I work for an ISP, and we have several thousand email accounts. My currently POP server is running Solaris 2.5.1 and Qpopper 3.1.2. Other than the fact that the box is getting older, and drive space is becoming limited, the box is running fine.
I'm attempting to upgrade my POP server to a new box (bigger) running Solaris 8. I've configured the box, and thought everything was working great. I put the new box in service yesterday morning, and at first everything was humming along great -- this was in the early morning hours, when utilization was low. As it got closer to peak time (8am) things started to worsen and worsen quickly. The POP service took longer and longer to respond. Load average on the box wasn't high, CPU utilization wasn't high either. However, doing a "df -k" command I noticed that my swap space was shrinking dramatically. I have 1GB of swap space setup (I also have 1GB of RAM), and I was down to less have 400MB of swap space. I then discovered that I had over 1500 active popper sessions running on the box at same time "ps -ef|grep popper|wc -l" My current POP server is lucky if it ever sees 100 concurrent sessions... big difference. This was using QPopper 4.0.3. I also noticed that there were several popper sessions that were currently running that were actually myself checking mail on the box (7 sessions to be exact), and I had closed my mail program by this time. There were other multiple sessions too from other users. my entry in the inetd.conf file looks like this: pop3 stream tcp nowait.600 root /usr/local/lib/popper popper -R the .600 is there because the default of 40 instances per second just wasn't enough, and 100 didn't seem to help, 150 didn't help... 600 worked, and still is. Thinking perhaps the version of qpopper was the problem, I then installed version 3.1.2 (this is the version I'm currently running). Same problem. I then went to sunfreeware.com to get a pre-compiled version (thinking I was doing something wrong other than "./configure;make" I noticed a note on the site saying there were reports of problems with Solaris 8 and qpopper (didn't specify what problems though). To summarize Solaris 8 and Qpopper (versions 3.0.2, 3.1.2, and 4.0.3) seem to have an issue where the pop sessions take an extremely long time to finish and close. Upping the nowait.[max num] parameter helps because it allows more popper sessions to be created in a 60 second window, but that's not fixing the problem, and ultimately not doing me any good. Searching through the archives of this list group, and doing google searches hasn't netted anything yet. If anyone has any suggestions, please let me know.
