Elasticsearch has a rich set of APIs that make cluster monitoring a very simple task. We can query and manage pretty much anything in elasticsearch via API.
This is the reason of having so many options out-there to monitor and manage your elasticsearch cluster.
These tools are key when having a multi-node deployment of elasticsearch and you start wondering what did you put on each node or how healthy is your cluster. I recently talked about Cerebro, a simple web admin with a lot of potential.
Today I want to share two other tools that I have tried and tested:
Elastic-Head: Extremely portable solution (it runs as built-in server, docker, Chrome extension or ES plugin). Basic overview and administration of the cluster (sometimes enough!). The interface is not very modern though. The Chrome plugin works like a charm. Apache-license.
ElasticHQ: ElasticHQ rocks. It polls ES almost real-time (every 5 secs) and uses a very modern interface.
The Cluster Diagram will give you full hierarchical visibility of your cluster nodes, shards and indexes.
It also runs a Diagnostic checkup providing hints and color-coded metrics to detect issues.
No installation required. Apache-license.
While these tools can provide a great visibility into your cluster, there is no silver-bullet that will do everything you need.
These free tools will not store historical data for instance but they can certainly be a part of your elasticsearch toolbox!