Thread

1. waiting for lock?

   Lennert Buytenhek <buytenh@gnu.org> — 2000-11-02T20:20:00Z

   Hi,
   
   this evening I found a whole bunch of cron jobs hanging on a VACUUM of a
   database. I killed them off and retried manually:
   
   ulsec=> vacuum;
   NOTICE:  Skipping "pg_type" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_attribute" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_proc" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_class" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_indexes" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_group" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_database" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_attrdef" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_relcheck" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_trigger" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_inherits" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_index" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_statistic" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_operator" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_opclass" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_am" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_amop" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_amproc" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_language" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_aggregate" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_ipl" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_inheritproc" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_rewrite" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_listener" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_description" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_shadow" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_user" --- only table owner can VACUUM it
   NOTICE:  Skipping "pg_rules" --- only table owner can VACUUM it
   
   
   
   And there it hangs.
   
   strace reveals that the corresponding postgres process on the server hangs
   on:
   
   semop(10241, 0xbfffe924, 1
   
   
   If you send psql a SIGINT, it returns with:
   
   NOTICE:  Skipping "pg_rules" --- only table owner can VACUUM it
   Cancel request sent
   ERROR:  Query cancel requested while waiting lock
   ulsec=>
   
   
   When this happened, no other clients were accessing the database.
   Restarting the server (postgresql 7.0.2) cured all. Anyone knows what's
   going on there?
   
   
   
   /Lennert
   
   
   
   

2. Re: waiting for lock?

   Tom Lane <tgl@sss.pgh.pa.us> — 2000-11-02T21:11:37Z

   Lennert Buytenhek <buytenh@gnu.org> writes:
   > If you send psql a SIGINT, it returns with:
   > NOTICE:  Skipping "pg_rules" --- only table owner can VACUUM it
   > Cancel request sent
   > ERROR:  Query cancel requested while waiting lock
   > ulsec=>
   
   > Restarting the server (postgresql 7.0.2) cured all.
   
   Hmph.  Something quit and left a lock set on some table (whatever
   VACUUM would've come to after pg_rules), it looks like.  Could be
   an artifact of the known bug in 7.0.* that shared memory state isn't
   properly cleaned up when a client disconnects in the middle of a
   BEGIN block.  That's fixed for 7.0.3, if we ever quit arguing and
   push it out the door ;-)
   
   			regards, tom lane