Derric Gilling troubleshoots an Elasticsearch cluster:
Because of this sharding, a read or write request to an Elasticsearch cluster requires coordinating between multiple nodes as there is no “global view” of your data on a single server. While this makes Elasticsearch highly scalable, it also makes it much more complex to setup and tune than other popular databases like MongoDB or PostgresSQL, which can run on a single server.
When reliability issues come up, firefighting can be stressful if your Elasticsearch setup is buggy or unstable. Your incident could be impacting customers which could negatively impact revenue and your business reputation. Fast remediation steps are important, yet spending a large amount of time researching solutions online during an incident or outage is not a luxury most engineers have. This guide is intended to be a cheat sheet for common issues that engineers running that can cause issues with Elasticsearch and what to look for.
Read on for several helpful tips.