Configuring Multiple Event Loops

To fully utilize the capacity of multi-core CPU architectures, you can configure Momentum for multiple event loops. This configuration enables Momentum to scale so that the overall performance is not limited by a single event-scheduler thread. Instead, a pool of event scheduler instances is created, running in separate threads. Tasks that are performed in the event scheduler thread will now be farmed out to this pool of scheduler instances. These tasks include message reception, message delivery, mail queue maintenance, DNS lookup, and event operations performed by the various modules.

The platforms that support multiple event loops are Red Hat Enterprise Linux 5 (x86_64) and Red Hat Enterprise Linux 6 (x86_64).

Configuring Momentum for multi-core CPUs requires an additional Supercharger license. This license specifies a maximum number of event loops. When configuring an event loop, the concurrency option cannot exceed the licensed number of event loops.

To enable the multiple event loop feature for SMTP and HTTP injection, add the following options to your ecelerity.conf file:

1. Define a new eventloop pool called "events_pool" and set the concurrency (i.e. number of event loops) to 75% of the number of available CPUs.

   eventloop "events_pool" { concurrency = 75%_of_available_CPUs }

2. Associate email delivery with the new eventloop pool by assigning the eventloop name to delivery_pool.

   delivery_pool = "events_pool"

3. Associate mail queues, DNS lookup, and module events with the new eventloop pool by assigning the eventloop name to maintainer_pool.

   maintainer_pool = "events_pool"

4. Associate the SMTP listener with the new eventloop pool by assigning the eventloop name to event_loop inside the listener scope.

   ESMTP_Listener {
     event_loop = "events_pool"
     Listen ":25" {
       Concurrency = 1
     }
     ...
   }
   

5. Associate the HTTP listener with the new eventloop pool by assigning the eventloop name to event_loop inside the listener scope.

   HTTP_Listener {
     event_loop = "events_pool"
      ...
   }
   

After you edit your ecelerity.conf file, you must restart the ecelerity process using /opt/msys/ecelerity/bin/ec_ctl — issuing the ec_console command config reload will not suffice. See ec_ctl.