Clear cgroup configurations

After OceanBase Database is upgraded, the structure of the control group (cgroup) directory may change. Therefore, before you upgrade OceanBase Database, you must delete the original cgroup system directory.

Prerequisites

You have stopped the OBServer node where the cgroup system directory is configured. For more information, see Restart a node.

Procedure

1. Log on as the admin user to the server where the OBServer node resides.

2. Delete the soft link between the installation directory of OceanBase Database and the cgroup system directory.

   [admin@xxx /home/admin/oceanbase]
   $ll cgroup
   lrwxrwxrwx 1 admin admin 29 Dec  8 11:09 cgroup -> /sys/fs/cgroup/cpu/oceanbase/
   
   [admin@xxx /home/admin/oceanbase]
   $ rm -rf cgroup
   

3. Delete the cgroup system directory /sys/fs/cgroup/cpu/oceanbase.

   Files in the cgroup system directory must be recursively deleted from a lower-level directory to an upper-level directory. Therefore, you can create a script file named deletecgroupdir.sh to delete a directory and its subdirectories.

   1. Create a script file, enter related content, and save the script file.

      [admin@xxx /home/admin]$ vim deletecgroupdir.sh
      

      You must enter the following content in the script file:

      #! /bin/bash
      function read_dir(){
              for file in `ls $1`
                      do
                              if [ -d $1"/"$file ]
                                      then
                                              read_dir $1"/"$file
      
                              fi
              done
              string=$1
              echo rmdir $string
              rmdir $string
      }
      # Read the first parameter.
      read_dir /sys/fs/cgroup/cpu/oceanbase
      

   2. Execute the script to delete the cgroup system directory.

      [admin@xxx /home/admin]
      $sudo /bin/bash deletecgroupdir.sh
      

References

Configure cgroups