Ok, so now we’re got our InnoDB Cluster a-clustering, MySQL Router a-routing, now we need some disaster to be a-disaster-recovering…

A foreword first.

If you’re looking to use Enterprise Backup to recover a single node and restore that node back into an existing InnoDB Cluster, LeFred takes you through that one nicely here.

Preparing for backup

On our single primary server, the one that allows write, which was ic2/10.0.0.12 in my case:

mysql -uroot -poracle << EOF 
SET sql_log_bin = OFF; 
 create user 'backup'@'%' identified by 'oracle';
 grant all on *.* to 'backup'@'%';
SET sql_log_bin = ON; 
EOF

Let’s create something to backup (if you haven’t already done so of course):

mysqlsh --uri …

Want to setup InnoDB Cluster and be prepared for a Disaster Recovery scenario? Get ready:

Here’s a way to set up InnoDB Cluster using the 3 environments, on Oracle Linux 7.2, 5.7.19 MySQL Commercial Server, MySQL Shell 8.0.3 DMR, MySQL Router. As this is the first blog post for a complete disaster recovery scenario of InnoDB Cluster, we’ll also be installing MySQL Enterprise Backup.

If you’re new to InnoDB Cluster then I’d highly recommend looking at the following to understand how it works and what Group Replication, Shell & Router are.:

• https://dev.mysql.com/doc/refman/5.7/en/mysql-innodb-cluster-production-deployment.html
• …

Well, since working with outdated clusters and upgrade paths that quickly become obsolete, as in my last post, Migrating/importing NDB to Cluster Manager w/ version upgrade. , I wanted to share that we can also use Cluster Manager, mcm, to upgrade NDB Cluster from 7.3 directly to 7.5. So we can start using the mcm new features like autotune that help guide us towards some Cluster tuning, or 7.5 new features like READ_BACKUP or FULLY_REPLICATED tables. …

Various people have complained about Linux swapping unexpectedly on boxes running mysqld, when apparently mysqld was not using all the memory and there was quite a bit of free memory available.

There’s also an article by Jeremy Cole. However, his solution requires a one-line change to mysqld_safe which while it’s small does not work very well if you have to maintain a large number of servers and are using packages asa package upgrade will overwrite the modified file mysqld_safe and then restart mysqld with the unmodified script. This leads to the need to repatch the script and then restart mysqld. Not very helpful.

So I was looking for another solution and came up with this option which basically requires a minor change to /etc/my.cnf and the use of a small shell wrapper script. The change to my.cnf is simply to …