In the last weeks / months, I have been working on understanding / improving MySQL startup with many tables.  I already wrote five posts on the subject, they are listed below.  In this post, I use the knowledge we gained in the previous two posts to show the interest of tuning InnoDB Tablespace Duplicate Check Threads, making startup 30% in one case (2:28 vs. 3:33) and 5% in

In the last weeks / months, I have been working on understanding / improving MySQL startup with many tables.  I already wrote four posts on the subject, they are listed below.  In this post, I use the system analysis of the previous post to revisit the light optimization on EBS volumes.  With this analysis, I am able to determine why the previous tests did not show

In the last weeks / months, I have been working on understanding / improving MySQL startup with many tables.  I already wrote two posts on the subject, the links are below.  So far, I did not share what brought my attention to this, and it is the subject of this post.  Also, and because it is related, I come back to the optimization / contribution I already made on

In this blog post, we will explore how network partitions impact group replication and the way it detects and responds to failures. In case you haven’t checked out my previous blog post about group replication recovery strategies, please have a look at them for some insight. Topology: [crayon-674f2fda5005b513231798/] Scenario 1: One of the GR nodes […]

I have been scratching my head about MySQL startup for some time.  There is much to say about this, and many other posts will probably follow.  For now, it is enough to know that with many tables (millions) the startup of MySQL 8.0+ (including 8.0, 8.4 and 9.0) is suboptimal (to say the least).  With very little changes, I was able to speed it up, from 2:39 to 1:09 (1 minute and 9

At Percona, we have always prioritized database performance as a critical factor in selecting database technologies. Recently, we have observed a concerning trend in the community edition of MySQL, where performance appears to be declining across major releases, specifically MySQL versions 5.7, 8.0, and 8.4. If you’re interested in learning more about these observations, we […]

In MySQL 8.0 we introduced a totally new design for InnoDB REDO Log management. The main difference was about implementing a lock-free solution for user threads, and use dedicated REDO threads for all background IO write work.

for more details, see an excellent and very detailed article by Pawel : https://dev.mysql.com/blog-archive/mysql-8-0-new-lock-free-scalable-wal-design/

However, over a time we also added an option to let users to switch REDO threads=OFF to enforce REDO log processing efficiency in some particular cases. Unfortunately this feature created a lot of confusions for MySQL users, and many ones interpreted this in different ways, providing different and sometimes opposite advices, etc..

My main advice will be always : test each feature yourself and within your …

At Percona, we monitor our users’ needs and try to accommodate them. One aspect we monitor is the MySQL version distribution/utilization. Observing that, we identified a very interesting trend: the lack of migration from 5.7 to 8.x, or better yet, the need of many to remain on 5.7.  That observation has triggered several actions from […]

To be honest, the comparison between the two MySQL distributions is not something that excited me a lot. Mainly because from my MySQL memories, I knew that there is not a real difference between the two distributions when talking about the code base.To my knowledge the differences in the enterprise version are in the additional […]

In my previous article, Comparisons of Proxies for MySQL, I showed how MySQL Router was the lesser performing Proxy in the comparison. From that time to now, we had several MySQL releases and, of course, also some new MySQL Router ones.Most importantly, we also had MySQL Router going back to being a level 7 proxy […]