Elasticsearch
From DWIKI
Links
Documentation
Configuration
Heap
Garbage collection
Ideally:
- Young GC is processed quickly (within 50 ms).
- Young GC is not frequently executed (about 10 seconds).
- Old GC is processed quickly (within 1 second).
- Old GC is not frequently executed (once per 10 minutes or more).
HOWTO
Adjust log rotation
Is done in /etc/elasticsearch/log4j.properties
Number of logfiles to keep
appender.rolling.strategy.max
Start elasticsearch in safe mode
su -s /bin/bash elasticsearch -c "usr/share/elasticsearch/bin/elasticsearch -E node.ingest=false -E node.master=false -E node.data=false"
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
now throttling indexing for shard: segment writing can't keep up
FAQ
Status is yellow
and look for unassigned shards
Update ingest-attachment
/usr/share/elasticsearch/bin/elasticsearch-plugin remove ingest-attachment /usr/share/elasticsearch/bin/elasticsearch-plugin install ingest-attachment
Get version of active elasticsearch
wget -q -O - http://localhost:9200/_cluster/stats
or
wget -q -O - http://localhost:9200/_cluster/stats | sed 's/^.*versions\":\[\"\(.*\)\"\].*$/\1\n/g'
