Is Keycloak experiencing memory leak?

Question

i'm using Keycloak as Identity Manager for the solution i'm working on and in the last months i started experiencing periodically an out of memory error after aproximatly two weeks.

Uncaught server error: java.lang.OutOfMemoryError:Java heap space

I tried different version of keycloak from 13 to 15 but it doesnt seem to make any difference. I started investigating in a docker environment where i only run keycloak and postgres and leave everything idle.

This is the docker-compose.yml file i used to setup the environment:

version: '3'

services:

  postgres:
      image: postgres:14.1
      environment:
        POSTGRES_DB: keycloak
        POSTGRES_USER: postgres
        POSTGRES_PASSWORD: password
        
  keycloak:
      image: jboss/keycloak:15.1.0
      environment:
        DB_VENDOR: POSTGRES
        DB_ADDR: postgres
        DB_DATABASE: keycloak
        DB_USER: postgres
        DB_SCHEMA: public
        DB_PASSWORD: password
        KEYCLOAK_USER: admin
        KEYCLOAK_PASSWORD: password
      ports:
        - 8080:8080
      depends_on:
        - postgres

In the meantime i also launched a standalone container of Keycloak not persisting on Postgres.

I left the containers idle and started monitoring the memory required by Keycloak, these are the results:

Time	Keycloak + Postgres	Keycloak
11:50	630 MB	640 MB
11:55	630.1 MB	645 MB
12:00	630.2 MB	646.5 MB
12:10	630.3 MB	653 MB
12:30	630.6 MB	654.5 MB
12:40	630.7 MB	655.1 MB
14:30	631 MB	655.5 MB

I know the "leak" is almost inconsistent... any ideas on how i could verify if this is actually a leak and in case it is if it is responsible for keycloak out of memory error after weeks of execution? Anyway thanks for your help.

UPDATE

As suggested i modified docker compose file specifying memory reservation and limit for keycloak and postgres services as follows:

version: '3'

services:

  postgres:
      image: postgres:14.1
      environment:
        POSTGRES_DB: keycloak
        POSTGRES_USER: postgres
        POSTGRES_PASSWORD: password
      deploy:
        resources:
          limits:
            memory: 2G
          reservations:
            memory: 1G
        
  keycloak:
      image: jboss/keycloak:15.1.0
      environment:
        DB_VENDOR: POSTGRES
        DB_ADDR: postgres
        DB_DATABASE: keycloak
        DB_USER: postgres
        DB_SCHEMA: public
        DB_PASSWORD: password
        KEYCLOAK_USER: admin
        KEYCLOAK_PASSWORD: password
      ports:
        - 8080:8080
      depends_on:
        - postgres
      deploy:
        resources:
          limits:
            memory: 1G
          reservations:
            memory: 650M

To monitor memory usage i used docker stats command, with system in idle the memory usage of keycloak container keeps slightly growing over time.

Is Keycloak experiencing memory leak?

0 Answers