On Tue, Jul 02, 2013 at 08:54:06PM -0400, Will Platnick wrote: > I am experiencing some issues with load after upgrading some of my Squeeze boxes to Wheezy. I have 7 app servers, all with identical hardware with identical packages and code. I upgraded one of my boxes to wheezy, along with the custom packages we use for Python, PHP, etc… Same versions of the software, just built on Wheezy instead of Squeeze. My problem is that my Wheezy boxes have a load of over 3 and are not staying up during our peak time, whereas our squeeze boxes have a load of less than 1. > The interesting part, is that despite the high load, my wheezy boxes are actually performing quite well, and are outperforming my squeeze boxes by 2-3 ms. Never the less, the high load is giving us cause for concern and is stopping us from migrating completely, and we're wondering if anybody else is seeing the same thing or can give us some assistance on where to go from here. > I believe I have tracked down the issue with our load to be an interrupt issue. My interrupts on wheezy are way higher. CPU, I/O, Memory and Context Switches are all the same (measured with top, atop, iotop, vmstat). It doesn't appear to be a hardware issue, as I deployed wheezy and our code base to a different and faster motherboard/cpu combo, and the issue remained. > The items that stands out is that my "Rescheduling Interrupts" and "timer" are interrupting like crazy on wheezy compared to squeeze. Here is my output of total interrupts on Squeeze vs Wheezy for two different machines, rebooted and placed into service at the exact same time, with traffic distributed to them via round robin, so it should be fairly equal. > Rescheduling Interrupts: 4109580 on Wheezy vs 67418 on Squeeze. > Timer: 504238 on Wheezy vs 50 on Squeeze. > > Thoughts? Suggestions? This was the first search result for "Rescheduling Interrupts". The advice should apply to Debian equally well. https://help.ubuntu.com/community/ReschedulingInterrupts
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