Improve performance of shards limits decider #53577
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On clusters with a large number of shards, the shards limits allocation decider can exhibit poor performance leading to timeouts applying cluster state updates. This occurs because for every shard, we do a loop to count the number of shards on the node, and the number of shards for the index of the shard. This is roughly quadratic in the number of shards. This loop is not necessary, since we already have a O(1) method to count the number of non-relocating shards on a node, and with this commit we add some infrastructure to RoutingNode to make counting the number of shards per index O(1).
jasontedor
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:Distributed Coordination/Allocation
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Pinging @elastic/es-distributed (:Distributed/Allocation) |
henningandersen
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Mar 18, 2020
server/src/main/java/org/elasticsearch/cluster/routing/RoutingNode.java
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server/src/test/java/org/elasticsearch/cluster/routing/RoutingNodeTests.java
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…Node.java Co-Authored-By: Henning Andersen <[email protected]>
…NodeTests.java Co-Authored-By: Henning Andersen <[email protected]>
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@elasticmachine update branch |
jasontedor
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On clusters with a large number of shards, the shards limits allocation decider can exhibit poor performance leading to timeouts applying cluster state updates. This occurs because for every shard, we do a loop to count the number of shards on the node, and the number of shards for the index of the shard. This is roughly quadratic in the number of shards. This loop is not necessary, since we already have a O(1) method to count the number of non-relocating shards on a node, and with this commit we add some infrastructure to RoutingNode to make counting the number of shards per index O(1).
jasontedor
added a commit
that referenced
this pull request
Mar 19, 2020
On clusters with a large number of shards, the shards limits allocation decider can exhibit poor performance leading to timeouts applying cluster state updates. This occurs because for every shard, we do a loop to count the number of shards on the node, and the number of shards for the index of the shard. This is roughly quadratic in the number of shards. This loop is not necessary, since we already have a O(1) method to count the number of non-relocating shards on a node, and with this commit we add some infrastructure to RoutingNode to make counting the number of shards per index O(1).
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On clusters with a large number of shards, the shards limits allocation decider can exhibit poor performance leading to timeouts applying cluster state updates. This occurs because for every shard, we do a loop to count the number of shards on the node, and the number of shards for the index of the shard. This is roughly quadratic in the number of shards. This loop is not necessary, since we already have a O(1) method to count the number of non-relocating shards on a node, and with this commit we add some infrastructure to RoutingNode to make counting the number of shards per index O(1).
Closes #53559