pg_cgroup

A PostgreSQL extension to manage cgroup (Control Group).

Overview

pg_cgroups provides set of SQL-callable functions to manage cgroup on Linux OS. pg_cgroups requires user to create a cgroup for PostgreSQL server in advance. Using pg_cgroup you can both create/delete/set cgroups and classify pids with in the cgroup of PostgreSQL server.

GUC Parameter

• pg_cgroup.cgroup_name (text)
  • The name of cgroup of which owner is the user who was used for initdb.

Example

Installation

You can install pg_cgroup extension in similar way as other PostgreSQL extensions except for requiring libcgroup-devel package.

1. Get libcgroup-devel package

$ sudo yum -y libcgroup-devel

2. Get pg_cgroup source code

$ git clone git@github.com:MasahikoSawada/pg_cgroup.git

3. Build and Install

$ make USE_PGXS=1
$ sudo make USE_PGXS=1 install

Setup

1. Create cgroup for PostgreSQL with definition of user and group

$ cgcreate -g cpu,memory,disk:pgsql -t postgres -a postgres

2. Configuration fo pg_cgroup

$ vi /path/to/postgresql.conf
shared_preload_libraries = 'pg_cgroup'
pg_cgroup.cgroup_name = 'pgsql'

3. Start PostgreSQL Server
4. Create EXTENSION

$ psql -c 'CREATE EXTENSION pg_cgroup'

Usage

• Create new resource group of cpu controller

=# SELECT create_resource_group('test_cg', 'cpu');
 create_resource_group
-----------------------
 t
(1 row)

Now you can see the created new cgroup by using lscgroup or whatever you'd like to use as follows.

$ lscgroup | grep pgsql
cpu,cpuacct:/pgsql/
cpu,cpuacct:/pgsql/test_cg

• Set parameter of cpu cgroup

=# SELECT set_resource_value('test_cg', 'cpu', 'cpu.cfs_quota_us', 50000);
 set_resource_value
--------------------
 t
(1 row)

Test Platforms

Category	Module Name
OS	CentOS 7.4
DBMS	PostgreSQL 10
Library	libcgroup 0.41-13

Copyright

Copyright © 2018- Masahiko Sawada

License

The PostgreSQL License. (same as BSD License)