Performance bottlenecks

[Lob]

your bottlenecks, Mark - are they really disk I/O-related or is something funky happening on the NIC or is it on Apache 2.0.52 or PHP 4.9?

[mark]

Yes the announcements forum is supposed to be locked - since that's where I make announcements to you guys, not the other way around

So basically this is the correct area to ask such questions. Here's s snippet from the command "vmstat 5"

procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 5 366200 8824 3840 23020 423 271 1238 758 1243 942 36 39 0 25 1 9 366720 1308 3768 22428 602 307 1323 810 1230 674 19 24 0 57 0 7 367352 6084 4052 22120 1028 196 1412 580 1204 283 9 21 0 70 0 5 367852 1600 3208 18312 715 230 1091 589 1203 280 19 24 0 57 1 4 368268 1796 2236 17344 675 380 1237 572 1195 421 25 30 0 45 4 2 369116 4356 2816 21448 630 555 1409 991 1231 450 22 31 0 47 1 3 373372 956 2744 22372 505 2190 1021 2446 1289 357 30 29 0 41 1 5 376612 9296 3232 25836 711 974 1442 1331 1204 272 18 28 0 54 1 4 379508 1432 3484 25960 1234 719 1606 1371 1217 380 14 20 0 66 2 3 380952 1028 3636 23104 1039 446 1351 630 1169 477 19 36 0 45 0 2 381724 7136 4368 23668 1055 330 1582 505 1212 291 2 15 0 83 0 3 380952 4684 5140 28188 511 0 2110 374 1194 367 5 19 0 76 0 1 380952 3000 5796 30688 454 0 1057 198 1126 311 6 30 20 44

If you know the output of this command (which I suspect you do) you'll agree there is a bit of a disc bottleneck problem.

This was just a random snippet I grabbed off my monitor, it has looked much worse!

I'm currently weighing up buying a fancy new server, verses outsourcing to a virtual server with a big ISP... But don't worry - I'm not ignoring the problem!!

Mark

[mark]

Actually, maybe I should clarify that a bit further. The present server has 256MB of RAM and is struggling when it comes to swapping. The additional swapping is helping to create a disk bottleneck. I'm about to order a fancy new server with 2GB ram dual core processor, etc, but it will take about 2 weeks. In the meantime I'm kind of loathed to go out and buy memory for a machine I'm about to retire! The old machine is DDR, the new one is DDR2, so the new memory I'm buying won't work in the old machine...

Mark

[mark]

Ok, I felt a bit bad, so I went out and bought some new memory anyway for the old server. It won't be of any use when the new server arrives, but at least things should run a bit faster until that happens. Hopefully now that there is more memory there will be less thrashing of the disc due to swapping, increased caching etc. Should take the load of the disc in the short term. So far everything seems to be running very quickly, though weekends aren't such a busy time. Let's see next week how the speed is!

Regards,
Mark

[Lob]

I used to have 256Mb on my server and it was tragic; 768Mb is *just* enough and I can't be bothered to get more Old Proliant DL320R 1U server with dual SCSI disks......which also help with decent-rate I/O. And my comment here was in reply to your complaints of no feedback in your locked Announcements forum

[mark]

Well the server has been at 512MB now and it seems to be behaving.. How much mem you need depends on what's going on I suppose, or if you run windows (which I don't!). Yes, your comment about the locked thread is a fair one - I've changed it now so that only I can make announcements, but announcements can be replied to. Kinda sensible....

Mark

[Lob]

swapping is a nightmare huh?
SCSI disks also give better I/O - I have an old P2/400 system with SCSI disks which assist it in outperforming a Coppermine CPU machine running similar tasks.....

[mark]

I'm going to go with S-ATA 10,000RPM - The WD Raptor. Not quite as fast as high end SCSI, but at 4.5ms it's pretty decent! Anyway, since the extra RAM seems to have taken the heat off the disc, I guess this isn't such a big deal anymore... In other news, I cancelled the order with digitec - majorly slack pre-sales service. Now I just have to look forward to being messed around by the next supplier

[Lob]

Digitec are usually ok; I buy most of my stuff from them.....

So what did you actually pre-order with them? Who are you going to use next?

[mark]

	Quote:	Lob Rockster
	Digitec are usually ok; I buy most of my stuff from them..... So what did you actually pre-order with them? Who are you going to use next?

I ordered a 2U high server case and all the bits to go in it. Turns out that it wasn't that flexible with respect to the types of MBs and CPUs I could put into it, and the costs started to spiral. Of course, I only found this out 2 weeks later when they answered my emails about it - multiple phone requests were rudely deflected. The next crowd are http://www.shop-24.cc

Not so sure about them, but we'll have to see. This time I went for a 1U high barebone setup with less space for disks. But the RAM isn't in stock - I added a note to the order saying that I wished to be informed if there would be a delay, but 3 working days on and no communication from them. These days I'm doing everything by nachnahme - I'm sicking of paying in advance for stuff they don't turn out to have! At least this crowd don't make you pay 2 francs per minute to call them on a 900 number like some others!!

[dogobert2]

Did you Solve this problem, have some dual Processor Servers lying around. And a 1.5Tb, 8Gb Server with Redundant gigabit links links waiting for traffic.... If you like... Greets Daniel