EgorBaranovEnjoysTyping commented on code in PR #13714: URL: https://github.com/apache/ignite/pull/13714#discussion_r4358894390
########## docs/_docs/data-rebalancing.adoc: ########## @@ -28,6 +28,83 @@ In pure in-memory clusters, the default behavior is to start rebalancing immedia In clusters with persistence, the baseline topology has to be changed manually (default behavior), or can be changed automatically when link:clustering/baseline-topology#baseline-topology-autoadjustment[automatic baseline adjustment] is enabled. ==== +== Rebalance Strategy [[rebalance-strategy]] + +When a node joins or rejoins the cluster, each partition is restored using one of two strategies: + +- *Full rebalance* — the node downloads the entire partition content from another server node that holds a copy of the partition. +- *Historical rebalance* — the node restores its own data from the local disk and downloads only the delta (WAL entries written while it was absent) from the source node that holds a copy of the partition. + +The strategy is selected per partition based on the following rules: + +. A full rebalance is used if the node has no local data for the partition (update counter is zero). ++ +This applies both to a *new node joining for the first time* (it has no data on disk at all) and to a node that was *evicted from the baseline* and rejoined (its local partition data was invalidated). In both cases the full partition content must be downloaded from another node. Review Comment: "Evicted" is the precise term in Ignite (cf. evictFromTopology). Also note the typo n the suggestion: "than" → "then". -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
