Recommended Java memory settings

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The memory allocated to the Looker application is specified in the Looker startup script.

You can download the latest startup script, looker, at this GitHub repo. When you download the startup script, move it into the same directory as the looker.jar file (generally /home/looker/looker). For more information, see the Installing the Looker application documentation page.

The startup script automatically determines how much java memory to allocate to Looker. However, if you would like to customize this value manually, you can follow these instructions.

Changing Looker's memory allocation

To change the memory allocated to Looker, edit these lines for Java heap and metaspace memory allocation in the startup script:

JAVAMEM="2300m"
METAMEM="800m"

Then, restart the application:

./looker restart

For smaller instances dedicated to Looker, the memory allocated should be approximately two thirds of the available memory. On larger instances this ratio can be increased.

If too much memory is allocated:

  • Looker may fail to start
  • The system generally may suffer performance issues

If too little memory is allocated:

  • Looker may fail to start
  • Looker specifically may suffer performance issues

EC2 instance types

The following table lists the recommended memory settings for a number of common Amazon EC2 instance sizes:

Instance Type Total System Memory JAVAMEM METAMEM
mx.large 7500m 3600m 800m
mx.xlarge 15000m 9000m 1000m
mx.2xlarge 30000m 20000m 1000m
mx.4xlarge 60000m 46000m 1000m