Today we have two variants of translogs for indexing. We only recommend the buffered
one which also has a 20% advantage in indexing speed. This commit removes the option and defaults
to the buffered case. It also hard-wires the translog buffer to 8kb instead of 64kb. We used to
adjust that buffer based on if the shard is active or not, this code has also been removed and
instead we just keep an 8kb buffer arround.
This commit removes `index.translog.flush_threshold_ops` and `index.translog.disable_flush`
in favor of `index.translog.flush_threshold_size`. The number of operations is meaningless by itself and
can easily be turned into a size value with knowledge of the data. Disabling the flush is only useful in
tests and we can set the size value to a really high value. If users really need to do this they can
also apply a very high value like `1PB`.
- moves calculation of the delay to a single place (ReplicaShardAllocator)
- reduces coupling between GatewayAllocator and RoutingService
- in master failover situations, elapsed delay time is forgotten
Closes#14808
This adds the `cluster.routing.allocation.total_shards_per_node`
setting, which limits the total number of shards across all indices on
each node. It defaults to -1 and can be dynamically configured.
Resolves#14456
This commit moves the size and ops based flush into a synchronous API into
IndexShard and removes the time-based flush alltogether since it' basically
covered by the inactive async flush API we have today. The functionality doesn't
need to be covered by scheduled task and async APIs while we can actually make all
the decisions in a sync manner which is way easier to control and to test.
Closes#13707
Allocation filtering by IP only works today using the node host address. But in some cases, you might want to filter using the publish address which could be different.
Instead of logging the entire `_source` in the indexing slowlog we log by
default just the first 1000 characters - this is controlled by the
`index.indexing.slowlog.source` settings and can be set to `true` to log the
whole `_source`, `false` to log none of it, and a number to log at most that
many characters.
Closes#4485
Change the default delayed allocation timeout from 0 (no delayed allocation) to 1m. The value came from a test of having a node with 50 shards being indexed into (so beefy translog requiring flush on shutdown), then shutting it down and starting it back up and waiting for it to join the cluster. This took, on a slow machine, about 30s.
The value is conservatively low and does not try to address a virtual machine / OS restart for now, in order to not have the affect of node going away and users being concerned that shards are not being allocated to the rest of the cluster as a result of that. The setting can always be changed in order to increase the delayed allocation if needed.
closes#12166
Now that doc values are the default for fielddata, specialized in-memory
formats are becoming an esoteric option. This commit removes such formats:
- `fst` on string fields,
- `compressed` on geo points.
I also removed documentation and tests that the fielddata cache is shared if
you change the format, since this is only true for in-memory fielddata formats
(given that for doc values, the caching is done directly in Lucene).
Today we provide the ability to plug in MergePolicy and
we provide the once lucene ships with. We do not recommend to change
the default and even only a small number of expert users would ever touch
this. This commit removes the ancient log byte size and log doc count
merge policy providers, simplifies the MergePolicy wiring and makes the
tiered MP the one and only default. All notions of a merge policy has been
removed from the docs and should be deprecated in the previous version.
Closes#11588
Using files that must be specified on each node is an anti-pattern
from the API based goal of ES. This change removes the ability
to specify the default mapping with a file on each node.
closes#10620
In order to safely complete recoveries / relocations we have to keep all operation done since the recovery start at available for replay. At the moment we do so by preventing the engine from flushing and thus making sure that the operations are kept in the translog. A side effect of this is that the translog keeps on growing until the recovery is done. This is not a problem as we do need these operations but if the another recovery starts concurrently it may have an unneededly long translog to replay. Also, if we shutdown the engine for some reason at this point (like when a node is restarted) we have to recover a long translog when we come back.
To void this, the translog is changed to be based on multiple files instead of a single one. This allows recoveries to keep hold to the files they need while allowing the engine to flush and do a lucene commit (which will create a new translog files bellow the hood).
Change highlights:
- Refactor Translog file management to allow for multiple files.
- Translog maintains a list of referenced files, both by outstanding recoveries and files containing operations not yet committed to Lucene.
- A new Translog.View concept is introduced, allowing recoveries to get a reference to all currently uncommitted translog files plus all future translog files created until the view is closed. They can use this view to iterate over operations.
- Recovery phase3 is removed. That phase was replaying operations while preventing new writes to the engine. This is unneeded as standard indexing also send all operations from the start of the recovery to the recovering shard. Replay all ops in the view acquired in recovery start is enough to guarantee no operation is lost.
- IndexShard now creates the translog together with the engine. The translog is closed by the engine on close. ShadowIndexShards do not open the translog.
- Moved the ownership of translog fsyncing to the translog it self, changing the responsible setting to `index.translog.sync_interval` (was `index.gateway.local.sync`)
Closes#10624
* Removed the docs for `index.compound_format` and `index.compound_on_flush` - these are expert settings which should probably be removed (see https://github.com/elastic/elasticsearch/issues/10778)
* Removed the docs for `index.index_concurrency` - another expert setting
* Labelled the segments verbose output as experimental
* Marked the `compression`, `precision_threshold` and `rehash` options as experimental in the cardinality and percentile aggs
* Improved the experimental text on `significant_terms`, `execution_hint` in the terms agg, and `terminate_after` param on count and search
* Removed the experimental flag on the `geobounds` agg
* Marked the settings in the `merge` and `store` modules as experimental, rather than the modules themselves
Closes#10782
This commit brings the benefits of the `count` search type to search requests
that have a `size` of 0:
- a single round-trip to shards (no fetch phase)
- ability to use the query cache
Since `count` now provides no benefits over `query_then_fetch`, it has been
deprecated.
Close#7630
We now have a very useful annotation to mark features or parameters as
experimental. Let's use it! This commit replaces some custom text warnings with
this annotation and adds this annotation to some existing features/parameters:
- inner_hits (unreleased yet)
- terminate_after (released in 1.4)
- per-bucket doc count errors in the terms agg (released in 1.4)
I also tagged with this annotation settings which should either be not needed
(like the ability to evict entries from the filter cache based on time) or that
are too deep into the way that Elasticsearch works like the Directory
implementation or merge settings.
Close#9563
Robert Muir
Jim Ferenczi
Simon Willnauer
Clinton Gormley
William
Yannick Welsch
Lee Hinman
Jason O'Donnell
David Pilato
Michael McCandless
Nik Everett
Shay Banon
Adrien Grand
Martijn van Groningen
Pascal Borreli
Ryan Ernst
Boaz Leskes
Joshua Rich
Masaru Hasegawa
Itamar Syn-Hershko