THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
...
As operations modify the table more and more delta files are created and need to be compacted to maintain adequate performance. There are three types of compactions, minor, major and rebalance.
- Minor compaction takes a set of existing delta files and rewrites them to a single delta file per bucket.
- Major compaction takes one or more delta files and the base file for the bucket and rewrites them into a new base file per bucket. Major compaction is more expensive but is more effective.
- More information about rebalance compaction can be found here: Rebalance compaction
...
Configuration key | Values | Location | Notes | ||
Default: org.apache.hadoop.hive.ql.lockmgr.DummyTxnManager Value required for transactions: org.apache.hadoop.hive.ql.lockmgr.DbTxnManager | Client/ | DummyTxnManager replicates pre Hive-0.13 behavior and provides no transactions. | |||
| hive.txn.strict.locking.mode | Default: true | Client/ HiveServer2 | In strict mode non-ACID resources use standard R/W lock semantics, e.g. INSERT will acquire exclusive lock. In non-strict mode, for non-ACID resources, INSERT will only acquire shared lock, which allows two concurrent writes to the same partition but still lets lock manager prevent DROP TABLE etc. when the table is being written to (as of Hive 2.2.0). | ||
hive.txn.timeout deprecated. Use metastore.txn.timeout instead | Default: 300 | Client/ Metastore | Time after which transactions are declared aborted if the client has not sent a heartbeat, in seconds. It's critical that this property has the same value for all components/services.5 | ||
| hive.txn.heartbeat.threadpool.size deprecated - but still in use | Default: 5 | Client/ HiveServer2 | The number of threads to use for heartbeating (as of Hive 1.3.0 and 2.0.0). | ||
| hive.timedout.txn.reaper.start deprecated | Default: 100s | Metastore | Time delay of first reaper (the process which aborts timed-out transactions) run after the metastore starts (as of Hive 1.3.0). Controls AcidHouseKeeperServcie above. | ||
hive.timedout.txn.reaper.interval deprecated | Default: 180s | Metastore | Time interval describing how often the reaper (the process which aborts timed-out transactions) runs (as of Hive 1.3.0). Controls AcidHouseKeeperServcie above. | ||
hive.txn.max.open.batch deprecated. Use metastore.txn.max.open.batch instead | Default: 1000 | Client | Maximum number of transactions that can be fetched in one call to open_txns().1 | ||
| hive.max.open.txns deprecated. Use metastore.max.open.txns instead. | Default: 100000 | HiveServer2/ Metastore | Maximum number of open transactions. If current open transactions reach this limit, future open transaction requests will be rejected, until the number goes below the limit. (As of Hive 1.3.0 and 2.1.0.) | ||
| hive.count.open.txns.interval deprecated. Use metastore.count.open.txns.interval instead. | Default: 1s | HiveServer2/ Metastore | Time in seconds between checks to count open transactions (as of Hive 1.3.0 and 2.1.0). | ||
| hive.txn.retryable.sqlex.regex deprecated. Use metastore.txn.retryable.sqlex.regex instead. | Default: "" (empty string) | HiveServer2/ Metastore | Comma separated list of regular expression patterns for SQL state, error code, and error message of retryable SQLExceptions, that's suitable for the Hive metastore database (as of Hive 1.3.0 and 2.1.0). For an example, see Configuration Properties. | ||
hive.compactor.initiator.on deprecated. Use metastore.compactor.initiator.on instead. | Default: false Value required for transactions: true (for exactly one instance of the Thrift metastore service) | Metastore | Whether to run the initiator thread on this metastore instance. Prior to Hive 1.3.0 it's critical that this is enabled on exactly one standalone metastore service instance (not enforced yet). As of Hive 1.3.0 this property may be enabled on any number of standalone metastore instances. | ||
hive.compactor.cleaner.on deprecated. Use metastore.compactor.cleaner.on instead. | Default: false Value required for transactions: true (for exactly one instance of the Thrift metastore service) | Metastore | Whether to run the cleaner thread on this metastore instance. Before Hive 4.0.0 Cleaner thread can be started/stopped with config hive.compactor.initiator.on. This config helps to enable/disable initiator/cleaner threads independently | ||
| hive.compactor.crud.query.based | Default: false | HiveServer2 | Means compaction on full CRUD tables is done via queries. Compactions on insert-only tables will always run via queries regardless of the value of this configuration. | ||
hive.compactor.worker.threads deprecated. Use metastore.compactor.worker.threads instead. | Default: 0 Value required for transactions: > 0 on at least one instance of the Thrift metastore service | Metastore | How many compactor worker threads to run on this metastore instance.2 | ||
Default: 86400s | Metastore | Time in seconds after which a compaction job will be declared failed and the compaction re-queued. | |||
| hive.compactor.cleaner.run.interval | Default: 5000ms | Metastore | Time in milliseconds between runs of the cleaner thread. (Hive 0.14.0 and later.) | ||
Default: 300s | Metastore | Time in seconds between checks to see if any tables or partitions need to be compacted.3 | |||
Default: 10 | Metastore | Number of delta directories in a table or partition that will trigger a minor compaction. | |||
Default: 0.1 | Metastore | Percentage (fractional) size of the delta files relative to the base that will trigger a major compaction. 1 = 100%, so the default 0.1 = 10%. | |||
Default: 1000 | Metastore | Number of aborted transactions involving a given table or partition that will trigger a major compaction. | |||
| hive.compactor.aborted.txn.time.threshold | Default: 12h | Metastore | Age of table/partition's oldest aborted transaction when compaction will be triggered. Default time unit is: hours. Set to a negative number to disable. | ||
| Default: 500 | Metastore | Maximum number of delta files that the compactor will attempt to handle in a single job (as of Hive 1.3.0).4 | |||
| Default: "" (empty string) | Metastore | Used to specify name of Hadoop queue to which Compaction jobs will be submitted. Set to empty string to let Hadoop choose the queue (as of Hive 1.3.0). | |||
| Compaction History | |||||
hive.compactor.history.retention.succeeded deprecated. Use metastore.compactor.history.retention.succeeded instead | Default: 3 | Metastore | Number of successful compaction entries to retain in history (per partition). | ||
hive.compactor.history.retention.failed deprecated. Use metastore.compactor.history.retention.failed instead. | Default: 3 | Metastore | Number of failed compaction entries to retain in history (per partition). | ||
hive.compactor.history.retention.attempted deprecated. Use metastore.compactor.history.retention.did.not.initiate instead. | Default: 2 | Metastore | Number of attempted compaction entries to retain in history (per partition). | ||
hive.compactor.initiator.failed.compacts.threshold deprecated. Use metastore.compactor.initiator.failed.compacts.threshold instead. | Default: 2 | Metastore | Number of of consecutive failed compactions for a given partition after which the Initiator will stop attempting to schedule compactions automatically. It is still possible to use ALTER TABLE to initiate compaction. Once a manually initiated compaction succeeds auto initiated compactions will resume. Note that this must be less than hive.compactor.history.retention.failed. | ||
hive.compactor.history.reaper.interval deprecated. metastore.acid.housekeeper.interval handles it. | Default: 2m | Metastore | Controls how often the process to purge historical record of compactions runs. | Default: 2m | Metastore |
hive.txn.xlock.iow | Default: true | HiveServer2 | Ensures commands with OVERWRITE (such as INSERT OVERWRITE) acquire Exclusive locks for transactional tables. This ensures that inserts (w/o overwrite) running concurrently are not hidden by the INSERT OVERWRITE. | ||
hive.txn.xlock.write | Default: true | HiveServer2 | Manages concurrency levels for ACID resources. Provides better level of query parallelism by enabling shared writes and write-write conflict resolution at the commit step Controls how often the process to purge historical record of compactions runs. | ||
1metastore.txn.max.open.batch controls how many transactions streaming agents such as Flume or Storm open simultaneously. The streaming agent then writes that number of entries into a single file (per Flume agent or Storm bolt). Thus increasing this value decreases the number of delta files created by streaming agents. But it also increases the number of open transactions that Hive has to track at any given time, which may negatively affect read performance.
...
If a table is to be used in ACID writes (insert, update, delete) then the table property "transactional=true" must must be set on that table, starting with Hive 0.14.0. Note, once a table has been defined as an ACID table via TBLPROPERTIES ("transactional"="true"), it cannot be converted back to a non-ACID table, i.e., changing TBLPROPERTIES ("transactional"="false") is not allowed. Also, hive.txn.manager must be set to org.apache.hadoop.hive.ql.lockmgr.DbTxnManager either in hive-site.xml or in the beginning of the session before any query is run. Without those, inserts will be done in the old style; updates and deletes will be prohibited. Operations Operations on ACID tables without DbTxnManager are not allowed. Additional to "transactional=true", "transactional_properties=insert_only" can be defined to allow only insert transactions.
If a table owner does not wish the system to automatically determine when to compact, then the table property "NO_AUTO_COMPACTION" can be set. This will prevent all automatic compactions. Manual compactions can still be done with Alter Table/Partition Compact statements.
...