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@@ -1,33 +1,40 @@
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[[recovery]]
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=== Indices Recovery
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-<<cat-recovery,Peer recovery>> is the process used to build a new copy of a
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-shard on a node by copying data from the primary. {es} uses this peer recovery
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-process to rebuild shard copies that were lost if a node has failed, and uses
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-the same process when migrating a shard copy between nodes to rebalance the
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-cluster or to honor any changes to the <<modules-cluster,shard allocation
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-settings>>.
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-
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-The following _expert_ setting can be set to manage the resources consumed by
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-peer recoveries:
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-
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-`indices.recovery.max_bytes_per_sec`::
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- Limits the total inbound and outbound peer recovery traffic on each node.
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- Since this limit applies on each node, but there may be many nodes
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- performing peer recoveries concurrently, the total amount of peer recovery
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- traffic within a cluster may be much higher than this limit. If you set
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- this limit too high then there is a risk that ongoing peer recoveries will
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- consume an excess of bandwidth (or other resources) which could destabilize
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- the cluster. Defaults to `40mb`.
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-
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-`indices.recovery.max_concurrent_file_chunks`::
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- Controls the number of file chunk requests that can be sent in parallel per recovery.
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- As multiple recoveries are already running in parallel (controlled by
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- cluster.routing.allocation.node_concurrent_recoveries), increasing this expert-level
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- setting might only help in situations where peer recovery of a single shard is not
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- reaching the total inbound and outbound peer recovery traffic as configured by
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- indices.recovery.max_bytes_per_sec, but is CPU-bound instead, typically when using
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- transport-level security or compression. Defaults to `2`.
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-
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-This setting can be dynamically updated on a live cluster with the
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-<<cluster-update-settings,cluster-update-settings>> API.
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+Peer recovery syncs data from a primary shard to a new or
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+existing shard copy.
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+
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+Peer recovery automatically occurs when {es}:
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+
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+* Recreates a shard lost during node failure
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+* Relocates a shard to another node due to a cluster rebalance or changes to the
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+<<modules-cluster, shard allocation settings>>
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+
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+You can view a list of in-progress and completed recoveries using the
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+<<cat-recovery, cat recovery API>>.
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+
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+[float]
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+==== Peer recovery settings
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+
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+`indices.recovery.max_bytes_per_sec` (<<cluster-update-settings,Dynamic>>)::
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+Limits total inbound and outbound recovery traffic for each node.
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+Defaults to `40mb`.
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++
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+This limit applies to nodes only. If multiple nodes in a cluster perform
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+recoveries at the same time, the cluster's total recovery traffic may exceed
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+this limit.
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++
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+If this limit is too high, ongoing recoveries may consume an excess
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+of bandwidth and other resources, which can destabilize the cluster.
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+
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+[float]
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+==== Expert peer recovery settings
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+You can use the following _expert_ setting to manage resources for peer
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+recoveries.
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+
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+`indices.recovery.max_concurrent_file_chunks` (<<cluster-update-settings,Dynamic>>, Expert)::
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+Number of file chunk requests sent in parallel for each recovery. Defaults to
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+`2`.
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++
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+You can increase the value of this setting when the recovery of a single shard
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+is not reaching the traffic limit set by `indices.recovery.max_bytes_per_sec`.
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