Monitoring Elasticsearch

Monitoring distributed systems is difficult because as the number of nodes, the number of users, and the amount of data increase, problems will begin to crop up.

Furthermore, it may not be immediately obvious if there is an error. Often, the cluster will keep running and try to recover from the error automatically. As shown in Figures 1.2, 1.3, and 1.4 earlier, a node failed, but Elasticsearch brought itself back to a green state without any action on our part. Unless monitored, failures such as these can go unnoticed. This can have a detrimental impact on system performance and reliability. Fewer nodes means less processing power to respond to queries, and, as in the previous example, if another node fails, our cluster ...