Kevin writes:> Appreciate if you could help with this. I have been trying to address this > "slow search" issue for a while with very limited success(I was trying to > implement FTS also), so I will appreciate if you could support.When I'm stumped, one of the diagnostic tools I use is process tracing. Connect via IMAP, in another window/session process trace the IMAP worker process (Linux: strace -r -otrace.dump {pid})), initiate the search and quit. Then you can look through the trace and see whether it gets hung on a particular operation. Joseph Tam <jtam.home at gmail.com>
Hey Joseph Thanks. Strace seems like a very useful tool Only problem is that I dont think it is maintained on ubuntu. Tried to run:- apt-get install strace but could not download it. Might need to download and build it. Do you know any other way of getting it? Thanks Kevin A. On Thu, Jan 29, 2015 at 3:34 PM, Joseph Tam <jtam.home at gmail.com> wrote:> Kevin writes: > > Appreciate if you could help with this. I have been trying to address this >> "slow search" issue for a while with very limited success(I was trying to >> implement FTS also), so I will appreciate if you could support. >> > > When I'm stumped, one of the diagnostic tools I use is process tracing. > Connect via IMAP, in another window/session process trace the IMAP worker > process (Linux: strace -r -otrace.dump {pid})), initiate the search and > quit. Then you can look through the trace and see whether it gets hung on > a particular operation. > > Joseph Tam <jtam.home at gmail.com> >
On Thu, 2015-01-29 at 15:56 +0800, Kevin Laurie wrote:> Hey Joseph > Thanks. Strace seems like a very useful tool > Only problem is that I dont think it is maintained on ubuntu. > Tried to run:- > apt-get install strace but could not download it. > Might need to download and build it. Do you know any other way of getting > it? > Thanks > Kevin A.try apt-cache search strace On Jessie (I'm not running Ubuntu) I get: devscripts - scripts to make the life of a Debian Package maintainer easier dnstracer - trace DNS queries to the source ioapps - IO profiler and IO traces replayer netsniff-ng - Linux network packet sniffer toolkit python-ptrace - Python bindings for ptrace strace - System call tracer subversion-tools - Assorted tools related to Apache Subversion xtrace - trace communication between X client and server You should be able to find the appropriate package to install to get strace. -Thom
Dear Joseph, Just to clarify, the pid you are referring to is of dovecot? Correct? Thanks Kevin On Thu, Jan 29, 2015 at 3:34 PM, Joseph Tam <jtam.home at gmail.com> wrote:> Kevin writes: > > Appreciate if you could help with this. I have been trying to address this >> "slow search" issue for a while with very limited success(I was trying to >> implement FTS also), so I will appreciate if you could support. >> > > When I'm stumped, one of the diagnostic tools I use is process tracing. > Connect via IMAP, in another window/session process trace the IMAP worker > process (Linux: strace -r -otrace.dump {pid})), initiate the search and > quit. Then you can look through the trace and see whether it gets hung on > a particular operation. > > Joseph Tam <jtam.home at gmail.com> >
On Thu, 29 Jan 2015, Kevin Laurie wrote:> Just to clarify, the pid you are referring to is of dovecot?Yes, the dovecot/imap worker process. If there is no system call that is using up a lot of time, but the cumulative open/read time for going through many files in your Maildir, then you have some sort of filesystem metadata performance problem. Joseph Tam <jtam.home at gmail.com>