WorkerThreads

Sets the default number of worker threads for listeners on epoll-enabled systems.

This parameter applies to imtcp: TCP Syslog Input Module.

Name:

WorkerThreads

Scope:

module

Type:

integer

Default:

module=2

Required?:

no

Introduced:

8.2504.0

Description

The WorkerThreads parameter defines the default number of worker threads for all imtcp listeners. This setting applies only on epoll-enabled systems. If epoll is unavailable, imtcp will always run in single-threaded mode, regardless of this setting.

Default value: 2 Allowed values: 1 (single-threaded) to any reasonable number (should not exceed CPU cores).

Behavior and Recommendations

  • If set to 1, imtcp operates in single-threaded mode, using the main event loop for processing.

  • If set to 2 or more, a worker pool is created, allowing multiple connections to be processed in parallel.

  • Setting this too high can degrade performance due to excessive thread switching.

  • A reasonable upper limit is the number of available CPU cores.

Scope and Overrides - This is a module-level parameter, meaning it sets the default for all imtcp listeners. - Each listener instance can override this by setting the workerthreads listener parameter.

Example Configuration The following sets a default of 4 worker threads for all listeners, while overriding it to 8 for a specific listener:

module(load="imtcp" WorkerThreads="4")  # Default for all listeners

input(type="imtcp" port="514" workerthreads="8")  # Overrides default, using 8 workers

If WorkerThreads is not explicitly set, the default of 2 will be used.

Module usage

module(load="imtcp" workerThreads="4")

See also

See also imtcp: TCP Syslog Input Module.

Support: rsyslog Assistant | GitHub Discussions | GitHub Issues: rsyslog source project

Contributing: Source & docs: rsyslog source project

© 2008–2025 Rainer Gerhards and others. Licensed under the Apache License 2.0.