Maximum Queue Size

The eFTL server maintains a message queue for each eFTL client subscription. These queues hold messages for transfer to clients. If many subscriptions are present, and clients frequently disconnect, then queue growth can strain memory resources in the eFTL server. Maximum Queue Size limits queue growth to conserve memory.

When distributing a message to a queue would overflow this maximum, two behaviors are possible:
  • If the channel is not configured for persistence, the queue discards the oldest messages to make room for new messages.
  • If the channel is configured for persistence, the queue discards the new message. The persistence store redelivers discarded messages to the queue at a later time.

The default maximum is 100 messages. You can decrease this value to reduce memory requirements even further.