SaunaFS 5.4.0

[uristdwarf]

Hey everyone!

This release is rather small in detailed features and fixes, mostly because most of it consists of refactoring, mainly for multi-master. However there are some notable improvements in chunkserver performance. We were planning to have this out last week, but due to an issue where all of our PRs started failing on Github actions, we decided to postpone it until we found out what the issue was and whether it was related to the commits in the release (turns out that one of our tests hung when GH actions runner ran out of space).

• Option to configure chunkserver buffer size: The new option MAX_BUFFERS_POOL_SIZE_MB in the chunkserver allows you to tweak the performance/memory consumption. Increasing it can increase performance, but also increases memory consumption. While decreasing it will lower memory usage, but decrease performance potentially. You'll have to tweak this to find a good balance.
• Improvements to replica writes: Previously the chunkserver was not reusing the connections when making chained writes, causing more latency than necessary because of the need to recreate the connections.
• General improvements to cluster performance: This was done by prioritizing certain operations that block parts of the system (replication, opening files) in the chunkserver.
• Improved .saunafs_path_by_inode consistency: Sometimes, when trying to read the path from this file, the operation would get blocked and completely freeze the application.
• uRaft stability improvements: Should hopefully prevent the issue found in URAFT big problem today - SAUNAFS frozen because all 4 uraft nodes had blocked_promote=1 and no-one was the leader! #576
• Improvements in the client library on Windows

That I believe pretty much covers it. As usual, please report any bugs you find.

The SaunaFS Team

[uristdwarf]

Full changelog: https://github.com/leil-io/saunafs/releases/tag/v5.4.0