If there is less than 10% of free heap memory available during publication of item then Tigase pubsub component will trigger Garbage Collection and it there is still very little amount of free memory will slow down delivery of notifications for published items (waiting about 1 second before continuing).
If you have assigned a lot of memory to Tigase XMPP Server or in your case this delay is not acceptable you can adjust it by pubsub component properties:
- setting
pubsub-high-memory-usage-level
to percentage of heap memory accepted as near OOM state - setting
pubsub-low-memory-delay
to number of milliseconds to wait to throttle delivery of notifications
pubsub () { pubsub-high-memory-usage-level = 95 pubsub-low-memory-delay = 100 }