Author - James Lawrie

Setting innodb_open_files Higher Than open_files_limit

MySQL innodb_open_files open_file_limit settings

The settings of MySQL configuration variables have a fundamental impact on the performance of your database system. Sometimes it can be a little tricky to predict how changing one variable can affect others, and especially when dealing with cases like the one I’ll describe in this post, where the outcome is not very intuitive. […]

Read more

Caveats With pt-table-checksum Using Row-Based Replication, and Replication Filters

pt-table-checksum row based replication caveat

As per the documentation, pt-table-checksum is a tool to perform online replication consistency checks by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master.
The master and each slave insert checksums into the percona.checksums table, and these are later compared for differences. It’s fairly obvious that […]

Read more

How to Fix ProxySQL Configuration When it Won’t Start

restart ProxySQL config

With the exception of the three configuration variables described here, ProxySQL will only parse the configuration files the first time it is started, or if the proxysql.db file is missing for some other reason.
If we want to change any of this data we need to do so via ProxySQL’s admin interface and then save them […]

Read more

Using ProxySQL to connect to IPv6-only databases over IPv4

connect to ipv6 database from ipv4 application using proxysql

It’s 2018. Maybe now is the time to start migrating your network to IPv6, and your database infrastructure is a great place to start. Unfortunately, many legacy applications don’t offer the option to connect to MySQL directly over IPv6 (sometimes even if passing a hostname). We can work around this by using ProxySQL’s IPv6 […]

Read more