Speed issues etc

[James]

The speed issues seem to have cleared up (for now at least), however I wouldn't be surprised if we have the problem again soon. Just to let you know, we are looking in to replacing this server for a fully dedicated one, however the costs are much higher so we will have to factor this into the costings.

I posted on the Facebook group just now an explanation of what I think is causing the slowdown, and thought I'd put it on here too now to hopefully give you guys some insight into what's going on.

I fully understand that (especially for paying members) the downtime we've been having is both annoying and unacceptable and please be assured we are doing everything we can to get this resolved as quickly as possible.

The current server we have has dedicated hardware but has its storage (hard drives) based on an external SAN somewhere in the ISPs datacentre.

What this essentially means is we're restricted by network speeds as to how fast we can transfer data. On a normal website that wouldn't matter, but with a forum such as ours with a 1.2GB MySQL database and over 5GB of attachment files, it can have a significant impact on the server.

This situation isn't helped by the fact our number of requests per second seems to have tripled in late Jan and Feb:

To compare it with other servers I run for clients etc, here are the results of the same hard drive benchmark program run on different servers. First off, the MSC server:

 Timing cached reads:   1304 MB in  2.00 seconds = 652.02 MB/sec
 Timing buffered disk reads:   12 MB in  3.27 seconds =   3.67 MB/sec

and now various other servers I manage:

 Timing cached reads:   500 MB in  2.01 seconds = 249.14 MB/sec
 Timing buffered disk reads:   80 MB in  3.06 seconds =  26.11 MB/sec

 Timing cached reads:   3392 MB in  2.00 seconds = 1696.26 MB/sec
 Timing buffered disk reads:  104 MB in  3.29 seconds =  31.63 MB/sec

 Timing cached reads:   4856 MB in  2.00 seconds = 2428.60 MB/sec
 Timing buffered disk reads:  328 MB in  3.06 seconds = 107.36 MB/sec

I think the value that has the most impact is the buffered disk reads, which as you can see are EXTREMELY low on the MSC's server, hence all the problems we seem to be having. The last exmaple is on a server that's actually still LESS powerful than the one we are looking for as a replacement, so if we do end up going for it, we should notice a drastic improvement!

Sorry for the length, and hopefully some of it made sense!

James.

 

[timminski]

The speed issues seem to have cleared up (for now at least), however I wouldn't be surprised if we have the problem again soon. Just to let you know, we are looking in to replacing this server for a fully dedicated one, however the costs are much higher so we will have to factor this into the costings.

I posted on the Facebook group just now an explanation of what I think is causing the slowdown, and thought I'd put it on here too now to hopefully give you guys some insight into what's going on.

I fully understand that (especially for paying members) the downtime we've been having is both annoying and unacceptable and please be assured we are doing everything we can to get this resolved as quickly as possible.

The current server we have has dedicated hardware but has its storage (hard drives) based on an external SAN somewhere in the ISPs datacentre.

What this essentially means is we're restricted by network speeds as to how fast we can transfer data. On a normal website that wouldn't matter, but with a forum such as ours with a 1.2GB MySQL database and over 5GB of attachment files, it can have a significant impact on the server.

This situation isn't helped by the fact our number of requests per second seems to have tripled in late Jan and Feb:

To compare it with other servers I run for clients etc, here are the results of the same hard drive benchmark program run on different servers. First off, the MSC server:

 Timing cached reads:   1304 MB in  2.00 seconds = 652.02 MB/sec
 Timing buffered disk reads:   12 MB in  3.27 seconds =   3.67 MB/sec

and now various other servers I manage:

 Timing cached reads:   500 MB in  2.01 seconds = 249.14 MB/sec
 Timing buffered disk reads:   80 MB in  3.06 seconds =  26.11 MB/sec

 Timing cached reads:   3392 MB in  2.00 seconds = 1696.26 MB/sec
 Timing buffered disk reads:  104 MB in  3.29 seconds =  31.63 MB/sec

 Timing cached reads:   4856 MB in  2.00 seconds = 2428.60 MB/sec
 Timing buffered disk reads:  328 MB in  3.06 seconds = 107.36 MB/sec

I think the value that has the most impact is the buffered disk reads, which as you can see are EXTREMELY low on the MSC's server, hence all the problems we seem to be having. The last exmaple is on a server that's actually still LESS powerful than the one we are looking for as a replacement, so if we do end up going for it, we should notice a drastic improvement!

Sorry for the length, and hopefully some of it made sense!

James.

Hey, you sure know your stuff.

I've sent you a PM.