Code review comment for lp:~tplavcic/percona-server/bld-212-5.6-tokudb

There is an issue in Jira BLD-246:

  https://jira.percona.com/browse/BLD-246

PZ discovered that is Percona Server is installed and running without jemalloc prior to the installation of TokuDB (along with jemalloc dependency) then ps_tokudb_admin fails to load the plugin.

The solution that PZ recommend is the safest way to handle it. Have ps_tokudb_admin check to see if mysqld is running without jemalloc underneath. If that condition is true, then stop prior to installation of the plug-in with a message indicating a restart is required.

During restart, the updated mysqld_safe will detect and load the underlying jemalloc automatically and the ps_tokudb_admin --enable can proceed.

There is a command in the Jira issue that will check for jemalloc running underneath mysqld:

  grep -c jemalloc /proc/$(cat {path}/mysqld.pid)/environ

If this returns 0 then the process needs to stop with the restart notification.