Postgres Pro
Downloads
Home   >   mailing lists

Re: psql tests hangs - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: psql tests hangs
Date
Msg-id CAFj8pRBhfoSkMd2hXJSiHmRXB-_6ezrwYtLaWSyr3s=nsPnZUA@mail.gmail.com
Whole thread Raw
In response to Re: psql tests hangs  (Kirk Wolak <wolakk@gmail.com>)
Responses Re: psql tests hangs
Re: psql tests hangs
List pgsql-hackers
Tree view


pá 12. 5. 2023 v 8:20 odesílatel Kirk Wolak <wolakk@gmail.com> napsal:
On Fri, May 12, 2023 at 1:46 AM Pavel Stehule <pavel.stehule@gmail.com> wrote:
pá 12. 5. 2023 v 6:50 odesílatel Kirk Wolak <wolakk@gmail.com> napsal:
On Fri, May 12, 2023 at 12:14 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Kirk Wolak <wolakk@gmail.com> writes:
> Did you try the print statement that Andrey asked Pavel to try?
...

The strange thing is hanging. Broken tests depending on locale are usual. But I didn't remember hanging.

Regards

Pavel

So, if you do psql -c "..."
with both of those \watch  instructions, do either one hang? (I am now guessing "no")

I know that perl is using a special library to "remote control psql" (like a pseudo terminal, I guess).
[I had to abort some of the perl testing in Windows because that perl library didn't work with my psql in Windows]

Next, can you detect which process is hanging? (is it perl, the library, psql, ?).

It hangs in perl

but now I found there is dependency on PSQL_PAGER setting

it started pager in background, I had lot of zombie pspg processes

Unfortunately, when I unset this variable, the test hangs still

here is backtrace

Missing separate debuginfos, use: dnf debuginfo-install perl-interpreter-5.36.1-496.fc38.x86_64
(gdb) bt
#0  0x00007fbbc1129ade in select () from /lib64/libc.so.6
#1  0x00007fbbc137363b in Perl_pp_sselect () from /lib64/libperl.so.5.36
#2  0x00007fbbc1317958 in Perl_runops_standard () from /lib64/libperl.so.5.36
#3  0x00007fbbc128259d in perl_run () from /lib64/libperl.so.5.36
#4  0x000056392bd9034a in main ()

It is waiting on reading from pipe probably

psql is living too, and it is waiting too

Using host libthread_db library "/lib64/libthread_db.so.1".
0x00007f071740bc37 in wait4 () from /lib64/libc.so.6
Missing separate debuginfos, use: dnf debuginfo-install glibc-2.37-4.fc38.x86_64 ncurses-libs-6.4-3.20230114.fc38.x86_64 readline-8.2-3.fc38.x86_64
(gdb) bt
#0  0x00007f071740bc37 in wait4 () from /lib64/libc.so.6
#1  0x00007f07173a9a10 in _IO_proc_close@@GLIBC_2.2.5 () from /lib64/libc.so.6
#2  0x00007f07173b51e9 in __GI__IO_file_close_it () from /lib64/libc.so.6
#3  0x00007f07173a79fb in fclose@@GLIBC_2.2.5 () from /lib64/libc.so.6
#4  0x0000000000406be4 in do_watch (query_buf=query_buf@entry=0x5ae540, sleep=sleep@entry=0.01, iter=0, iter@entry=3) at command.c:5348
#5  0x00000000004087a5 in exec_command_watch (scan_state=scan_state@entry=0x5ae490, active_branch=active_branch@entry=true, query_buf=query_buf@entry=0x5ae540, previous_buf=previous_buf@entry=0x5ae560) at command.c:2875
#6  0x000000000040d4ba in exec_command (previous_buf=0x5ae560, query_buf=0x5ae540, cstack=0x5ae520, scan_state=0x5ae490, cmd=0x5ae9a0 "watch") at command.c:413
#7  HandleSlashCmds (scan_state=scan_state@entry=0x5ae490, cstack=cstack@entry=0x5ae520, query_buf=0x5ae540, previous_buf=0x5ae560) at command.c:230

I am not sure, it is still doesn't work but probably there are some dependencies on my setting

PSQL_PAGER and PSQL_WATCH_PAGER

so this tests fails due my setting

[pavel@localhost postgresql.master]$ set |grep PSQL
PSQL_PAGER='pspg -X'
PSQL_WATCH_PAGER='pspg -X --stream'

Regards

Pavel








 

I would be curious now about the details of your perl install, and your perl libraries...


 

pgsql-hackers by date:

Previous
From: Richard Guo
Date:
Subject: An inefficient query caused by unnecessary PlaceHolderVar
Next
From: Kirk Wolak
Date:
Subject: Re: psql tests hangs