Server Reboots

     I will be rebooting the host machines (which in turn will reboot all the servers) to load a new kernel that fixes some issue with UDP offloading on the ethernet port that was introduced with the last kernel upgrade.  Outages should be brief (approx 10 minutes each machine).

Apache Web Server Upgrade

     The apache web server has been upgraded to 2.4.28.  This upgrade primarily fixes a problem where by it was possible to obtain random memory data under certain circumstances.  Unfortunately, Apache caching still seems to occasional serve the wrong page.

Maintenance Completed

     Maintenance work for the night is completed.  We’ll will have individual servers go down tomorrow evening and Saturday evening for about 15-30 minutes each in order to back up those servers in preparation for upgrade to Ubuntu 17.10.

     This will affect mx1, mx2, ftp, ubuntu, and several other machines that are new and not yet fully in service.

     I will be rebooting servers in about an hour to upgrade kernels and test a fix to systemd.  If the fix works this will be a short interruption of about the minutes.  If not it may take approximately 45 minutes.

Web Server Caching

     I want to serve as much content out of memory as possible because you can’t get faster than that.  Google’s pagespeed module did not play nice with suexec or phpexec so I had to take that back out.  Memcached also occasionally corrupted pages, so got rid of that.  Now what I’ve done is created an in memory file system and used apache file caching.  Please notify if you see any bad behavior like corrupted css files.

Web Server

     Sorry for the somewhat flakey operation of the web server today.

     I tried to implement two different server optimizations, Apache’s caching in concert with memcached.  This mostly worked but occasionally corrupted pages so I had to back it out.

     Then I tried to run mod_pagespeed, a Google Apache optimization module, but it did not peacefully co-exist with provisions we use to run dynamic code under the user id of the user that owns that code resulting in all sorts of random permission errors.  So ultimately I had to back that one out as well.


     The programming language Julia is now available on all of our shell servers.  This language can be interpreted (with just in time compiling), or compiled to object.  It has a syntax in many ways similar to C++ but has a much more extensive set of math operations.  It can handle complex and imaginary numbers for example.  It also has nicer string operations than C or C++.  It has built in regex capability.  All in all it’s a very impressive language and worth checking out.

     It is also on our web server so you can use it for CGI’s if you like.