Very Large segment log

Products

• VMware Tanzu Greenplum

Issue/Introduction

One of the segment logs is 10 times bigger than on other segments

du -sh /data/primary/gpseg8/pg_log/gpdb-2021-04-30_000000.csv
27G gpdb-2021-04-30_000000.csv
du -sh /data/primary/gpseg4/pg_log/gpdb-2021-04-30_000000.csv
2.0G gpdb-2021-04-30_000000.csv

Environment

Product Version: 5.28

Resolution

- comparing postgresql.conf from big log segment to other segment we found 2 extra GUCs were added.

diff gpseg4_postgresql.conf gpseg8_postgresql.conf
597a598,601
> Debug_persistent_print=on
> Debug_persistent_print_level=LOG
638c642
< [gpadmin@ddlgpsprd001 pg_log]$
---
> [gpadmin@ddlgpsprd001 pg_log]
\ No newline at end of f

- checking other servers with gpconfig we found it was primary and mirror segment that have 2 extra GUCs

[gpadmin@mdw ~]$ gpconfig -s Debug_persistent_print --file-compare | grep "value: on"
[context: 8] [dbid: 10] [name: Debug_persistent_print] [value: on | file: on]
[context: 8] [dbid: 298] [name: Debug_persistent_print] [value: on | file: on]

- These 2 GUCs print much more debugging information in a log file.
- The GUCs were removed from the postgresql.conf file after confirming that this information is not needed anymore.
- The database was then restarted.
- The log file size on the segment was then the same other segments.