Re: Slow download bitrate **** SOLUTION FOUND *******

Hello all, After 2-3 months of digging I solved my problem through deduction. Turns out this issue is a MS NT issue, possibly SP6 related. Given: ----------------- slow bursty IIS download, ok at times, extremely slow at other times typically when multiple processes (PHP, ASP, or others are executing) A system with multiple disks & multiple pagefile.sys swap partitions Our NT configuration consisted of 2 SCSI controllers with 2+ disks. Drive C had a small (just big enough for memory) pagefile.sys of 400 MB Drive D had a large pagefile.sys 1000 MB Drive C was primary swap, with D secondary. Problem Deduction: --------------------------- When a NT box performs it's startup sequence a list of processes are executed. Each process initializes it's variables requiring SWAP & MEMORY, and some are put to sleep until they are needed. The INETINFO (IIS) process is one of these. It is initialized very early in this process and appears to bind/use the pagefile.sys defined on drive C:. So, everything still cool..... The "GOTCHA" is that inetinfo appears to not be able to use other swap/partition areas on any drive other than C: No matter how large or amount of free swap space is left. In our case, we watched as the swap space was eaten up to about 35% (as it turned out this is the percentage space defined on drive C) and then the problem would result. Seeing lots-o-swap available caused us to look at other reasons for the bursty behavior. During the way-before-problem time there were articles in NT rags recommending different ways to pre-define large contiguous SWAP areas to avoid fragmentation, and to put a "realy-big" one on another SCSI controller & drive (other than C's) to speed performance. This is the way we have existed for many years. Appears to NOT be good advice for our situation. This is a more global in scope that just our configuration. During our trouble period it became so slow that I rebuilt a NT Server from scratch, ported the code, and had the same problem in the same % memory utilization as the other system. This is a MS issue. My problem was that the PHP CGI installer came out right around the same time SP6a came out. Don't know if this swap/pagefile issue is related to SP6, SP6a, but we did not have the problem back in the SP3-5 days..... Eric L. Edberg Lucent Technologies Network Engineering Manager ele@lucent.com "Eric L.. Edberg" wrote: > Hello all, > > I use NT IIS with SP6a to access an MS Access db using ODBC with > ASP based scripts primarily, and have been writing new PHP4 where appropriate > for the past year. > > I am using PHP404pl1 CGI installer and have experienced a troublesome > performance issues after executing PHP scripts (randomly it seems) > > The problem goes like this: > > * ASP scripts execute ok for long periods of time > > * A PHP script (which are seldom executed) appears to execute ok > > * ASP scripts are then executed, but the download bitrate slows to a crawl, > sometime down to the 500b/s rate. The scripts sometimes don't complete due > to timeout issues. > > * After approximately 5 minutes, all ASP scripts start working within expected and normal > rates (50kb/s) > > There appears to be a contention or resource issue between ASP and PHP4. The problem > was not noticed when I was using PHP3. > > Our developers have monitored NT's memory, CPU, Pagefile utilization which are all clean. > We have looked at MS' IIS site for tuning hints and updated some parameters. > > Has anyone else experienced performance issues with IIS that affects the download performance > of html back to the desktop? > > Any IIS/Access experts willing to comment? > > Any know PHP4 bugs? > > Eric Edberg > Network Engineering Manager > Lucent Technologies > 630-713-5231 > ele@lucent.com > > > -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > -- > PHP Windows Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-windows-unsubscribe@lists.php.net > For additional commands, e-mail: php-windows-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net