[pgpool-general: 9124] Re: Another segmentation fault

[Emond Papegaaij]

This weekend we've seen another series of segmentation faults. The
backtraces are different, but I still suspect they are related. Below is
some information from the core dump:
#0  pool_search_relcache (relcache=0x7f79e74e5fd8, backend=0x7f79e74e1168,
table=0x55fa1085df27 "version") at utils/pool_relcache.c:155
#1  0x000055fa10733aeb in Pgversion (backend=0x7f79e74e1168) at
protocol/pool_pg_utils.c:731
#2  0x000055fa10748850 in Parse (frontend=0x55fa123a7768,
backend=0x7f79e74e1168, len=30, contents=0x55fa123ae798 "") at
protocol/pool_proto_modules.c:1326
#3  0x000055fa1074d23d in ProcessFrontendResponse (frontend=0x55fa123a7768,
backend=0x7f79e74e1168) at protocol/pool_proto_modules.c:2833
#4  0x000055fa10741b99 in read_packets_and_process
(frontend=0x55fa123a7768, backend=0x7f79e74e1168, reset_request=0,
state=0x7fff22a52dc0, num_fields=0x7fff22a52dc6, cont=0x7fff22a52dbb
"\001\372U") at protocol/pool_process_query.c:5117
#5  0x000055fa10734cbf in pool_process_query (frontend=0x55fa123a7768,
backend=0x7f79e74e1168, reset_request=0) at
protocol/pool_process_query.c:247
#6  0x000055fa1072d174 in do_child (fds=0x55fa1235d320) at
protocol/child.c:467
#7  0x000055fa106f2a4c in fork_a_child (fds=0x55fa1235d320, id=14) at
main/pgpool_main.c:863
#8  0x000055fa106f1e30 in PgpoolMain (discard_status=0 '\000',
clear_memcache_oidmaps=0 '\000') at main/pgpool_main.c:561
#9  0x000055fa106ef9e6 in main (argc=2, argv=0x7fff22a60178) at
main/main.c:365

(gdb) info locals
dbname = 0x7f79e74e5fd8 ""
i = 22010
maxrefcnt = 2147483647
query =
"\240)\245\"\377\177\000\000\320&\245\"\377\177\000\000\340\262\364\347y\177\000\000\370)\245\"\377\177\000\000\030\000\000\000\000\000\000\000\030\000\000\0000\000\000\0000)\245\"\377\177\000\000p(\245\"\377\177\000\000X%4\022\372U\000\000\000\000\000\0000\000\000\000h\r\000\000\000\000\000\000\000\000\000\000\377\177\000\000\000\000\000\000y\177\000\000\n\000\000\000\377\177\000\000\000\000\000\000
", '\000' <repeats 11 times>, "p%4\022\372U\000\000\000\000\000\000\001",
'\000' <repeats 11 times>,
"\001\000\000\000\000\000\000\000\377\377\377\377\377\377\377\377\000\000\000\000\000\000\000\000\220#\245\"\377\177\000\000\n\000\000d\000\000\000\000p%4\022\372U\000\000\000\000\000\000\000\000\000\000"...
res = 0x0
index = 0
local_session_id = 1
now = 94532507393728
result = 0x55fa10775e60 <string_register_func>
callback = {previous = 0x55fa108703ad, callback = 0x7f79e7dff238
<__GI__IO_default_xsputn+168>, arg = 0x18}
oldmask = {__val = {0, 0, 18446743111636877312, 0, 94532507411790,
4294967296, 0, 0, 18446744073709551615, 0, 0, 16, 94532507411792, 0,
140161559343840, 140733774636704}}
locked = 0 '\000'
query_cache_not_found = 1
query_cache_data = 0x0
query_cache_len = 3432
session_context = 0x55fa109f0300 <session_context_d>
node_id = 22010

(gdb) p *backend
$3 = {info = 0x7f79df360c08, slots = {0x0, 0x0, 0x7f79e74dda30, 0x0
<repeats 125 times>}}

(gdb) p backend->slots[0]
$4 = (POOL_CONNECTION_POOL_SLOT *) 0x0
(gdb) p backend->slots[1]
$5 = (POOL_CONNECTION_POOL_SLOT *) 0x0
(gdb) p backend->slots[2]
$6 = (POOL_CONNECTION_POOL_SLOT *) 0x7f79e74dda30
(gdb) p *backend->slots[2]
$7 = {sp = 0x7f79e74dd7a0, pid = 1392574464, key = -886960624, con =
0x7f79e74e0548, closetime = 0}

The crash happens at the same time as the other crashes: all 3 nodes are
rebooted simultaneously and when the last node rejoins, the crashes happen.
I've attached the logs and the coredump.

Best regards,
Emond
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