[pgpool-hackers: 2906] Re: segmentation fault in pgpool child

[Tatsuo Ishii]

Usama,

Thanks for the report. I will look into this.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

> Hi Ishii-San
> 
> Pgpool-II child process is terminating with segmentation fault and the
> issue seems to be similar to the one you fixed recently with always_master
> mode.
> 
> The crash is happening in the  MASTER_CONNECTION() macro
> 
> pool_do_auth() line 78
> protoMajor = MASTER_CONNECTION(cp)->sp->major;
> 
> 
> Steps to reproduce
> ====
> 1- point the backend0 to slave PostgreSQL node and backend1 to the master
> PostgreSQL node
> 
> backend_hostname0 = slave_PG
> backend_hostname1 = master_PG
> 
> 2- disable health check
> health_check_period = 0
> 
> 3- disable failover on backend error
> fail_over_on_backend_error = off
> 
> 4- shutdown the slave PostgreSQL server.
> 
> 5- start Pgpool
> 
> 6- No try connecting to Pgpool
> 
> ]$ bin/psql postgres -p 9999 -U pgpool
> psql: server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> 
> 
> Related pgpool logs
> ===========
> 2018-08-01 17:17:46: pid 4422: DEBUG:  I am 4422 accept fd 7
> 2018-08-01 17:17:46: pid 4422: LOCATION:  child.c:2187
> 2018-08-01 17:17:46: pid 4422: DEBUG:  reading startup packet
> 2018-08-01 17:17:46: pid 4422: DETAIL:  application_name: psql
> 2018-08-01 17:17:46: pid 4422: LOCATION:  child.c:588
> 2018-08-01 17:17:46: pid 4422: DEBUG:  reading startup packet
> 2018-08-01 17:17:46: pid 4422: DETAIL:  Protocol Major: 3 Minor: 0
> database: postgres user: pgpool
> 2018-08-01 17:17:46: pid 4422: LOCATION:  child.c:630
> 2018-08-01 17:17:46: pid 4422: DEBUG:  creating new connection to backend
> 2018-08-01 17:17:46: pid 4422: DETAIL:  connecting 0 backend
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_connection_pool.c:837
> 2018-08-01 17:17:46: pid 4422: LOG:  failed to connect to PostgreSQL server
> on "127.0.0.1:5432", getsockopt() detected error "Connection refused"
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_connection_pool.c:660
> 2018-08-01 17:17:46: pid 4422: LOG:  failed to create a backend 0 connection
> 2018-08-01 17:17:46: pid 4422: DETAIL:  skip this backend because because
> fail_over_on_backend_error is off and we are in streaming replication mode
> and node is standby node
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_connection_pool.c:888
> 2018-08-01 17:17:46: pid 4422: DEBUG:  creating new connection to backend
> 2018-08-01 17:17:46: pid 4422: DETAIL:  connecting 1 backend
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_connection_pool.c:837
> 2018-08-01 17:17:46: pid 4422: DEBUG:  attempting to negotiate a secure
> connection
> 2018-08-01 17:17:46: pid 4422: DETAIL:  sending client->server SSL request
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_ssl.c:77
> 2018-08-01 17:17:46: pid 4422: DEBUG:  pool_flush_it: flush size: 8
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_stream.c:614
> 2018-08-01 17:17:46: pid 4422: DEBUG:  pool_read: read 1 bytes from backend
> 1
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_stream.c:191
> 2018-08-01 17:17:46: pid 4422: DEBUG:  attempting to negotiate a secure
> connection
> 2018-08-01 17:17:46: pid 4422: DETAIL:  client->server SSL response: N
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_ssl.c:89
> 2018-08-01 17:17:46: pid 4422: DEBUG:  attempting to negotiate a secure
> connection
> 2018-08-01 17:17:46: pid 4422: DETAIL:  server doesn't want to talk SSL
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_ssl.c:105
> 2018-08-01 17:17:46: pid 4422: DEBUG:  pool_flush_it: flush size: 82
> 2018-08-01 17:17:46: pid 4422: LOCATION:  pool_stream.c:614
> 2018-08-01 17:17:46: pid 4421: DEBUG:  reaper handler
> 2018-08-01 17:17:46: pid 4421: LOCATION:  pgpool_main.c:2411
> 2018-08-01 17:17:46: pid 4421: WARNING:  child process with pid: 4422 was
> terminated by segmentation fault
> 2018-08-01 17:17:46: pid 4421: LOCATION:  pgpool_main.c:2462
> 
> backtrace (generated from V3_7_STABLE head)
> =========
> #0  0x000000000041d683 in pool_do_auth (frontend=frontend at entry=0x22dd818,
> cp=cp at entry=0x7f2b29382358) at auth/pool_auth.c:78
> #1  0x0000000000424ccf in connect_backend (sp=sp at entry=0x22df768,
> frontend=frontend at entry=0x22dd818) at protocol/child.c:911
> #2  0x0000000000426c9f in get_backend_connection (frontend=0x22dd818) at
> protocol/child.c:2352
> #3  do_child (fds=fds at entry=0x22d5710) at protocol/child.c:338
> #4  0x0000000000408b85 in fork_a_child (fds=0x22d5710, id=0) at
> main/pgpool_main.c:611
> #5  0x000000000040e88b in PgpoolMain (discard_status=discard_status at entry=1
> '\001', clear_memcache_oidmaps=clear_memcache_oidmaps at entry=0 '\000')
>     at main/pgpool_main.c:367
> #6  0x0000000000407071 in main (argc=<optimized out>, argv=<optimized out>)
> at main/main.c:318
> 
> 
> 
> Thanks
> Best Regards
> Muhammad Usama