I have known for some times that there is an interesting improvement in MySQL 8.0.17 regarding GTID Crash Safety, but I have not had the time nor the need to look into it before.  When writing my last post (Understanding MySQL Replication "fatal error 1236": [...]), I saw something interesting related to this, and it is now time to cover this on my blog. From my point of view, this change is

You read this right, symbolic links (symlinks) are unsafe in MySQL since at least 8.0.39.  As always, it is a little more complicated than that, but if you are using symbolic links and in certain conditions, you risk a crash.  I think it is important to raise awareness on this, hence this post.

My attention was brought to this via the now private Bug #120156: MySQL 8.0.39/8.0.42

This is a quick one.  My attention was recently brought (thanks Simon) on a relatively recent comment (25 Nov 2025) in Bug #103672 - Binlog compression transaction payload event exceeds max allowed packet :

The underlying server bug was fixed in 8.0.34 in BUG#33588473. The server now falls back to writing the transaction without compression, if the compressed size would

Something changed in MySQL 8.4 related to caching, and it is easy to miss, so it deserves a post.  And a subject adjacent to this is the missing Release Candidate for MySQL 8.4 LTS, with my hope that the next LTS will have a Release Candidate, so I also cover this topic below.

(if you are not interested in Caching and Flushing, you can jump directly to the section about Release Candidate)

I published another article on the Percona Community Blog.  This time, it is about Semi-Synchronous Replication.  You can read the post here:

Question about Semi-Synchronous Replication: the Answer with all the Details

I previously wrote about my motivation to publish on the Percona Community Blog.  Things have not changed: I still believe it is a great community initiative that I want to