CatMQ v2.9.1

Full Changelog: https://github.com/NTDLS/CatMQ/compare/2.9.0...2.9.1

Be sure to check out the NuGet packages: 📦

https://www.nuget.org/packages/NTDLS.CatMQ.Shared
https://www.nuget.org/packages/NTDLS.CatMQ.Server
https://www.nuget.org/packages/NTDLS.CatMQ.Client

New 🎉

• Added a per-queue backoff for failed deliveries.

Changed 😎

• Each queue now runs its delivery loop on a dedicated, named thread (CatMQ.Delivery.<QueueName>) instead of a thread pool thread.
• A MaxMessageAge of zero now means messages never expire, for both queues and dead-letter queues, matching the documented behavior.
• Upgrade note: queues with a dead-letter MaxMessageAge of 00:00:00 will now keep expired messages in the dead-letter queue instead of dropping them. These queues may grow and will need to be drained or purged.

Fixed 🐛

• Fixed thread pool starvation on servers with few cores and multiple queues, where blocked delivery loops could delay delivery replies, enqueues and the web UI.
• Fixed expired messages being silently dropped instead of dead-lettered when the dead-letter MaxMessageAge was zero.
• Fixed messages in a dead-letter queue with a MaxMessageAge of zero expiring as soon as they were loaded for delivery.
• Fixed low throughput with asynchronous delivery: when all delivery slots were full, the delivery thread now wakes as soon as one frees up instead of waiting for its idle timeout.
• Fixed delivery stalls on persistent queues when reloading an empty message buffer, which scanned every deleted message while holding the write lock. Loading now resumes from the last loaded message.
• Fixed delivery stopping while the message buffer was under constant read activity, because removing finished messages and reloading the buffer each tried the write lock only once.