| Re: VDS with Debian 5 performs much worse than with Debian 3. [message #38749 is a reply to message #38735] |
Sun, 24 January 2010 09:51   |
tryl
Messages: 4
Registered: January 2010
Location: Denmark
|
Junior Member |
|
|
Hello Maratrus
failcnt are all 0.
Iptables does not seem to have any special setup:
zip:~# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
zip:~# iptables -S
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
The performance issue also exists when I just try to wget a static file (like /) on the server.
I have looked at the configuration files of Apache, MySQL and PHP and with regard to memory (limits, number of processes etc.) there are no differences. However, in top, each apache process uses 20-30 MB on the new server, where they are all on 10 MB on the old server.
The obvious difference between the two are the Debian 3/5 versions and PHP 4/5 versions. Unfortunaly PHP 4 is not supported under Debian 5, so I cannot try that. What I plan to try is to run the service from one server and use the database of the other server - and switch that around.
I run the server at a payed provider (yourshelter.net) so I can easily put another configuration on a server...there is just the catch that I rent a server for a whole month and I on production sites the 2 servers I got. I spend a weekend creating accounts and reinstalling apps on the new server, so I really do not want to trash it.
When the load is not at the worst on the new server, after having waited 3-4 sec for e.g. the static file /index.html to load, then it is lightening fast for subsequent requests. The same is also true with regard to access to webapps that uses the database. It is just like that file or that part of the database file is cached in memory. Letting it sit idle for a while it will be slow one time again.
Running on full load, there does not seem to be such caching.
However, top shows at least 250 MB free memory all the time and that is enough to fit half of my databases in memory - the web apps in total takes about 1 MB.
I've thought if that 250 MB is not enough to cache enough data to keep the system fast. Does the 10-20 MB extra for each apache process really make the difference?
I have the indices on the database required to not do full table scans and a read test during the worst load, yielded 40 MB/s when dd'ing an old 250 MB file into /dev/null.
Setting the maximum number of apache processes to either 5 or 20 does not make a difference.
I'm really stuck here. Some things points to memory issues, but others tell otherwise. The same is true for disk speed.
|
|
|
|
OpenVZ Forum
Members
Search
Help
Register
Login
Home
