2013-08-28 19:24:34 -04:00
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[[index-modules-translog]]
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== Translog
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Each shard has a transaction log or write ahead log associated with it.
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It allows to guarantee that when an index/delete operation occurs, it is
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applied atomically, while not "committing" the internal Lucene index for
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each request. A flush ("commit") still happens based on several
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parameters:
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[cols="<,<",options="header",]
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|=======================================================================
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|Setting |Description
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|index.translog.flush_threshold_ops |After how many operations to flush.
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2014-04-22 08:29:26 -04:00
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Defaults to `unlimited`.
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2013-08-28 19:24:34 -04:00
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|index.translog.flush_threshold_size |Once the translog hits this size,
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a flush will happen. Defaults to `200mb`.
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|index.translog.flush_threshold_period |The period with no flush
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happening to force a flush. Defaults to `30m`.
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2014-01-07 13:58:16 -05:00
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|index.translog.interval |How often to check if a flush is needed, randomized
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between the interval value and 2x the interval value. Defaults to `5s`.
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2013-08-28 19:24:34 -04:00
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|=======================================================================
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Note: these parameters can be updated at runtime using the Index
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Settings Update API (for example, these number can be increased when
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executing bulk updates to support higher TPS)
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