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https://github.com/honeymoose/OpenSearch.git
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4a4e3d70d5
This commit changes the default out-of-the-box configuration for the number of shards from five to one. We think this will help address a common problem of oversharding. For users with time-based indices that need a different default, this can be managed with index templates. For users with non-time-based indices that find they need to re-shard with the split API in place they no longer need to resort only to reindexing. Since this has the impact of changing the default number of shards used in REST tests, we want to ensure that we still have coverage for issues that could arise from multiple shards. As such, we randomize (rarely) the default number of shards in REST tests to two. This is managed via a global index template. However, some tests check the templates that are in the cluster state during the test. Since this template is randomly there, we need a way for tests to skip adding the template used to set the number of shards to two. For this we add the default_shards feature skip. To avoid having to write our docs in a complicated way because sometimes they might be behind one shard, and sometimes they might be behind two shards we apply the default_shards feature skip to all docs tests. That is, these tests will always run with the default number of shards (one).
168 lines
4.7 KiB
Plaintext
168 lines
4.7 KiB
Plaintext
[[search-shards]]
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== Search Shards API
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The search shards api returns the indices and shards that a search request would
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be executed against. This can give useful feedback for working out issues or
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planning optimizations with routing and shard preferences. When filtered aliases
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are used, the filter is returned as part of the `indices` section [5.1.0] Added in 5.1.0.
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The `index` may be a single value, or comma-separated.
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[float]
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=== Usage
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Full example:
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[source,js]
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--------------------------------------------------
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GET /twitter/_search_shards
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--------------------------------------------------
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// CONSOLE
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// TEST[s/^/PUT twitter\n{"settings":{"index.number_of_shards":5}}\n/]
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This will yield the following result:
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[source,js]
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--------------------------------------------------
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{
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"nodes": ...,
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"indices" : {
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"twitter": { }
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},
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"shards": [
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 0,
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"state": "STARTED",
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"allocation_id": {"id":"0TvkCyF7TAmM1wHP4a42-A"},
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"relocating_node": null
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}
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],
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 1,
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"state": "STARTED",
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"allocation_id": {"id":"fMju3hd1QHWmWrIgFnI4Ww"},
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"relocating_node": null
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}
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],
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 2,
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"state": "STARTED",
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"allocation_id": {"id":"Nwl0wbMBTHCWjEEbGYGapg"},
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"relocating_node": null
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}
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],
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 3,
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"state": "STARTED",
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"allocation_id": {"id":"bU_KLGJISbW0RejwnwDPKw"},
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"relocating_node": null
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}
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],
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 4,
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"state": "STARTED",
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"allocation_id": {"id":"DMs7_giNSwmdqVukF7UydA"},
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"relocating_node": null
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}
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]
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]
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}
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--------------------------------------------------
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// TESTRESPONSE[s/"nodes": ...,/"nodes": $body.nodes,/]
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// TESTRESPONSE[s/JklnKbD7Tyqi9TP3_Q_tBg/$body.shards.0.0.node/]
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// TESTRESPONSE[s/0TvkCyF7TAmM1wHP4a42-A/$body.shards.0.0.allocation_id.id/]
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// TESTRESPONSE[s/fMju3hd1QHWmWrIgFnI4Ww/$body.shards.1.0.allocation_id.id/]
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// TESTRESPONSE[s/Nwl0wbMBTHCWjEEbGYGapg/$body.shards.2.0.allocation_id.id/]
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// TESTRESPONSE[s/bU_KLGJISbW0RejwnwDPKw/$body.shards.3.0.allocation_id.id/]
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// TESTRESPONSE[s/DMs7_giNSwmdqVukF7UydA/$body.shards.4.0.allocation_id.id/]
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And specifying the same request, this time with a routing value:
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[source,js]
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--------------------------------------------------
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GET /twitter/_search_shards?routing=foo,bar
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--------------------------------------------------
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// CONSOLE
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// TEST[s/^/PUT twitter\n{"settings":{"index.number_of_shards":5}}\n/]
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This will yield the following result:
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[source,js]
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--------------------------------------------------
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{
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"nodes": ...,
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"indices" : {
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"twitter": { }
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},
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"shards": [
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 2,
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"state": "STARTED",
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"allocation_id": {"id":"fMju3hd1QHWmWrIgFnI4Ww"},
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"relocating_node": null
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}
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],
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[
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{
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"index": "twitter",
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"node": "JklnKbD7Tyqi9TP3_Q_tBg",
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"primary": true,
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"shard": 3,
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"state": "STARTED",
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"allocation_id": {"id":"0TvkCyF7TAmM1wHP4a42-A"},
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"relocating_node": null
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}
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]
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]
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}
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--------------------------------------------------
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// TESTRESPONSE[s/"nodes": ...,/"nodes": $body.nodes,/]
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// TESTRESPONSE[s/JklnKbD7Tyqi9TP3_Q_tBg/$body.shards.1.0.node/]
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// TESTRESPONSE[s/0TvkCyF7TAmM1wHP4a42-A/$body.shards.1.0.allocation_id.id/]
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// TESTRESPONSE[s/fMju3hd1QHWmWrIgFnI4Ww/$body.shards.0.0.allocation_id.id/]
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This time the search will only be executed against two of the shards, because
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routing values have been specified.
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[float]
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=== All parameters:
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[horizontal]
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`routing`::
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A comma-separated list of routing values to take into account when
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determining which shards a request would be executed against.
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`preference`::
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Controls a `preference` of which shard replicas to execute the search
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request on. By default, the operation is randomized between the shard
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replicas. See the link:search-request-preference.html[preference]
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documentation for a list of all acceptable values.
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`local`::
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A boolean value whether to read the cluster state locally in order to
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determine where shards are allocated instead of using the Master node's
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cluster state. |