Increase the maximum number of threads

Elasticsearch uses a number of thread pools for different types of operations. It is important that it is able to create new threads whenever needed. Make sure that the number of threads that the Elasticsearch user can create is at least 4096.

To apply this limit, use the system settings configuration methods for your install type. For example, using ulimit and editing /etc/security/limits.conf for .tar.gz archives, or throughsystemd overrides when you need to change defaults on package-based installations.

The package distributions when run as services under systemd will configure the number of threads for the Elasticsearch process automatically. No additional configuration is required.