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Graylog JVM Heap Optimization

·113 words
Journal Performance Graylog Jvm Docker

What Changed
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Pinned Graylog’s JVM heap to 1GB by adding explicit GRAYLOG_SERVER_JAVA_OPTS to docker-compose.yml:

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GRAYLOG_SERVER_JAVA_OPTS: "-Xms1g -Xmx1g -XX:NewRatio=1 -server -XX:+UseG1GC"

Why
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Noticed high memory usage on the Graylog VM. JVM ergonomics was auto-allocating ~2GB for Graylog, leaving insufficient RAM for OS filesystem cache. OpenSearch query performance suffers without cache headroom.

Details
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  • Service: Graylog (Log-Server VM)
  • File changed: graylog/docker-compose.yml
  • Deployed via: Portainer Git stack (auto-pulls from repo)

Memory allocation now:

ComponentRAM
OpenSearch1 GB
Graylog1 GB
OS + cache~2 GB

Result
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~1GB freed for filesystem cache. OpenSearch can now cache index files in RAM, improving query response times.

Detailed write-up: Lesson Learned: Graylog JVM Heap Over-Allocation