Add documentation that ps-admin removes jemalloc and THP settings on TokuDB uninstall

General

Escalation

General

Escalation

Description

This is done regardless of what were the settings before TokuDB installation and if user want to keep them or not.

Emails:

DBennett:
 Is this by design? 
 
 One (easiest) option would be to leave jemalloc and THP as is and provide options allowing the user to reconfigure those separately. We could also provide messaging on TokuDB deinstallation letting the user know about the current state of these settings and what to do next.
 
 Another, more involved solution, would be to capture the previous state of the system in metadata stored in my.cnf comments and then reinstate the previous configuration on uninstall.
 
 On Sat, Jun 16, 2018 at 3:55 PM, Peter Zaitsev <pz@percona.com> wrote:
 Hi,
 
 I noticed TokuDB de-installation seems to remove jemalloc ENABLES huge pages etc
 
 Is this ALWAYS done or are we restoring it to the previous settings which were done before the run ?
 
 root@skullnuc:/var/lib/mysql# ps-admin --disable tokudb
 ps-admin: option '--disable' is ambiguous; possibilities: '--disable-tokudb' '--disable-mysqlx' '--disable-pam-compat' '--disable-pam' '--disable-audit' '--disable-qrt' '--disable-rocksdb' '--disable-tokubackup'
 root@skullnuc:/var/lib/mysql# ps-admin --disable-tokudb
 Checking transparent huge pages status on the system...
 INFO: Transparent huge pages are currently disabled on the system.
 
 Checking if THP_SETTING variable is set to never or madvise in /etc/default/mysql...
 INFO: Variable THP_SETTING is set in /etc/default/mysql.
 
 Checking if LD_PRELOAD variable is set for libjemalloc.so.1 in /etc/default/mysql...
 INFO: Variable LD_PRELOAD for libjemalloc.so.1 is set in /etc/default/mysql.
 
 Checking if LD_PRELOAD variable is set for libHotBackup.so in /etc/default/mysql...
 INFO: Variable LD_PRELOAD for libHotBackup.so is not set in /etc/default/mysql.
 
 Checking TokuDB engine plugin status...
 INFO: TokuDB engine plugin is installed.
 
 Checking TokuBackup plugin status...
 INFO: TokuBackup plugin is not installed.
 
 Removing THP_SETTING variable from /etc/default/mysql
 INFO: Successfully removed THP_SETTING variable from /etc/default/mysql
 
 Removing LD_PRELOAD option from /etc/default/mysql
 INFO: Successfully removed LD_PRELOAD option for libjemalloc.so.1 and libHotBackup.so from /etc/default/mysql
 
 Uninstalling TokuDB engine plugin...
 INFO: Successfully uninstalled TokuDB engine plugin.

Environment

None

Attachments

tokudb_test.txt

06 Sep, 2018

Activity

Show:

Lalit Choudhary

September 6, 2018 at 9:32 AM

Tested with 5.7.22. , centos7

Before tokudb install:(OS default)

[root@localhost ~]# cat /sys/kernel/mm/transparent_hugepage/enabled
[always] madvise never

After enabling TokuDB

[root@localhost ~]# cat /etc/sysconfig/mysql
LD_PRELOAD=/usr/lib64/libjemalloc.so.1
THP_SETTING=never
[root@localhost ~]# cat /sys/kernel/mm/transparent_hugepage/enabled
always madvise  [never]

After Disabling TokuDB:

[root@localhost ~]# cat /etc/sysconfig/mysql
[root@localhost ~]# cat /sys/kernel/mm/transparent_hugepage/enabled
always madvise [never]
[root@localhost ~]#

In this case, THP settings not restoring to the original default state(Before tokudb install:(OS default))

It will be good to add more details about this in the removing_tokudbdocumentation, as well as this request can be an improvement request, to show current settings message while disabling the tokudb.

https://www.percona.com/doc/percona-server/LATEST/tokudb/removing_tokudb.html

Resize issue view side panel

Done

Details

Assignee

patrick.birch

Reporter

Tomislav Plavcic

Labels

Time tracking

2h 30m logged

Priority

Medium

Created June 18, 2018 at 7:03 AM

Updated March 6, 2024 at 1:07 PM

Resolved July 17, 2020 at 10:33 AM