Debugging Memory Usage
Debugging memory usage on CentOS 7.
This page describes how to debug MariaDB's memory usage. It uses CentOS 7 but can be applied to other systems as well.
The idea is to employ Google PerfTools: https://gperftools.github.io/gperftools/heapprofile.html
On CentOS :
sudo yum install gperftools service mariadb stop systemctl edit mariadb
This will open an editor.
Add this content and close the file:
[Service] Environment="HEAPPROFILE=/tmp/heap-prof-1" Environment="HEAP_PROFILE_ALLOCATION_INTERVAL=10737418240" Environment="HEAP_PROFILE_INUSE_INTERVAL=1073741824" Environment="LD_PRELOAD=/usr/lib64/libtcmalloc.so.4"
service mariadb start
Then, run the workload. When memory consumption becomes large enough, ruh
ls -la /tmp/heap-prof-*
This should show several files.
Copy away the last one of them:
cp /tmp/heap-prof-1.0007.heap .
pprof --dot /usr/sbin/mysqld heap-prof-1.0007.heap > 7.dot
(Note: this produces a lot of statements like
/bin/addr2line: Dwarf Error: ... . Is this because it cannot find locations from the plugin .so files in mariadbd? Anyhow, this is not a showstopper at the moment)
Then, please send us the 7.dot file.