MultiQueue

Overview

MultiQueue is a feature that allowed SendSage Studio to queue messages to SendSage
Engine more efficiently. This reduces CPU and memory IO overhead.

MultiQueue is disabled by default because it is in beta. When the caveats are removed
this will become the default.

Enabling MultiQueue

1. Set the /var/hvmail/control/studio.use_direct_injection.batch_size
   file equal to the maximum number of messages which Studio should write
   to the same file. For example, to set this limit to 20, run:

     echo 20 > /var/hvmail/control/studio.use_direct_injection.batch_size
   

2. Update the ram-queue’s size
   to be one of the options whose name ends in _multiqueue.
3. Restart Studio’s worker to apply changes:

    svc -t /service/hvmail-studio-worker
    sleep 7
    svstat /service/hvmail-studio-worker
   

Disabling MultiQueue

1. Delete MultiQueue’s configuration file:

    rm -f /var/hvmail/control/studio.use_direct_injection.batch_size
   

2. Update the ram-queue’s size
   to be one of the options whose name does not end in _multiqueue.
3. Restart Studio’s worker to apply changes:

    svc -t /service/hvmail-studio-worker
    sleep 7
    svstat /service/hvmail-studio-worker
   

Caveats

1. Messages will be queued in batches, and some of Engine’s reporting does not differentiate between a message batch
   and the messages in that batch. For example, the hvmail_status command will report each message batch as a
   single message.
2. When SendSage Engine is running at speed capacity with a fully utilized ram-queue, enabling MultiQueue will cause
   Studio will be able to “hog” a larger percentage of the total system capacity compared to non-Studio email sent through
   Engine.