WARNING: Version 1.3 of Elasticsearch has passed its EOL date.
This documentation is no longer being maintained and may be removed. If you are running this version, we strongly advise you to upgrade. For the latest information, see the current release documentation.
Translog
editTranslog
editEach shard has a transaction log or write ahead log associated with it. It allows to guarantee that when an index/delete operation occurs, it is applied atomically, while not "committing" the internal Lucene index for each request. A flush ("commit") still happens based on several parameters:
-
index.translog.flush_threshold_ops -
After how many operations to flush. Defaults to
unlimited. -
index.translog.flush_threshold_size -
Once the translog hits this size, a flush will happen. Defaults to
200mb. -
index.translog.flush_threshold_period -
The period with no flush happening to force a flush. Defaults to
30m. -
index.translog.interval -
How often to check if a flush is needed, randomized
between the interval value and 2x the interval value. Defaults to
5s. -
index.gateway.local.sync -
How often the translog is
fsynced to disk. Defaults to5s.
Note: these parameters can be updated at runtime using the Index Settings Update API (for example, these number can be increased when executing bulk updates to support higher TPS)