The index.recovery.max_bytes_per_sec attribute is a configuration parameter in Elasticsearch that controls the maximum data transfer rate during index recovery (e.g., when restarting nodes or recovering replicas). Its primary purpose is to balance recovery speed and cluster performance by limiting bandwidth usage during data recovery, thereby preventing recovery operations from consuming excessive resources and impacting the normal operation and service performance of the cluster.
For example, if recovery bandwidth is not limited, the rapid migration of large volumes of data may consume significant network bandwidth and disk I/O, potentially increasing latency for other critical operations in the cluster, such as customer search requests or real-time indexing of data. By appropriately configuring index.recovery.max_bytes_per_sec (e.g., setting it to 50mb), it is possible to ensure that data recovery proceeds while maintaining the responsiveness and stability of the cluster.
This attribute is typically pre-configured in the cluster settings but can be dynamically adjusted as needed to accommodate different network environments and cluster load conditions. With such configuration, administrators can better manage the recovery process of the cluster, optimizing overall operational efficiency and performance.