How to Rotate the Database Logs when Greenplum is Running

Products

• VMware Tanzu Greenplum

Issue/Introduction

This article provides provide information to help rotate the logfile when the database is up and running.

Note- Please verify the script on a test cluster , before running it on production .

 

Environment

Resolution

Function "pg_rotate_logfile" is a handy little tool to rotate the database log when the database is up and running.

Below example helps you understand the function "pg_rotate_logfile" in practice.

• Check the current log in the directory:

  flightdata=# select pg_ls_dir('pg_log') order by 1 desc;
       
               pg_ls_dir
      ----------------------------
       startup.log
       gp_era
       gpdb-2013-04-22_131246.csv
       gpdb-2013-04-22_000000.csv
  [.....]
  [.....]
  Use pg_rotate_logfile to switch logfile and write to a new logfile
  flightdata=#  select pg_rotate_logfile();
       pg_rotate_logfile
      -------------------
       t
      (1 row)

• Rechecking the current log in the directory using "pg_ls_dir"

  flightdata=# select pg_ls_dir('pg_log') order by 1 desc;
               pg_ls_dir
      ----------------------------
       startup.log
       gp_era
       gpdb-2013-04-22_131722.csv
       gpdb-2013-04-22_131246.csv
       gpdb-2013-04-22_000000.csv
  [.....]
  [.....]

  Alternatively, you can use/tune parameter "log_rotation_size" to rotate the logfile when they reach a certain size , by default the size is zero which means all the contents remain on a single file.

Additional Information

+ Environment:

Pivotal Greenplum Database (GPDB) all versions