadpool.size | The number of threads to use when coordinating a bulk-import.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `5` | +| <a name="master_bulk_timeout"></a> master.bulk.timeout | The time to wait for a tablet server to process a bulk import request<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5m` | +| <a name="master_fate_threadpool_size"></a> master.fate.threadpool.size | The number of threads used to run FAult-Tolerant Executions. These are primarily table operations like merge.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `4` | +| <a name="master_lease_recovery_interval"></a> master.lease.recovery.interval | The amount of time to wait after requesting a WAL file to be recovered<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5s` | +| <a name="master_metadata_suspendable"></a> master.metadata.suspendable | Allow tablets for the accumulo.metadata table to be suspended via table.suspend.duration.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="master_port_client"></a> master.port.client | The port used for handling client connections on the master<br>**type:** PORT, **zk mutable:** yes but requires restart of the master, **default value:** `9999` | +| <a name="master_recovery_delay"></a> 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.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `10s` | +| <a name="master_recovery_max_age"></a> master.recovery.max.age | Recovery files older than this age will be removed.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `60m` | +| <a name="master_recovery_time_max"></a> master.recovery.time.max | The maximum time to attempt recovery before giving up<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `30m` | +| <a name="master_replication_coordinator_minthreads"></a> master.replication.coordinator.minthreads | Minimum number of threads dedicated to answering coordinator requests<br>**type:** COUNT, **zk mutable:** yes, **default value:** `4` | +| <a name="master_replication_coordinator_port"></a> master.replication.coordinator.port | Port for the replication coordinator service<br>**type:** PORT, **zk mutable:** yes, **default value:** `10001` | +| <a name="master_replication_coordinator_threadcheck_time"></a> master.replication.coordinator.threadcheck.time | The time between adjustments of the coordinator thread pool<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5s` | +| <a name="master_replication_status_scan_interval"></a> master.replication.status.scan.interval | Amount of time to sleep before scanning the status section of the replication table for new data<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `30s` | +| <a name="master_server_threadcheck_time"></a> master.server.threadcheck.time | The time between adjustments of the server thread pool.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1s` | +| <a name="master_server_threads_minimum"></a> master.server.threads.minimum | The minimum number of threads to use to handle incoming requests.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `20` | +| <a name="master_status_threadpool_size"></a> master.status.threadpool.size | The number of threads to use when fetching the tablet server status for balancing.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1` | +| <a name="master_tablet_balancer"></a> master.tablet.balancer | The balancer class that accumulo will use to make tablet assignment and migration decisions.<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.server.master.balancer.TableLoadBalancer` | +| <a name="master_walog_closer_implementation"></a> master.walog.closer.implementation | A class that implements a mechansim to steal write access to a file<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.server.master.recovery.HadoopLogCloser` | +| <a name="monitor_prefix"></a> **monitor.*** | Properties in this category affect the behavior of the monitor web server. | +| <a name="monitor_banner_background"></a> monitor.banner.background | The background color of the banner text displayed on the monitor page.<br>**type:** STRING, **zk mutable:** yes, **default value:** `#304065` | +| <a name="monitor_banner_color"></a> monitor.banner.color | The color of the banner text displayed on the monitor page.<br>**type:** STRING, **zk mutable:** yes, **default value:** `#c4c4c4` | +| <a name="monitor_banner_text"></a> monitor.banner.text | The banner text displayed on the monitor page.<br>**type:** STRING, **zk mutable:** yes, **default value:** empty | +| <a name="monitor_lock_check_interval"></a> monitor.lock.check.interval | The amount of time to sleep between checking for the Montior ZooKeeper lock<br>**type:** TIMEDURATION, **zk mutable:** no, **default value:** `5s` | +| <a name="monitor_log_date_format"></a> monitor.log.date.format | The SimpleDateFormat string used to configure the date shown on the 'Recent Logs' monitor page<br>**type:** STRING, **zk mutable:** no, **default value:** `yyyy/MM/dd HH:mm:ss,SSS` | +| <a name="monitor_port_client"></a> monitor.port.client | The listening port for the monitor's http service<br>**type:** PORT, **zk mutable:** no, **default value:** `9995` | +| <a name="monitor_port_log4j"></a> monitor.port.log4j | The listening port for the monitor's log4j logging collection.<br>**type:** PORT, **zk mutable:** no, **default value:** `4560` | +| <a name="monitor_ssl_exclude_ciphers"></a> monitor.ssl.exclude.ciphers | A comma-separated list of disallowed SSL Ciphers, see mmonitor.ssl.include.ciphers to allow ciphers<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="monitor_ssl_include_ciphers"></a> monitor.ssl.include.ciphers | A comma-separated list of allows SSL Ciphers, see monitor.ssl.exclude.ciphers to disallow ciphers<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="monitor_ssl_include_protocols"></a> monitor.ssl.include.protocols | A comma-separate list of allowed SSL protocols<br>**type:** STRING, **zk mutable:** no, **default value:** `TLSv1,TLSv1.1,TLSv1.2` | +| <a name="monitor_ssl_keyStore"></a> monitor.ssl.keyStore | The keystore for enabling monitor SSL.<br>**type:** PATH, **zk mutable:** no, **default value:** empty | +| <a name="monitor_ssl_keyStorePassword"></a> monitor.ssl.keyStorePassword | The keystore password for enabling monitor SSL.<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="monitor_ssl_keyStoreType"></a> monitor.ssl.keyStoreType | Type of SSL keystore<br>**type:** STRING, **zk mutable:** no, **default value:** `jks` | +| <a name="monitor_ssl_trustStore"></a> monitor.ssl.trustStore | The truststore for enabling monitor SSL.<br>**type:** PATH, **zk mutable:** no, **default value:** empty | +| <a name="monitor_ssl_trustStorePassword"></a> monitor.ssl.trustStorePassword | The truststore password for enabling monitor SSL.<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="monitor_ssl_trustStoreType"></a> monitor.ssl.trustStoreType | Type of SSL truststore<br>**type:** STRING, **zk mutable:** no, **default value:** `jks` | +| <a name="replication_prefix"></a> **replication.*** | Properties in this category affect the replication of data to other Accumulo instances. | +| <a name="replication_driver_delay"></a> replication.driver.delay | Amount of time to wait before the replication work loop begins in the master.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `0s` | +| <a name="replication_max_unit_size"></a> replication.max.unit.size | Maximum size of data to send in a replication message<br>**type:** BYTES, **zk mutable:** yes, **default value:** `64M` | +| <a name="replication_max_work_queue"></a> replication.max.work.queue | Upper bound of the number of files queued for replication<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1000` | +| <a name="replication_name"></a> replication.name | Name of this cluster with respect to replication. Used to identify this instance from other peers<br>**type:** STRING, **zk mutable:** yes, **default value:** empty | +| <a name="replication_peer_prefix"></a> **replication.peer.*** | Properties in this category control what systems data can be replicated to | +| <a name="replication_peer_keytab_prefix"></a> **replication.peer.keytab.*** | The keytab to use when authenticating with the given peer | +| <a name="replication_peer_password_prefix"></a> **replication.peer.password.*** | The password to provide when authenticating with the given peer | +| <a name="replication_peer_user_prefix"></a> **replication.peer.user.*** | The username to provide when authenticating with the given peer | +| <a name="replication_receipt_service_port"></a> replication.receipt.service.port | Listen port used by thrift service in tserver listening for replication<br>**type:** PORT, **zk mutable:** yes, **default value:** `10002` | +| <a name="replication_receiver_min_threads"></a> replication.receiver.min.threads | Minimum number of threads for replication<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1` | +| <a name="replication_receiver_threadcheck_time"></a> replication.receiver.threadcheck.time | The time between adjustments of the replication thread pool.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `30s` | +| <a name="replication_rpc_timeout"></a> replication.rpc.timeout | Amount of time for a single replication RPC call to last before failing the attempt. See replication.work.attempts.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `2m` | +| <a name="replication_trace_percent"></a> replication.trace.percent | The sampling percentage to use for replication traces<br>**type:** FRACTION, **zk mutable:** yes, **default value:** `0.1` | +| <a name="replication_work_assigner"></a> replication.work.assigner | Replication WorkAssigner implementation to use<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.master.replication.UnorderedWorkAssigner` | +| <a name="replication_work_assignment_sleep"></a> replication.work.assignment.sleep | Amount of time to sleep between replication work assignment<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `30s` | +| <a name="replication_work_attempts"></a> replication.work.attempts | Number of attempts to try to replicate some data before giving up and letting it naturally be retried later<br>**type:** COUNT, **zk mutable:** yes, **default value:** `10` | +| <a name="replication_work_processor_delay"></a> replication.work.processor.delay | Amount of time to wait before first checking for replication work, not useful outside of tests<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `0s` | +| <a name="replication_work_processor_period"></a> replication.work.processor.period | Amount of time to wait before re-checking for replication work, not useful outside of tests<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `0s` | +| <a name="replication_worker_threads"></a> replication.worker.threads | Size of the threadpool that each tabletserver devotes to replicating data<br>**type:** COUNT, **zk mutable:** yes, **default value:** `4` | +| <a name="rpc_prefix"></a> **rpc.*** | Properties in this category related to the configuration of SSL keys for RPC. See also instance.ssl.enabled | +| <a name="rpc_javax_net_ssl_keyStore"></a> rpc.javax.net.ssl.keyStore | Path of the keystore file for the server's private SSL key<br>**type:** PATH, **zk mutable:** no, **default value:** empty | +| <a name="rpc_javax_net_ssl_keyStorePassword"></a> rpc.javax.net.ssl.keyStorePassword | Password used to encrypt the SSL private keystore. Leave blank to use the Accumulo instance secret<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="rpc_javax_net_ssl_keyStoreType"></a> rpc.javax.net.ssl.keyStoreType | Type of SSL keystore<br>**type:** STRING, **zk mutable:** no, **default value:** `jks` | +| <a name="rpc_javax_net_ssl_trustStore"></a> rpc.javax.net.ssl.trustStore | Path of the truststore file for the root cert<br>**type:** PATH, **zk mutable:** no, **default value:** empty | +| <a name="rpc_javax_net_ssl_trustStorePassword"></a> rpc.javax.net.ssl.trustStorePassword | Password used to encrypt the SSL truststore. Leave blank to use no password<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="rpc_javax_net_ssl_trustStoreType"></a> rpc.javax.net.ssl.trustStoreType | Type of SSL truststore<br>**type:** STRING, **zk mutable:** no, **default value:** `jks` | +| <a name="rpc_sasl_qop"></a> rpc.sasl.qop | The quality of protection to be used with SASL. Valid values are 'auth', 'auth-int', and 'auth-conf'<br>**type:** STRING, **zk mutable:** no, **default value:** `auth` | +| <a name="rpc_ssl_cipher_suites"></a> rpc.ssl.cipher.suites | Comma separated list of cipher suites that can be used by accepted connections<br>**type:** STRING, **zk mutable:** no, **default value:** empty | +| <a name="rpc_ssl_client_protocol"></a> rpc.ssl.client.protocol | 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)<br>**type:** STRING, **zk mutable:** no, **default value:** `TLSv1` | +| <a name="rpc_ssl_server_enabled_protocols"></a> rpc.ssl.server.enabled.protocols | Comma separated list of protocols that can be used to accept connections<br>**type:** STRING, **zk mutable:** no, **default value:** `TLSv1,TLSv1.1,TLSv1.2` | +| <a name="rpc_useJsse"></a> rpc.useJsse | Use JSSE system properties to configure SSL rather than the rpc.javax.net.ssl.* Accumulo properties<br>**type:** BOOLEAN, **zk mutable:** no, **default value:** `false` | +| <a name="table_prefix"></a> **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. | +| <a name="table_balancer"></a> table.balancer | This property can be set to allow the LoadBalanceByTable load balancer to change the called Load Balancer for this table<br>**type:** STRING, **zk mutable:** yes, **default value:** `org.apache.accumulo.server.master.balancer.DefaultLoadBalancer` | +| <a name="table_bloom_enabled"></a> table.bloom.enabled | Use bloom filters on this table.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="table_bloom_error_rate"></a> table.bloom.error.rate | Bloom filter error rate.<br>**type:** FRACTION, **zk mutable:** yes, **default value:** `0.5%` | +| <a name="table_bloom_hash_type"></a> table.bloom.hash.type | The bloom filter hash type<br>**type:** STRING, **zk mutable:** yes, **default value:** `murmur` | +| <a name="table_bloom_key_functor"></a> 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. <br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.core.file.keyfunctor.RowFunctor` | +| <a name="table_bloom_load_threshold"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1` | +| <a name="table_bloom_size"></a> table.bloom.size | Bloom filter size, as number of keys.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1048576` | +| <a name="table_cache_block_enable"></a> table.cache.block.enable | Determines whether file block cache is enabled.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="table_cache_index_enable"></a> table.cache.index.enable | Determines whether index cache is enabled.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `true` | +| <a name="table_classpath_context"></a> table.classpath.context | Per table classpath context<br>**type:** STRING, **zk mutable:** yes, **default value:** empty | +| <a name="table_compaction_major_everything_idle"></a> 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.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1h` | +| <a name="table_compaction_major_ratio"></a> 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.<br>**type:** FRACTION, **zk mutable:** yes, **default value:** `3` | +| <a name="table_compaction_minor_idle"></a> 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.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5m` | +| <a name="table_compaction_minor_logs_threshold"></a> 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<br>**type:** COUNT, **zk mutable:** yes, **default value:** `3` | +| <a name="table_compaction_minor_merge_file_size_max"></a> table.compaction.minor.merge.file.size.max | The max file size used for a merging minor compaction. The default value of 0 disables a max file size.<br>**type:** BYTES, **zk mutable:** yes, **default value:** `0` | +| <a name="table_constraint_prefix"></a> **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.<br>For example:<br>table.constraint.1 = org.apache.accumulo.core.constraints.MyCustomConstraint<br>and:<br>table.constraint.2 = my.package.constraints.MySecondConstraint | +| <a name="table_custom_prefix"></a> **table.custom.*** | Prefix to be used for user defined arbitrary properties. | +| <a name="table_durability"></a> table.durability | 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.<br>**type:** DURABILITY, **zk mutable:** yes, **default value:** `sync` | +| <a name="table_failures_ignore"></a> 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.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="table_file_blocksize"></a> table.file.blocksize | Overrides the hadoop dfs.block.size setting so that files have better query performance. The maximum value for this is 2147483647<br>**type:** BYTES, **zk mutable:** yes, **default value:** `0B` | +| <a name="table_file_compress_blocksize"></a> 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.)<br>**type:** BYTES, **zk mutable:** yes, **default value:** `100K` | +| <a name="table_file_compress_blocksize_index"></a> 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.)<br>**type:** BYTES, **zk mutable:** yes, **default value:** `128K` | +| <a name="table_file_compress_type"></a> table.file.compress.type | One of gz,snappy,lzo,none<br>**type:** STRING, **zk mutable:** yes, **default value:** `gz` | +| <a name="table_file_max"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `15` | +| <a name="table_file_replication"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `0` | +| <a name="table_file_summary_maxSize"></a> table.file.summary.maxSize | The maximum size summary that will be stored. The number of files that had summary data exceeding this threshold is reported by Summary.getFileStatistics().getLarge(). When adjusting this consider the expected number files with summaries on each tablet server and the summary cache size.<br>**type:** BYTES, **zk mutable:** yes, **default value:** `256K` | +| <a name="table_file_type"></a> table.file.type | Change the type of file a table writes<br>**type:** STRING, **zk mutable:** yes, **default value:** `rf` | +| <a name="table_formatter"></a> table.formatter | The Formatter class to apply on results in the shell<br>**type:** STRING, **zk mutable:** yes, **default value:** `org.apache.accumulo.core.util.format.DefaultFormatter` | +| <a name="table_group_prefix"></a> **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.<br>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.<br>Additional group options may be specified for a named group by setting table.group.<name>.opt.<key>=<value>. | +| <a name="table_groups_enabled"></a> table.groups.enabled | A comma separated list of locality group names to enable for this table.<br>**type:** STRING, **zk mutable:** yes, **default value:** empty | +| <a name="table_interepreter"></a> table.interepreter | The ScanInterpreter class to apply on scan arguments in the shell<br>**type:** STRING, **zk mutable:** yes, **default value:** `org.apache.accumulo.core.util.interpret.DefaultScanInterpreter` | +| <a name="table_iterator_prefix"></a> **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:<br> table.iterator.scan.vers = 10,org.apache.accumulo.core.iterators.VersioningIterator<br> 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.<br>For example, table.iterator.minc.vers.opt.maxVersions = 3 | +| <a name="table_iterator_majc_prefix"></a> **table.iterator.majc.*** | Convenience prefix to find options for the majc iterator scope | +| <a name="table_iterator_minc_prefix"></a> **table.iterator.minc.*** | Convenience prefix to find options for the minc iterator scope | +| <a name="table_iterator_scan_prefix"></a> **table.iterator.scan.*** | Convenience prefix to find options for the scan iterator scope | +| <a name="table_majc_compaction_strategy"></a> table.majc.compaction.strategy | A customizable major compaction strategy.<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.tserver.compaction.DefaultCompactionStrategy` | +| <a name="table_majc_compaction_strategy_opts_prefix"></a> **table.majc.compaction.strategy.opts.*** | Properties in this category are used to configure the compaction strategy. | +| <a name="table_replication"></a> table.replication | Is replication enabled for the given table<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="table_replication_target_prefix"></a> **table.replication.target.*** | Enumerate a mapping of other systems which this table should replicate their data to. The key suffix is the identifying cluster name and the value is an identifier for a location on the target system, e.g. the ID of the table on the target to replicate to | +| <a name="table_sampler"></a> table.sampler | 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 files without sample data.<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** empty | +| <a name="table_sampler_opt_prefix"></a> **table.sampler.opt.*** | 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. | +| <a name="table_scan_max_memory"></a> 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.<br>**type:** BYTES, **zk mutable:** yes, **default value:** `512K` | +| <a name="table_security_scan_visibility_default"></a> table.security.scan.visibility.default | The security label that will be assumed at scan time if an entry does not have a visibility set.<br>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.<br>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.<br>**type:** STRING, **zk mutable:** yes, **default value:** empty | +| <a name="table_split_endrow_size_max"></a> table.split.endrow.size.max | Maximum size of end row<br>**type:** BYTES, **zk mutable:** yes, **default value:** `10K` | +| <a name="table_split_threshold"></a> table.split.threshold | When combined size of files exceeds this amount a tablet is split.<br>**type:** BYTES, **zk mutable:** yes, **default value:** `1G` | +| <a name="table_summarizer_prefix"></a> **table.summarizer.*** | 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>. | +| <a name="table_suspend_duration"></a> table.suspend.duration | For tablets belonging to this table: When a tablet server dies, allow the tablet server this duration to revive before reassigning its tabletsto other tablet servers.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `0s` | +| <a name="table_walog_enabled"></a> table.walog.enabled | **Deprecated.** ~~This setting is deprecated. Use table.durability=none instead.~~<br>~~**type:** BOOLEAN~~, ~~**zk mutable:** yes~~, ~~**default value:** `true`~~ | +| <a name="trace_prefix"></a> **trace.*** | Properties in this category affect the behavior of distributed tracing. | +| <a name="trace_password"></a> trace.password | The password for the user used to store distributed traces<br>**type:** STRING, **zk mutable:** no, **default value:** `secret` | +| <a name="trace_port_client"></a> trace.port.client | The listening port for the trace server<br>**type:** PORT, **zk mutable:** no, **default value:** `12234` | +| <a name="trace_span_receiver_prefix"></a> **trace.span.receiver.*** | Prefix for span receiver configuration properties | +| <a name="trace_span_receivers"></a> trace.span.receivers | A list of span receiver classes to send trace spans<br>**type:** CLASSNAMELIST, **zk mutable:** no, **default value:** `org.apache.accumulo.tracer.ZooTraceClient` | +| <a name="trace_table"></a> trace.table | The name of the table to store distributed traces<br>**type:** STRING, **zk mutable:** no, **default value:** `trace` | +| <a name="trace_token_property_prefix"></a> **trace.token.property.*** | The prefix used to create a token for storing distributed traces. For each property required by trace.token.type, place this prefix in front of it. | +| <a name="trace_token_type"></a> trace.token.type | An AuthenticationToken type supported by the authorizer<br>**type:** CLASSNAME, **zk mutable:** no, **default value:** `org.apache.accumulo.core.client.security.tokens.PasswordToken` | +| <a name="trace_user"></a> trace.user | The name of the user to store distributed traces<br>**type:** STRING, **zk mutable:** no, **default value:** `root` | +| <a name="trace_zookeeper_path"></a> trace.zookeeper.path | The zookeeper node where tracers are registered<br>**type:** STRING, **zk mutable:** no, **default value:** `/tracers` | +| <a name="tserver_prefix"></a> **tserver.*** | Properties in this category affect the behavior of the tablet servers | +| <a name="tserver_archive_walogs"></a> tserver.archive.walogs | Keep copies of the WALOGs for debugging purposes<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="tserver_assignment_concurrent_max"></a> tserver.assignment.concurrent.max | The number of threads available to load tablets. Recoveries are still performed serially.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `2` | +| <a name="tserver_assignment_duration_warning"></a> tserver.assignment.duration.warning | 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<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `10m` | +| <a name="tserver_bloom_load_concurrent_max"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `4` | +| <a name="tserver_bulk_assign_threads"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1` | +| <a name="tserver_bulk_process_threads"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1` | +| <a name="tserver_bulk_retry_max"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `5` | +| <a name="tserver_bulk_timeout"></a> tserver.bulk.timeout | The time to wait for a tablet server to process a bulk import request.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5m` | +| <a name="tserver_cache_data_size"></a> tserver.cache.data.size | Specifies the size of the cache for file data blocks.<br>**type:** MEMORY, **zk mutable:** yes, **default value:** `10%` | +| <a name="tserver_cache_index_size"></a> tserver.cache.index.size | Specifies the size of the cache for file indices.<br>**type:** MEMORY, **zk mutable:** yes, **default value:** `25%` | +| <a name="tserver_cache_policy"></a> tserver.cache.policy | Specifies the eviction policy of the file data caches (LRU or TinyLFU).<br>**type:** STRING, **zk mutable:** yes, **default value:** `LRU` | +| <a name="tserver_cache_summary_size"></a> tserver.cache.summary.size | Specifies the size of the cache for summary data on each tablet server.<br>**type:** MEMORY, **zk mutable:** yes, **default value:** `10%` | +| <a name="tserver_client_timeout"></a> tserver.client.timeout | Time to wait for clients to continue scans before closing a session.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `3s` | +| <a name="tserver_compaction_major_concurrent_max"></a> tserver.compaction.major.concurrent.max | The maximum number of concurrent major compactions for a tablet server<br>**type:** COUNT, **zk mutable:** yes, **default value:** `3` | +| <a name="tserver_compaction_major_delay"></a> tserver.compaction.major.delay | Time a tablet server will sleep between checking which tablets need compaction.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `30s` | +| <a name="tserver_compaction_major_thread_files_open_max"></a> tserver.compaction.major.thread.files.open.max | Max number of files a major compaction thread can open at once. <br>**type:** COUNT, **zk mutable:** yes, **default value:** `10` | +| <a name="tserver_compaction_major_throughput"></a> tserver.compaction.major.throughput | Maximum number of bytes to read or write per second over all major compactions on a TabletServer, or 0B for unlimited.<br>**type:** BYTES, **zk mutable:** yes, **default value:** `0B` | +| <a name="tserver_compaction_major_trace_percent"></a> tserver.compaction.major.trace.percent | The percent of major compactions to trace<br>**type:** FRACTION, **zk mutable:** yes, **default value:** `0.1` | +| <a name="tserver_compaction_minor_concurrent_max"></a> tserver.compaction.minor.concurrent.max | The maximum number of concurrent minor compactions for a tablet server<br>**type:** COUNT, **zk mutable:** yes, **default value:** `4` | +| <a name="tserver_compaction_minor_trace_percent"></a> tserver.compaction.minor.trace.percent | The percent of minor compactions to trace<br>**type:** FRACTION, **zk mutable:** yes, **default value:** `0.1` | +| <a name="tserver_compaction_warn_time"></a> tserver.compaction.warn.time | When a compaction has not made progress for this time period, a warning will be logged<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `10m` | +| <a name="tserver_default_blocksize"></a> tserver.default.blocksize | Specifies a default blocksize for the tserver caches<br>**type:** BYTES, **zk mutable:** yes, **default value:** `1M` | +| <a name="tserver_dir_memdump"></a> 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.<br>**type:** PATH, **zk mutable:** yes, **default value:** `/tmp` | +| <a name="tserver_files_open_idle"></a> 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.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1m` | +| <a name="tserver_hold_time_max"></a> 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.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5m` | +| <a name="tserver_memory_manager"></a> tserver.memory.manager | An implementation of MemoryManger that accumulo will use.<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.server.tabletserver.LargestFirstMemoryManager` | +| <a name="tserver_memory_maps_max"></a> 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.<br>**type:** MEMORY, **zk mutable:** yes, **default value:** `33%` | +| <a name="tserver_memory_maps_native_enabled"></a> 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.<br>**type:** BOOLEAN, **zk mutable:** yes but requires restart of the tserver, **default value:** `true` | +| <a name="tserver_metadata_readahead_concurrent_max"></a> tserver.metadata.readahead.concurrent.max | The maximum number of concurrent metadata read ahead that will execute.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `8` | +| <a name="tserver_migrations_concurrent_max"></a> tserver.migrations.concurrent.max | The maximum number of concurrent tablet migrations for a tablet server<br>**type:** COUNT, **zk mutable:** yes, **default value:** `1` | +| <a name="tserver_monitor_fs"></a> 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.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `true` | +| <a name="tserver_mutation_queue_max"></a> tserver.mutation.queue.max | **Deprecated.** ~~This setting is deprecated. See tserver.total.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.~~<br>~~**type:** BYTES~~, ~~**zk mutable:** yes~~, ~~**default value:** `1M`~~ | +| <a name="tserver_port_client"></a> tserver.port.client | The port used for handling client connections on the tablet servers<br>**type:** PORT, **zk mutable:** yes but requires restart of the tserver, **default value:** `9997` | +| <a name="tserver_port_search"></a> tserver.port.search | if the ports above are in use, search higher ports until one is available<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `false` | +| <a name="tserver_readahead_concurrent_max"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `16` | +| <a name="tserver_recovery_concurrent_max"></a> tserver.recovery.concurrent.max | The maximum number of threads to use to sort logs during recovery<br>**type:** COUNT, **zk mutable:** yes, **default value:** `2` | +| <a name="tserver_replication_batchwriter_replayer_memory"></a> tserver.replication.batchwriter.replayer.memory | Memory to provide to batchwriter to replay mutations for replication<br>**type:** BYTES, **zk mutable:** yes, **default value:** `50M` | +| <a name="tserver_replication_default_replayer"></a> tserver.replication.default.replayer | Default AccumuloReplicationReplayer implementation<br>**type:** CLASSNAME, **zk mutable:** yes, **default value:** `org.apache.accumulo.tserver.replication.BatchWriterReplicationReplayer` | +| <a name="tserver_replication_replayer_prefix"></a> **tserver.replication.replayer.*** | Allows configuration of implementation used to apply replicated data | +| <a name="tserver_scan_files_open_max"></a> tserver.scan.files.open.max | Maximum total files that all tablets in a tablet server can open for scans. <br>**type:** COUNT, **zk mutable:** yes but requires restart of the tserver, **default value:** `100` | +| <a name="tserver_server_message_size_max"></a> tserver.server.message.size.max | The maximum size of a message that can be sent to a tablet server.<br>**type:** BYTES, **zk mutable:** yes, **default value:** `1G` | +| <a name="tserver_server_threadcheck_time"></a> tserver.server.threadcheck.time | The time between adjustments of the server thread pool.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1s` | +| <a name="tserver_server_threads_minimum"></a> tserver.server.threads.minimum | The minimum number of threads to use to handle incoming requests.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `20` | +| <a name="tserver_session_idle_max"></a> tserver.session.idle.max | 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<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1m` | +| <a name="tserver_session_update_idle_max"></a> tserver.session.update.idle.max | 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<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1m` | +| <a name="tserver_slow_flush_time"></a> tserver.slow.flush.time | 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.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `100ms` | +| <a name="tserver_sort_buffer_size"></a> tserver.sort.buffer.size | The amount of memory to use when sorting logs during recovery.<br>**type:** MEMORY, **zk mutable:** yes, **default value:** `10%` | +| <a name="tserver_summary_partition_threads"></a> tserver.summary.partition.threads | Summary data must be retrieved from files. For a large number of files, the files are broken into partitions of 100K files. This setting determines how many of these groups of 100K files will be processed concurrently.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `10` | +| <a name="tserver_summary_remote_threads"></a> tserver.summary.remote.threads | For a partitioned group of 100K files, 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `128` | +| <a name="tserver_summary_retrieval_threads"></a> tserver.summary.retrieval.threads | The number of threads on each tablet server available to retrieve summary data, that is not currently in cache, from RFiles.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `10` | +| <a name="tserver_tablet_split_midpoint_files_max"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `300` | +| <a name="tserver_total_mutation_queue_max"></a> tserver.total.mutation.queue.max | The amount of memory used to store write-ahead-log mutations before flushing them.<br>**type:** MEMORY, **zk mutable:** yes, **default value:** `5%` | +| <a name="tserver_wal_blocksize"></a> 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)<br>**type:** BYTES, **zk mutable:** yes, **default value:** `0` | +| <a name="tserver_wal_replication"></a> 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.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `0` | +| <a name="tserver_wal_sync"></a> tserver.wal.sync | Use the SYNC_BLOCK create flag to sync WAL writes to disk. Prevents problems recovering from sudden system resets.<br>**type:** BOOLEAN, **zk mutable:** yes, **default value:** `true` | +| <a name="tserver_wal_sync_method"></a> tserver.wal.sync.method | **Deprecated.** ~~This property is deprecated. Use table.durability instead.~~<br>~~**type:** STRING~~, ~~**zk mutable:** yes~~, ~~**default value:** `hsync`~~ | +| <a name="tserver_walog_max_age"></a> tserver.walog.max.age | The maximum age for each write-ahead log.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `24h` | +| <a name="tserver_walog_max_size"></a> tserver.walog.max.size | The maximum size for each write-ahead log. See comment for property tserver.memory.maps.max<br>**type:** BYTES, **zk mutable:** yes, **default value:** `1g` | +| <a name="tserver_walog_maximum_wait_duration"></a> tserver.walog.maximum.wait.duration | The maximum amount of time to wait after a failure to create a WAL file.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `5m` | +| <a name="tserver_walog_tolerated_creation_failures"></a> tserver.walog.tolerated.creation.failures | The maximum number of failures tolerated when creating a new WAL file within the period specified by tserver.walog.failures.period. Exceeding this number of failures in the period causes the TabletServer to exit.<br>**type:** COUNT, **zk mutable:** yes, **default value:** `50` | +| <a name="tserver_walog_tolerated_wait_increment"></a> tserver.walog.tolerated.wait.increment | The amount of time to wait between failures to create a WALog.<br>**type:** TIMEDURATION, **zk mutable:** yes, **default value:** `1000ms` | +| <a name="tserver_workq_threads"></a> tserver.workq.threads | The number of threads for the distributed work queue. These threads are used for copying failed bulk files.<br>**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.<br>If no unit of time is specified, seconds are assumed. Valid units are 'ms', 's', 'm', 'h' for milliseconds, seconds, minutes, and hours.<br>Examples of valid durations are '600', '30s', '45m', '30000ms', '3d', and '1h'.<br>Examples of invalid durations are '1w', '1h30m', '1s 200ms', 'ms', '', and 'a'.<br>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).<br>If no unit is specified, bytes are assumed. Valid units are 'B', 'K', 'M' or 'G' for bytes, kilobytes, megabytes, gigabytes.<br>Examples of valid memories are '1024', '20B', '100K', '1500M', '2G', '20%'.<br>Examples of invalid memories are '1M500K', '1M 2K', '1MB', '1.5G', '1,024K', '', and 'a'.<br>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).<br>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).<br>If no unit is specified, bytes are assumed. Valid units are 'B', 'K', 'M', 'G', '%' for bytes, kilobytes, megabytes, gigabytes, and percentage.<br>Examples of valid memories are '1024', '20B', '100K', '1500M', '2G', '20%'.<br>Examples of invalid memories are '1M500K', '1M 2K', '1MB', '1.5G', '1,024K', '', and 'a'.<br>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.<br>Examples of valid host lists are 'localhost:2000,www.example.com,10.10.1.1:500' and 'localhost'.<br>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),<br>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.<br>Examples of valid fractions/percentages are '10', '1000%', '0.05', '5%', '0.2%', '0.0005'.<br>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. The following environment variables will be substituted: [ACCUMULO_HOME, ACCUMULO_CONF_DIR] | +| 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.<br>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.<br>An example is 'java.lang.String', rather than 'String' | +| durability | One of 'none', 'log', 'flush' or 'sync'. | +| 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 | http://git-wip-us.apache.org/repos/asf/accumulo-website/blob/7cc70b2e/_docs-unreleased/administration/fate.md ---------------------------------------------------------------------- diff --git a/_docs-unreleased/administration/fate.md b/_docs-unreleased/administration/fate.md new file mode 100644 index 0000000..ce0647e --- /dev/null +++ b/_docs-unreleased/administration/fate.md @@ -0,0 +1,73 @@ +--- +title: FATE +category: administration +order: 6 +--- + +Accumulo must implement a number of distributed, multi-step operations to support +the client API. Creating a new table is a simple example of an atomic client call +which requires multiple steps in the implementation: get a unique table ID, configure +default table permissions, populate information in ZooKeeper to record the table's +existence, create directories in HDFS for the table's data, etc. Implementing these +steps in a way that is tolerant to node failure and other concurrent operations is +very difficult to achieve. Accumulo includes a Fault-Tolerant Executor (FATE) which +is widely used server-side to implement the client API safely and correctly. + +Fault-Tolerant Executor (FATE) is the implementation detail which ensures that tables in creation when the +Master dies will be successfully created when another Master process is started. +This alleviates the need for any external tools to correct some bad state -- Accumulo can +undo the failure and self-heal without any external intervention. + +## Overview + +FATE consists of two primary components: a repeatable, persisted operation (REPO), a storage +layer for REPOs and an execution system to run REPOs. Accumulo uses ZooKeeper as the storage +layer for FATE and the Accumulo Master acts as the execution system to run REPOs. + +The important characteristic of REPOs are that they implemented in a way that is idempotent: +every operation must be able to undo or replay a partial execution of itself. Requiring the +implementation of the operation to support this functional greatly simplifies the execution +of these operations. This property is also what guarantees safety in light of failure conditions. + +## Administration + +Sometimes, it is useful to inspect the current FATE operations, both pending and executing. +For example, a command that is not completing could be blocked on the execution of another +operation. Accumulo provides an Accumulo shell command to interact with fate. + +The `fate` shell command accepts a number of arguments for different functionality: +`list`/`print`, `fail`, `delete`, `dump`. + +### List/Print + +Without any additional arguments, this command will print all operations that still exist in +the FATE store (ZooKeeper). This will include active, pending, and completed operations (completed +operations are lazily removed from the store). Each operation includes a unique "transaction ID", the +state of the operation (e.g. `NEW`, `IN_PROGRESS`, `FAILED`), any locks the +transaction actively holds and any locks it is waiting to acquire. + +This option can also accept transaction IDs which will restrict the list of transactions shown. + +### Fail + +This command can be used to manually fail a FATE transaction and requires a transaction ID +as an argument. Failing an operation is not a normal procedure and should only be performed +by an administrator who understands the implications of why they are failing the operation. + +### Delete + +This command requires a transaction ID and will delete any locks that the transaction +holds. Like the fail command, this command should only be used in extreme circumstances +by an administrator that understands the implications of the command they are about to +invoke. It is not normal to invoke this command. + +### Dump + +This command accepts zero more transaction IDs. If given no transaction IDs, +it will dump all active transactions. A FATE operations is compromised as a +sequence of REPOs. In order to start a FATE transaction, a REPO is pushed onto +a per transaction REPO stack. The top of the stack always contains the next +REPO the FATE transaction should execute. When a REPO is successful it may +return another REPO which is pushed on the stack. The `dump` command will +print all of the REPOs on each transactions stack. The REPOs are serialized to +JSON in order to make them human readable.
