w3ll1ngt commented on code in PR #13130: URL: https://github.com/apache/ignite/pull/13130#discussion_r3603370192
########## docs/_docs/perf-and-troubleshooting/general-perf-tips.adoc: ########## @@ -47,3 +47,345 @@ 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 serves operations allowed by its intended state. +- Data remains consistent (`idle_verify` passes, meaning partitions are intact and there are no conflicts). +- Expected nodes are present. +- No pending transactions and no split brain. +- No lost partitions. +- Transient activity such as rebalancing or queue growth converges instead of accumulating. + +But the thing is, there is no universal single health metric. + +Use several signals together. +For example, `SELECT 1` can confirm that a client or SQL query path is reachable, but it does not check user partitions, backup consistency, baseline membership, or all server nodes. Review Comment: completely refurbished this line -- 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]
