Elasticsearch: Difference between revisions
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==Configuration== | ==Configuration== | ||
*http://jprante.github.io/2012/11/28/Elasticsearch-Java-Virtual-Machine-settings-explained.html | *http://jprante.github.io/2012/11/28/Elasticsearch-Java-Virtual-Machine-settings-explained.html | ||
===elasticsearch.yml=== | |||
====network.host==== | |||
Takes settings as documented in https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-network.html#network-interface-values | |||
==Heap== | ==Heap== | ||
*https://www.elastic.co/blog/a-heap-of-trouble | *https://www.elastic.co/blog/a-heap-of-trouble | ||
| Line 18: | Line 24: | ||
*Old GC is processed quickly (within 1 second). | *Old GC is processed quickly (within 1 second). | ||
*Old GC is not frequently executed (once per 10 minutes or more). | *Old GC is not frequently executed (once per 10 minutes or more). | ||
==Upgrading Elasticsearch== | |||
*[https://www.elastic.co/docs/deploy-manage/upgrade Upgrade your deployment, cluster, or orchestrator] | |||
=HOWTO= | =HOWTO= | ||
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==Start elasticsearch in safe mode== | ==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" | su -s /bin/bash elasticsearch -c "usr/share/elasticsearch/bin/elasticsearch -E node.ingest=false -E node.master=false -E node.data=false" | ||
==View contents== | |||
curl -H 'Content-Type: application/json' -X GET http://localhost:9200/next_index/_search?pretty | |||
=Monitoring elasticsearch= | =Monitoring elasticsearch= | ||
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/usr/share/elasticsearch/bin/elasticsearch-plugin install ingest-attachment | /usr/share/elasticsearch/bin/elasticsearch-plugin install ingest-attachment | ||
==low disk watermark [85%] exceeded== | |||
Change cluster.routing.allocation.disk.watermark.low or make room | |||
==Get version of active elasticsearch== | ==Get version of active elasticsearch== | ||
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or | or | ||
wget -q -O - http://localhost:9200/_cluster/stats | sed 's/^.*versions\":\[\"\(.*\)\"\].*$/\1\n/g' | wget -q -O - http://localhost:9200/_cluster/stats | sed 's/^.*versions\":\[\"\(.*\)\"\].*$/\1\n/g' | ||
==Error messages== | |||
===org.elasticsearch.ElasticsearchException: Failed to bind service=== | |||
? | |||
==Elasticsearch doesn't get restarted after apt upgrade== | |||
Check | |||
RESTART_ON_UPGRADE | |||
in /etc/default/elasticsearch | |||
Latest revision as of 11:23, 17 November 2025
Links
Documentation
Configuration
elasticsearch.yml
network.host
Takes settings as documented in https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-network.html#network-interface-values
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).
Upgrading Elasticsearch
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"
View contents
curl -H 'Content-Type: application/json' -X GET http://localhost:9200/next_index/_search?pretty
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
low disk watermark [85%] exceeded
Change cluster.routing.allocation.disk.watermark.low or make room
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'
Error messages
org.elasticsearch.ElasticsearchException: Failed to bind service
?
Elasticsearch doesn't get restarted after apt upgrade
Check
RESTART_ON_UPGRADE
in /etc/default/elasticsearch
