Elasticsearch

Links

• http://jprante.github.io/2012/11/28/Elasticsearch-Java-Virtual-Machine-settings-explained.html
• https://www.elastic.co/blog/a-heap-of-trouble

Monitoring elasticsearch

Things to monitor

heap size

• node jvm.mem.heap_used_percent

garbage collection

Something like

node.jvm.uptime_in_millis/node.jvm.gc.collectors.young.collection_count

• How to monitor Elasticsearch performance
• Top 10 Elasticsearch Metrics to Monitor
• Performance metrics to monitor
• Heap Size Usage

Query the web interface

• 'cluster': 'http://localhost:9200/_cluster/stats',
• 'nodes'  : 'http://localhost:9200/_nodes/stats',
• 'indices': 'http://localhost:9200/_stats',
• 'health' : 'http://localhost:9200/_cluster/health'

Installing Elasticsearch

On Debian

deb https://artifacts.elastic.co/packages/oss-6.x/apt stable main

packages is called elasticsearch-oss now?

Terminology

shards

"blocks" of index data distributed over the nodes

Percolation

https://spinscale.de/posts/2021-09-15-understanding-elasticsearch-percolate-query.html

FAQ

Status is yellow

• Yellow cluster status explained

and look for unassigned shards