On 15/11/2010 14:46, Patrick Boutilier wrote: > On 11/15/2010 10:36 AM, David Mayo wrote: >> >> Having looked at the source code, we can see that ctl_cyrusdb does not >> touch deliver.db and it is not possible to force checkpoints on or off >> within lmtpd. Ideally we want to schedule the checkpointing to a "less >> sociable" time. >> >> On our setup, the checkpoint runs every couple of days and usually takes >> 4-6 minutes[1]. We run cyr_expire every night to remove entries older >> than 3 days from the duplicate deliveries database but this is the only >> maintenance we can schedule on this database. > > No solution, but I wonder why your checkpoint takes so long? With > similar DB size it take only seconds here. > > Nov 8 21:18:04 student2 lmtpunix[6541]: skiplist: checkpointed > /var/imap/deliver.db (650493 records, 67180160 bytes) in 5 seconds > > Nov 12 23:14:06 student2 lmtpunix[26425]: skiplist: checkpointed > /var/imap/deliver.db (768262 records, 80010936 bytes) in 11 seconds Looking back further through our logs, I found a checkpoint that was run overnight which completes somewhat faster, but nowhere near your times! Our IMAP back-end is running on a 4x Quad-Core AMD Opteron 2.3 GHz processor with 16 GB RAM: Oct 14 00:17:47 imap.bath.ac.uk lmtp[29924]: [ID 301543 mail.info] skiplist: checkpointed /opt/etc/imapd/deliver.db (715978 records, 68761076 bytes) in 76 seconds This presumably doesn't cause anyone much trouble overnight, but it's a bit more noticeable during the day. Regards, Dave. David Mayo Networks/Systems Administrator University of Bath Computing Services, UK >> Do other people suffer from this? Is there a patch that anyone has >> written and/or will be submitting upstream any time soon? >> >> We are running Cyrus 2.3.13 across a front end, a back end and a >> replication host for around 25,000 users. >> >> Regards, >> >> >> Dave. >> >> David Mayo >> Networks/Systems Administrator >> University of Bath Computing Services, UK >> >> [1] >> Nov 4 15:32:33 imap.bath.ac.uk lmtp[29595]: [ID 301543 mail.info] >> skiplist: checkpointed /opt/etc/imapd/deliver.db (787618 records, >> 74775536 bytes) in 386 seconds >> Nov 9 14:26:06 imap.bath.ac.uk lmtp[1676]: [ID 301543 mail.info] >> skiplist: checkpointed /opt/etc/imapd/deliver.db (386167 records, >> 36638408 bytes) in 232 seconds >> Nov 11 12:45:35 imap.bath.ac.uk lmtp[2497]: [ID 301543 mail.info] >> skiplist: checkpointed /opt/etc/imapd/deliver.db (657254 records, >> 62540568 bytes) in 396 seconds ---- Cyrus Home Page: http://www.cyrusimap.org/ List Archives/Info: http://lists.andrew.cmu.edu/pipermail/info-cyrus/
