[Linux-cluster] GFS or Web Server Performance issues?

[Wendy Cheng]

isplist at logicore.net wrote:

>Here is ab sending a test to an LVS server in front of a 3 node web server. 
>The average loads on each server was around 8.00 to 10.00. These aren't very 
>good numbers and I'm wondering where to start looking.
>  
>

Using a load balancer in front of GFS nodes is tricky. Make sure to set 
your scheduling rule (or whatever it is called in LVS) in such a way 
that it would not generate un-necessary lock traffic. For example, you 
don't want the same write lock to get rotated between three nodes. Be 
aware that moving a write lock between nodes requires many steps that 
include a disk flush.

-- Wendy

>These are pretty much default apache RPM versions out of the box.
>
># ab -kc 50 -t 30 http://192.168.1.150/
>This is ApacheBench, Version 2.0.41-dev <$Revision: 1.141 $> apache-2.0
>Copyright (c) 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
>Copyright (c) 1998-2002 The Apache Software Foundation, http://www.apache.org/
>
>Benchmarking 192.168.1.150 (be patient)
>Finished 130 requests
>
>
>Server Software:        Apache
>Server Hostname:        192.168.1.150
>Server Port:            80
>
>Document Path:          /
>Document Length:        8997 bytes
>
>Concurrency Level:      50
>Time taken for tests:   30.234185 seconds
>Complete requests:      130
>Failed requests:        0
>Write errors:           0
>Keep-Alive requests:    0
>Total transferred:      1371090 bytes
>HTML transferred:       1299586 bytes
>Requests per second:    4.30 [#/sec] (mean)
>Time per request:       11628.532 [ms] (mean)
>Time per request:       232.571 [ms] (mean, across all concurrent requests)
>Transfer rate:          44.25 [Kbytes/sec] received
>
>Connection Times (ms)
>              min  mean[+/-sd] median   max
>Connect:        0    1   1.4      2       4
>Processing:   409 6228 4357.5   5227   16317
>Waiting:      369 6146 4370.8   5199   16261
>Total:        409 6230 4358.1   5230   16321
>
>Percentage of the requests served within a certain time (ms)
>  50%   5230
>  66%   8331
>  75%   9310
>  80%  10386
>  90%  12820
>  95%  14502
>  98%  15399
>  99%  15746
> 100%  16321 (longest request)
>
>
>
>--
>Linux-cluster mailing list
>Linux-cluster at redhat.com
>https://www.redhat.com/mailman/listinfo/linux-cluster
>  
>