In this blog post, I want to share a case we worked on a few days ago. I’ll show you how we approached the resolution of a MySQL performance issue and used Percona Monitoring and Management PMM to support troubleshooting. The customer had noticed a linear high CPU usage in one of their MySQL […]Read more
InnoDB keeps hot data in memory on its buffer named InnoDB Buffer Pool. For a long time, when a MySQL instance needed to bounce, this hot cached data was lost and the instance required a warm-up period to perform as well as it did before the service restart.
That is not the case anymore. Newer […]
Continuing on the series of blog posts about MySQL High Availability, today we will talk about stale reads and how to overcome this issue.
Stale reads is a read operation that fetches an incorrect value from a source that has not synchronized an update operation to the value (source Wiktionary).
A practical scenario is when […]
In this blog post, I’ll look at how to execute a MySQL single table Point-In-Time Recovery.
I recently wrote a blog post describing a different way of doing Point-In-Time Recovery (PITR). If you want to know the step by step, please visit the mentioned blog post. Here is a quick summary of the approach:
Restore the backup […]Read more
In this blog, I’ll look at how to do MySQL point in time recovery (PITR) correctly.
Sometimes we need to restore from a backup, and then replay the transactions that happened after the backup was taken. This is a common procedure in most disaster recovery plans, when for example you accidentally drop a table/database or run […]
This blog we describe an issue with MySQL 5.7’s super_read_only feature when used alongside with GTID in chained slave instances.
In MySQL 5.7.5 and onward introduced the gtid_executed table in the MySQL database to store every GTID. This allows slave instances to use the GTID feature regardless whether the binlog option is set or not. Here is […]
In today’s blog, I will show an issue with seconds_behind_master that one of our clients faced when running slave_parallel_workers > 0. We found out that the reported seconds_behind_master from SHOW SLAVE STATUS was lying. To be more specific, I’m talking about bugs #84415 and #1654091.
MySQL will not report the correct slave lag if you have slave_parallel_workers > […]
In this blog post, we will discuss how we can verify if an application transaction executed on the master has been applied to the slaves.
In summary, is a good practice to alleviate the load on the master by doing reads on slaves. It is acceptable in most of the cases to just connect on slaves and […]