Marvel enables you to easily monitor Elasticsearch through Kibana. You can view your cluster’s health and performance in real time as well as analyze past cluster, index, and node metrics.
While you can access a large number of statistics through the APIs described in this chapter, they only show you what’s going on at a single point in time. Knowing memory usage at this instant is helpful, but knowing memory usage over time is much more useful. Marvel queries and aggregates the metrics so you can visualize your cluster’s behavior over time, which makes it easy to spot trends.
As your cluster grows, the output from the stats APIs can get truly hairy. Once you have a dozen nodes, let alone a hundred, reading through stacks of JSON becomes very tedious. Marvel lets you explore the data interactively and makes it easy to zero in on what’s going on with particular nodes or indices.
Marvel uses the same stats APIs that are available to you—it does not expose any statistics that you can’t access through the APIs. However, Marvel greatly simplifies the collection and visualization of those statistics.
Marvel is free to use (even in production!), so you should definitely try it out! For installation instructions, see Getting Started with Marvel.