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Re: slapadd hang in bdb_tool_entry_close / ldap_pvt_thread_cond_wait



Bannister, Mark wrote:
Hi,

Can anyone shed light on why my slapadd process on Solaris 11 was hanging
(slapd 2.4.30)?  I was piping ‘gunzip -c’ through to slapadd (from an
overnight cron job).  This usually works fine. I’m guessing perhaps the gunzip
process encountered an error, maybe an EPIPE was sent, but the stack trace
many days later from slapadd doesn’t look right.  Only 2 threads, and both of
them in ldap_pvt_thread_cond_wait(), but no other threads so what are they
waiting for exactly?

You'd need a backtrace with debug symbols to know exactly.

Your lwp #2 is in the thread pool, probably waiting for lwp #1 to finish. Why lwp #1 is still waiting, dunno.

# pstack /var/tmp/cores/core.slapd.0.16189.1463492837

core '/var/tmp/cores/core.slapd.0.16189.1463492837' of 16189:
/usr/sbin/slapadd -q -f /etc/openldap/slapd.conf

------------  lwp# 1 / thread# 1  ---------------

07ff7af9 lwp_park (0, 0, 0)

07ff1193 cond_wait_queue (82ed048, 82ed020, 0, 7ff16b0) + 63

07ff1728 __cond_wait (82ed048, 82ed020, f5a685c8, 7ff1771) + 89

07ff177f cond_wait (82ed048, 82ed020, f5a685f8, 7ff17b7) + 27

07ff17cc pthread_cond_wait (82ed048, 82ed020, f5a68618, 7e56137) + 24

07e5614c ldap_pvt_thread_cond_wait (82ed048, 82ed020, f5a68648, 81b7e29) + 24

081b7e7a bdb_tool_entry_close (8e9d398, ffffffff, f5a68698, 82ecc38) + 62

081a38ec slapadd  (4, f5a68bbc, f5a68bbc, 80dccb1) + cb8

080dcd2c main     (4, f5a68bbc, f5a68bd0, ef60f968) + ac

080dc86d _start   (4, f5a68c8e, f5a68ca0, f5a68ca3, f5a68ca6, 0) + 7d

------------  lwp# 2 / thread# 2  ---------------

07ff7af9 lwp_park (0, 0, 0)

07ff1193 cond_wait_queue (8e6b0e4, 8e6b0cc, 0, 7ff16b0) + 63

07ff1728 __cond_wait (8e6b0e4, 8e6b0cc, d7dffdb8, 7ff1771) + 89

07ff177f cond_wait (8e6b0e4, 8e6b0cc, 8e6b0c8, 7ff17b7) + 27

07ff17cc pthread_cond_wait (8e6b0e4, 8e6b0cc, 0, 7e56137) + 24

07e5614c ldap_pvt_thread_cond_wait (8e6b0e4, 8e6b0cc, d7dfffc8, 7e54bfc) + 24

07e54d66 ldap_int_thread_pool_wrapper (8e6b0c8, 803a000, d7dfffe8, 7ff7769) + 242

07ff77bc _thrp_setup (ee1e0240) + 9d

07ff7aa0 _lwp_start (ee1e0240, 0, 0, 0, 0, 0)

Thanks,

Mark.



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