Skip to main content


eventloop — define a pool of event loops to enable multiple event loop configuration


**Configuration Change. ** This option is available as of version 3.6.


In order to use this option you must have a "Supercharger" license. This license specifies a maximum number of event loops. When configuring an event loop, the concurrency option in the eventloop scope cannot exceed the licensed number of event loops. For more information see “Configuring for Multiple Event Loops in Momentum 3.6”.

Use this scope to define a pool of event loops to create a multiple event loop configuration. This eventloop is then associated with specific tasks such as SMTP reception as shown in the following example:

threadpool "accept" {
  concurrency = 1

eventloop "pool" {
  concurrency = 10

delivery_pool = "pool"
maintainer_pool = "pool"

esmtp_listener {
  event_loop = "pool"

  listen ":25" {
    concurrency = 1
    pool_name = "accept"

In general we recommend defining only one eventloop pool. The only option valid in the eventloop scope is concurrency. Set the concurrency option to a value equal to approximately 75% of the total number of CPUs in the system. If the value of the concurrency option exceeds the licensed number of event loops you will see an error message in the log file such as the following:

[Wed 19 Jun 2013 11:02:47] <0x29b7510> Event loop license violation
[Wed 19 Jun 2013 11:02:47] <0x29b7510> Invalid license [Event Loop
[Wed 19 Jun 2013 11:02:47] <0x29b7510> License machine mismatch

In the preceding code an event loop pool is defined and this pool is associated with an SMTP listener, SMTP delivery and a maintainer threadpool. The delivery_pool option handles threading for email delivery, the event_loop option inside the listener scope handles threading for email reception and the maintainer_pool option handles threading for other operations.


An eventloop cannot be defined at runtime and its concurrency cannot be changed at runtime. Changing these options requires restarting the ecelerity process—issuing the ec_console command config reload will not suffice.


eventloop is valid in the global scope.

See Also

Was this page helpful?