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> -----Original Message----- > From: Adam Nellemann [mailto:adam at nellemann dot nu] > Sent: Thursday, 8 April 2004 11:45 AM > To: rick at scorpion dot co dot th; m0n0wall at lists dot m0n0 dot ch > Subject: Re: [m0n0wall] about the load averages: 2.11, 0.07, 0.05 > > > Hi Rick, > > Rick Ruggiero wrote: > > It means, the following: > > > > load averages: 2.11% (Avg. process queue last minute), 0.07% (Avg. > > process queue last 5 minutes), 0.05% (avg process queue last 15 > > minutes). > > > > I don't have the m0n0wall running properly yet, but generally > > uptime is the same on all UNIX platforms. > > I think it was previously established that the three numbers > corrospond to the average percentage for the last 1, 5 and 15 > minutes respectivly, but I do find it somewhat illuminating > that these numbers are related to the process queue. > > However, there still remain some things to be explained: > > - How to understand the term "process queue" precisely (this > might be simple stuff for a *NIX guru, whereas I, not knowing > much about *NIX, can only guess at the exact meaning). The load average numbers give the number of jobs in the run queue (actively being processed) > > - What the number (percentage) indicates, the average > wait-time in the queue, the average queue length or something > else entirely? No, unfortunately you cannot use this number to predict CPU,IO latency, etc. Each process has a discrete impact many other system metrics which does affect overall system performance (and the values being displayed). > > - What is this percentage relative to? (That is, what is > 100.00%, and can it become higher than that?) Yes, it is relative to 100%; and no, it does not display greater than 100% (well from my experience at least). > > - And finally, how this "average process queue" percentage > relates to such things as CPU load, latency and general > system performance? This is all dependant on the processes currently in the run queue. Some processes may be blocked on I/O which often has a severe impact on this value. However, generally speaking (and I am opening myself to abuse here) any time your process average for 1-5 minutes is over 6, you will find that process spawning is dramatically affected. I do not have a magic answer on this, or a formula where you can start doing transaction prediction modelling. > > Unless one has some idea of the answers to the above > questions, the numbers have little meaning and will be of > even less use. If, on the other hand, you know how these > numbers are arrived at, you could use them, among many > things, to see if it is time to start looking for faster > hardware. Also, we might perhaps finally get some > authoritative statements about how much bandwidth m0n0wall > can handle on particular platforms (such as the Soekris boards). > I think if you look at my statement above, you may have a glimpse as to my approach to this question; If my CPU is regularly demonstrating a process queue of 6 or greater, I would look seriously into a processor upgrade, however if my load averages were "load averages: 2.11, 0.07, 0.05", I'd be very happy. I hope I was a little clearer with this response. Cheers, Rick |