DTrace probes for Cyrus

[Dale Ghent]

I just spent about an hour implementing some basic dtrace SDT probes  
in imapd. Here's a simple example that ranks SELECT'ed folders... a  
decent way to see which folder is most popular on your server over the  
time you allow the dtrace script to collect data:

---------
[root at mercury]/>dtrace -n 'cyrusimap*:::folder-select  
{@counts[copyinstr(arg0),copyinstr(arg1)] = count();}'
dtrace: description 'cyrusimap*:::folder-select ' matched 4 probes
^C

   daleg    ASTRO/LOSMANDY-USERS        1
   daleg    GEEKS                       1
   daleg    GOA                         1
   daleg    OPENSOLARIS/ZONES-DISCUSS   1
   daleg    ASTRO/STARRYNIGHT           2
   daleg    OPENSOLARIS/ZFS-DISCUSS     2
   daleg    ASTRO/LOSMANDY-USERS        2
   daleg    INBOX                       3
----------

So like I said... basic. On my little personal server, things aren't  
so busy as you can see (me opening my inbox happens the most), but you  
get the point ;)

But probes could be put around various database opens (mailbox db,  
quota db) in order to derive how long it took to open them, as well as  
other imap commands and whatnot. Anyone have any ideas on what they'd  
like to monitor with dtrace? I'll see about implementing what I can.

/dale

--
Dale Ghent
Specialist, Storage and UNIX Systems
UMBC - Office of Information Technology
ECS 201 - x51705