[[recovery]] === Index recovery Peer recovery syncs data from a primary shard to a new or existing shard copy. Peer recovery automatically occurs when {es}: * Recreates a shard lost during node failure * Relocates a shard to another node due to a cluster rebalance or changes to the <> You can view a list of in-progress and completed recoveries using the <>. [float] ==== Peer recovery settings `indices.recovery.max_bytes_per_sec`:: (<>) Limits total inbound and outbound recovery traffic for each node. Defaults to `40mb`. + This limit applies to each node separately. If multiple nodes in a cluster perform recoveries at the same time, the cluster's total recovery traffic may exceed this limit. + If this limit is too high, ongoing recoveries may consume an excess of bandwidth and other resources, which can destabilize the cluster. + This is a dynamic setting, which means you can set it in each node's `elasticsearch.yml` config file and you can update it dynamically using the <>. If you set it dynamically then the same limit applies on every node in the cluster. If you do not set it dynamically then you can set a different limit on each node, which is useful if some of your nodes have better bandwidth than others. For example, if you are using <> then you may be able to give your hot nodes a higher recovery bandwidth limit than your warm nodes. [float] ==== Expert peer recovery settings You can use the following _expert_ setting to manage resources for peer recoveries. `indices.recovery.max_concurrent_file_chunks`:: (<>, Expert) Number of file chunk requests sent in parallel for each recovery. Defaults to `2`. + You can increase the value of this setting when the recovery of a single shard is not reaching the traffic limit set by `indices.recovery.max_bytes_per_sec`.