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From: zam bak <zam6ak@gmail.com>
Date: Thu, 27 Nov 2025 13:55:07 -0500
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 <CAEy4EGWmgs3oQ2k-0rR3gvh3FQFnN9dajEtakBfxDJeyYiDBgA@mail.gmail.com>
Subject: "buffer overflow detected" when running SHOW POOL_STATUS
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Hello

I am using the latest pgpool-II v4.6.4 on Rocky Linux v10.1
(installation via RPMs) with PostgreSQL 18 (one primary, one replica,
streaming replication)
When attempting to run POOL_STATUS command, either as SQL or via pcp,
I am getting "buffer overflow detected" in the log.
Here are the contents of the log from both SQL and pcp commands:

1)
sudo -u postgres pcp_pool_status -w -v -h localhost -p 9898 -U postgres

2025-11-27 13:30:19.298 [4486]: [3-1] user=3D[No Connection],db=3D[No
Connection],app=3Dpcp_main LOG:  forked new pcp worker, pid=3D4495
socket=3D7
2025-11-27 13:30:19.298 [4486]: [4-1] user=3D[No Connection],db=3D[No
Connection],app=3Dpcp_main LOCATION:  pcp_child.c:327
*** buffer overflow detected ***: terminated
2025-11-27 13:30:20.315 [4486]: [5-1] user=3D[No Connection],db=3D[No
Connection],app=3Dpcp_main LOG:  PCP process with pid: 4495 exits with
status 134 by signal 6
2025-11-27 13:30:20.315 [4486]: [6-1] user=3D[No Connection],db=3D[No
Connection],app=3Dpcp_main LOCATION:  pcp_child.c:394

2)
sudo -u postgres psql -w -h localhost -p 9999 -U postgres -c "SHOW POOL_STA=
TUS"

2025-11-27 13:31:34.385 [4390]: [1-1]
user=3Dpostgres,db=3Dpostgres,app=3Dpsql LOG:  DB node id: 0 backend pid:
10166 statement: SELECT pg_catalog.version()
2025-11-27 13:31:34.385 [4390]: [2-1]
user=3Dpostgres,db=3Dpostgres,app=3Dpsql LOCATION:
pool_proto_modules.c:3803
*** buffer overflow detected ***: terminated


And here is my pgpool.conf file (only changed lines - diff compared to
pgpool.conf.sample)
diff --unchanged-line-format=3D --old-line-format=3D
--new-line-format=3D'%L' pgpool.conf.sample pgpool.conf

listen_addresses =3D '*'
unix_socket_directories =3D '/var/run/pgpool'
pcp_socket_dir =3D '/var/run/pgpool'
serialize_accept =3D on
backend_hostname0 =3D '192.168.68.104'
backend_port0 =3D 5432
backend_weight0 =3D 1
backend_data_directory0 =3D '/data/pgdata/18'
backend_flag0 =3D 'ALWAYS_PRIMARY'
backend_application_name0 =3D 'primary'
backend_hostname1 =3D '192.168.68.105'
backend_port1 =3D 5432
backend_weight1 =3D 1
backend_data_directory1 =3D '/data/pgdata/18'
backend_flag1 =3D 'DISALLOW_TO_FAILOVER'
backend_application_name1 =3D 'replica_1'
num_init_children =3D 96
max_pool =3D 2
child_life_time =3D 0
log_line_prefix =3D '%m [%p]: [%l-1] user=3D%u,db=3D%d,app=3D%a '   #
printf-style string to output at beginning of each log line.
log_connections =3D off
log_disconnections =3D off
log_per_node_statement =3D on
log_standby_delay =3D 'always'
log_error_verbosity =3D verbose          # terse, default, or verbose messa=
ges
log_filename =3D 'pgpool-01-%a.log'
write_function_list =3D
'currval,lastval,nextval,setval,public.upgrade_.*,upgrade_.*,public.update_=
.*,update_.*,public.selsert_.*,selsert_.*,public.purge_.*,purge_.*,public.p=
rocess_.*,process_.*,public.move_.*,move_.*,public.merge_.*,merge_.*,public=
.mark_.*,mark_.*,billing.can_ahs_claim_charge,billing.can_ahs_apply_.*'
statement_level_load_balance =3D on
sr_check_period =3D 5s
sr_check_user =3D 'pgpool_monitor'
delay_threshold_by_time =3D 500ms
health_check_period =3D 10
health_check_timeout =3D 30
health_check_user =3D 'pgpool_monitor'
health_check_max_retries =3D 10
failover_on_backend_error =3D off
check_temp_table =3D trace