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Re: hdb stops checkpointing....

johan.jonemo@hep.lu.se wrote: 

--On Monday, November 13, 2006 12:32 PM +0100 johan.jonemo@hep.lu.se
wrote:

I try to modify a hdb periodically (often). After a while the underlying
database seems to be swamped down.

If I look in the directory log files are piling up. I run db_archive
periodically to clean up the log files and I also run db_deadlock in
parallel.

I do not run db_checkpoint as this as far as I understand is done by the
backend.

Yes, checkpointing is handled by the backend if you have that configured. 

Strangely the problem seems to start after about 2 h if I start from a
clean database. When I try to lower the frequency of the updates it
still
seems to happen after 2 h.

I use openLDAP v2.3.24
with Sleepycat Software: Berkeley DB 4.4.20

If you set the right BDB options in DB_CONFIG, I can't see any reason to
run any of the db_* commands.


Then there must be some serious bug in back-hdb because I haven't seen it
delete a single log-file. Wether the db is responsive or not no
(berkley-db-)log files seems to be erased.

back-bdb/back-hdb never delete log files. Log files are owned by the BDB library and we know nothing about them.

My starting point was not to run any "db_"-commands. But as the directory
seems to be acting up I have to try every possibility.

The db-commands seem to delay the breakdown slightly, but I can't tell
because I'm also testing other alternatives. The latest breakdown took 3
hours. The Breakdown times might of course be random. I haven't had time
to statistically establish that the breakdown times tend to any one value.

here is my DB_CONFIG:
set_cachesize 0 16777216 8
set_lg_regionmax 262144
set_lg_bsize 2097152
set_lg_max 16777216

If you want the BDB library to remove the log files you need to use the DB_LOG_AUTOREMOVE option, as described in the BerkeleyDB documentation.

It should be noted that the directory is at no time expected to take on
very large sizes. Otherwise some memory sizes might have been set slightly
higher.

Johan "the one who'll lose his job if he doesn't get this to work" Jönemo 

...

--
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc
  OpenLDAP Core Team            http://www.openldap.org/project/