w3ll1ngt commented on code in PR #13130: URL: https://github.com/apache/ignite/pull/13130#discussion_r3626898295
########## docs/_docs/perf-and-troubleshooting/general-perf-tips.adoc: ########## @@ -47,3 +47,393 @@ queries with JOINs at massive scale and expect significant performance benefits. * Adjust link:data-rebalancing[data rebalancing settings] to ensure that rebalancing completes faster when your cluster topology changes. +== How to assess cluster health + +Cluster health is a complex thing. Apache Ignite is capable of demonstrating great performance across different scenarios with varying loads. Therefore, in general terms, a healthy cluster is one whose behavior aligns with your expectations. However, there are some universal aspects that apply to all deployments and warrant attention. + +It is important to understand that a healthy cluster may undergo planned topology changes or temporary load spikes. + +The key properties are: + +* The cluster is in the intended link:monitoring-metrics/cluster-states[state] and serves only the operations allowed by that state. +* Baseline topology, when it is used or managed manually, matches the expected data-bearing server nodes. +* Data remains consistent: link:tools/control-script#verifying-partition-checksums[`idle_verify`] reports no partition conflicts when the cluster is idle. +* Expected nodes are present, and no node segmentation or repeated membership churn is reported. +* link:configuring-caches/partition-loss-policy[Lost partitions] are absent. +* Long-running transactions, Partition Map Exchange (PME), rebalancing, checkpointing, and executor queues converge instead of accumulating. + +There is no single command or metric that proves cluster health for every deployment. + +Use several signals together. +A simple client connection or SQL liveness check can prove only that a particular client or query path is reachable; it does not check user partitions, backup consistency, baseline membership, or all server nodes. +Similarly, `control.(sh|bat) --cache idle_verify` is an important consistency check, but it is still not a complete health check. Review Comment: last line removed. finally -- 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]
