A few thousand gcache.page.* files in a Percona
XtraDB Cluster (PXC) data directory is not something you see
every day. We came across a case where these files had been
accumulating over time and slowly consuming disk space. So, let’s
dig into what happened.
At first glance, it looked like GCache had simply stopped cleaning itself up. The investigation started by answering two simple questions: when did the files start appearing, and what changed in the cluster at that time?
Finding the starting point
The oldest files showed the issue started on July 9.
[hostx] percona@hostx: ~ $ ls -lh /var/lib/mysql/mysql-data/gcache.page.* -rw-r----- 1 mysql mysql 128M Jul 9 21:42 /var/lib/mysql/mysql-data/gcache.page.000000 -rw-r----- 1 mysql mysql 128M Jul 9 21:42 /var/lib/mysql/mysql-data/gcache.page.000001 -rw-r----- 1 mysql mysql 128M Jul 9 21:42 /var/lib/mysql/mysql-data/gcache.page.000002 ... …[Read more]