Re: assessing parallel-safety

On 20 March 2015 at 15:25, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Fri, Mar 20, 2015 at 11:08 AM, Thom Brown <thom(at)linux(dot)com> wrote:
>> On 20 March 2015 at 15:02, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>>> On Fri, Mar 20, 2015 at 10:24 AM, Thom Brown <thom(at)linux(dot)com> wrote:
>>>> 2015-03-20 14:19:31 GMT [4273]: [78-1] user=,db=,client= DEBUG:
>>>> server process (PID 4285) was terminated by signal 11: Segmentation
>>>> fault
>>>
>>> Any chance you can get us a stack backtrace of this crash?
>>
>> (gdb) cont
>> Continuing.
>>
>> Program received signal SIGSEGV, Segmentation fault.
>> 0x0000000000770843 in pfree ()
>> (gdb) bt
>> #0 0x0000000000770843 in pfree ()
>> #1 0x00000000005a382f in ExecEndFunnel ()
>> #2 0x000000000059fe75 in ExecEndAppend ()
>> #3 0x00000000005920bd in standard_ExecutorEnd ()
>> #4 0x000000000055004b in ExplainOnePlan ()
>> #5 0x000000000055025d in ExplainOneQuery ()
>> #6 0x000000000055064d in ExplainQuery ()
>> #7 0x0000000000680db1 in standard_ProcessUtility ()
>> #8 0x000000000067e1c1 in PortalRunUtility ()
>> #9 0x000000000067ef1d in FillPortalStore ()
>> #10 0x000000000067f8eb in PortalRun ()
>> #11 0x000000000067d628 in PostgresMain ()
>> #12 0x0000000000462c5e in ServerLoop ()
>> #13 0x000000000062e363 in PostmasterMain ()
>> #14 0x00000000004636ad in main ()
>
> OK, thanks. That looks like it's probably the fault of parallel seq
> scan patch rather than this one. It would help if you could build
> with debug symbols so that we can see line numbers and arguments.

Sure.

Program received signal SIGABRT, Aborted.
0x00007f5a49fce1d5 in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0 0x00007f5a49fce1d5 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007f5a49fd1388 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2 0x00000000007a053a in ExceptionalCondition
(conditionName=conditionName(at)entry=0x813a4b "!(IsInParallelMode())",
errorType=errorType(at)entry=0x7da1d6 "FailedAssertion",
fileName=fileName(at)entry=0x81397d "parallel.c", lineNumber=lineNumber(at)entry=123)
at assert.c:54
#3 0x00000000004cd5ba in CreateParallelContext
(entrypoint=entrypoint(at)entry=0x659d2c
<ParallelQueryMain>, nworkers=nworkers(at)entry=8) at parallel.c:123
#4 0x000000000065a1c0 in InitializeParallelWorkers (plan=0x281e6a0,
estate=estate(at)entry=0x28b99a8, rel=rel(at)entry=0x7f594eab2370,
inst_options_space=inst_options_space(at)entry=0x28bbfa8,
buffer_usage_space=buffer_usage_space(at)entry=0x28bbfb0,
responseqp=responseqp(at)entry=0x28bbf98, pcxtp=pcxtp(at)entry=0x28bbf90,
nWorkers=8) at backendworker.c:279
#5 0x00000000005d0e75 in InitFunnel (node=node(at)entry=0x28bbf00,
estate=estate(at)entry=0x28b99a8, eflags=eflags(at)entry=17) at nodeFunnel.c:61
#6 0x00000000005d1026 in ExecInitFunnel (node=0x281e738, estate=0x28b99a8,
eflags=17) at nodeFunnel.c:121
#7 0x00000000005c0f95 in ExecInitNode (node=0x281e738,
estate=estate(at)entry=0x28b99a8,
eflags=eflags(at)entry=17) at execProcnode.c:201
#8 0x00000000005cd316 in ExecInitAppend (node=<optimized out>,
estate=0x28b99a8, eflags=17) at nodeAppend.c:168
#9 0x00000000005c0f25 in ExecInitNode (node=0x288b990,
estate=estate(at)entry=0x28b99a8,
eflags=eflags(at)entry=17) at execProcnode.c:163
#10 0x00000000005ce849 in ExecInitAgg (node=0x288ba28, estate=0x28b99a8,
eflags=17) at nodeAgg.c:1580
#11 0x00000000005c10bf in ExecInitNode (node=node(at)entry=0x288ba28,
estate=estate(at)entry=0x28b99a8, eflags=eflags(at)entry=17) at execProcnode.c:302
#12 0x00000000005bfb35 in InitPlan (queryDesc=queryDesc(at)entry=0x28b5868,
eflags=eflags(at)entry=17) at execMain.c:939
#13 0x00000000005bfd49 in standard_ExecutorStart (queryDesc=0x28b5868,
eflags=17) at execMain.c:234
#14 0x00000000005bfd95 in ExecutorStart (queryDesc=queryDesc(at)entry=0x28b5868,
eflags=eflags(at)entry=1) at execMain.c:134
#15 0x0000000000573f21 in ExplainOnePlan
(plannedstmt=plannedstmt(at)entry=0x28b7878,
into=into(at)entry=0x0, es=es(at)entry=0x24cde68,
queryString=queryString(at)entry=0x248a398
"EXPLAIN SELECT DISTINCT bid FROM pgbench_accounts;", params=params(at)entry=0x0,
planduration=planduration(at)entry=0x7fffb64f4bf0) at explain.c:478
#16 0x0000000000574160 in ExplainOneQuery (query=<optimized out>,
into=into(at)entry=0x0, es=es(at)entry=0x24cde68,
queryString=queryString(at)entry=0x248a398
"EXPLAIN SELECT DISTINCT bid FROM pgbench_accounts;", params=params(at)entry=0x0)
at explain.c:346
#17 0x000000000057478a in ExplainQuery (stmt=stmt(at)entry=0x248b1b0,
queryString=queryString(at)entry=0x248a398 "EXPLAIN SELECT DISTINCT bid FROM
pgbench_accounts;", params=params(at)entry=0x0, dest=dest(at)entry=0x24cddd0) at
explain.c:234
#18 0x00000000006c6419 in standard_ProcessUtility (parsetree=0x248b1b0,
queryString=0x248a398 "EXPLAIN SELECT DISTINCT bid FROM pgbench_accounts;",
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, dest=0x24cddd0,
completionTag=0x7fffb64f4d90 "") at utility.c:657
#19 0x00000000006c6808 in ProcessUtility (parsetree=parsetree(at)entry=0x248b1b0,
queryString=<optimized out>, context=context(at)entry=PROCESS_UTILITY_TOPLEVEL,
params=<optimized out>, dest=dest(at)entry=0x24cddd0,
completionTag=completionTag(at)entry=0x7fffb64f4d90 "") at utility.c:333
#20 0x00000000006c3272 in PortalRunUtility (portal=portal(at)entry=0x24f2e28,
utilityStmt=0x248b1b0, isTopLevel=<optimized out>, dest=dest(at)entry=0x24cddd0,
completionTag=completionTag(at)entry=0x7fffb64f4d90 "") at pquery.c:1188
#21 0x00000000006c4039 in FillPortalStore (portal=portal(at)entry=0x24f2e28,
isTopLevel=isTopLevel(at)entry=1 '\001') at pquery.c:1062
#22 0x00000000006c4a12 in PortalRun (portal=portal(at)entry=0x24f2e28,
count=count(at)entry=9223372036854775807, isTopLevel=isTopLevel(at)entry=1
'\001', dest=dest(at)entry=0x248b5e8, altdest=altdest(at)entry=0x248b5e8,
completionTag=completionTag(at)entry=0x7fffb64f4fa0 "") at pquery.c:786
#23 0x00000000006c12c3 in exec_simple_query
(query_string=query_string(at)entry=0x248a398
"EXPLAIN SELECT DISTINCT bid FROM pgbench_accounts;") at postgres.c:1107
#24 0x00000000006c2de4 in PostgresMain (argc=<optimized out>,
argv=argv(at)entry=0x2421c28, dbname=0x2421a90 "pgbench", username=<optimized
out>) at postgres.c:4118
#25 0x0000000000665c55 in BackendRun (port=port(at)entry=0x2447540) at
postmaster.c:4148
#26 0x00000000006675a8 in BackendStartup (port=port(at)entry=0x2447540) at
postmaster.c:3833
#27 0x000000000066784b in ServerLoop () at postmaster.c:1601
#28 0x000000000066898d in PostmasterMain (argc=argc(at)entry=1,
argv=argv(at)entry=0x2420c90)
at postmaster.c:1248
#29 0x00000000005f5a25 in main (argc=1, argv=0x2420c90) at main.c:221

--
Thom