Apache slow, other services fast

gcan · 12-26-2010, 10:44 AM

Hello,

After server OS (Debian) reinstallation everything was OK and I opened my website to the visitors. After some time I noticed that Apache periodically becames very slow. I can 10-20 clicks and pages load immediately. Then for some 1-2 minutes I can hardly open some page. Then it works fast again. Sometimes 50% of the images on the page load very fast. Then loading freezes for some time, then continues loading again.

Other users report the same problem.

There are no spammers sending spam from this machine or something like that.

When this problem happends, everything runs fast on the server, except Apache. Server load is only ~0.2 - 0.3.

Apache configuration file has default settings and I was running this website with the same scripts and with th same Apache default settings for a long time. Never had problems.

Hostname lookups are disabled.

Any ideas?

PHP Code:



============================= 
 
apache2.conf 
 
Timeout 300 
KeepAlive On 
MaxKeepAliveRequests 100 
KeepAliveTimeout 15 
 
<IfModule mpm_prefork_module> 
    StartServers          5 
    MinSpareServers       5 
    MaxSpareServers      10 
    MaxClients          150 
    MaxRequestsPerChild   0 
</IfModule> 
 
<IfModule mpm_worker_module> 
    StartServers          2 
    MaxClients          150 
    MinSpareThreads      25 
    MaxSpareThreads      75 
    ThreadsPerChild      25 
    MaxRequestsPerChild   0 
</IfModule> 
 
=================================== 
 
my.cnf 
 
key_buffer              = 16M 
max_allowed_packet      = 16M 
thread_stack            = 128K 
thread_cache_size       = 8 
query_cache_limit       = 1M 
query_cache_size        = 16M 
 
============================= 
cat meminfo 
 
MemTotal:      3629392 kB 
MemFree:       2907752 kB 
Buffers:         32120 kB 
Cached:         358672 kB 
SwapCached:          0 kB 
Active:         434180 kB 
Inactive:       242340 kB 
HighTotal:     2749072 kB 
HighFree:      2096336 kB 
LowTotal:       880320 kB 
LowFree:        811416 kB 
SwapTotal:     7815544 kB 
SwapFree:      7815544 kB 
Dirty:            3200 kB 
Writeback:           0 kB 
AnonPages:      285700 kB 
Mapped:          13596 kB 
Slab:            22544 kB 
SReclaimable:    12436 kB 
SUnreclaim:      10108 kB 
PageTables:       6608 kB 
NFS_Unstable:        0 kB 
Bounce:              0 kB 
WritebackTmp:        0 kB 
CommitLimit:   9630240 kB 
Committed_AS:   962492 kB 
VmallocTotal:   114680 kB 
VmallocUsed:      6236 kB 
VmallocChunk:   108004 kB 
HugePages_Total:     0 
HugePages_Free:      0 
HugePages_Rsvd:      0 
HugePages_Surp:      0 
Hugepagesize:     4096 kB

ilvista · 12-26-2010, 04:23 PM

I've had the same problem in the past.what i did ;i installed ATOP on my server to monitor my cpu and ram utilization.it's a nice tool.

in my case ,the mysqld was causing the problem.and it was overloding the CPU.
so try ATOP to eliminate this possibility.

good luck

gcan · 12-27-2010, 06:15 AM

I changed Apache configuration file and the problem is gone. New settings:

PHP Code:



<IfModule prefork.c> 
StartServers       15 
MinSpareServers    10 
MaxSpareServers   20 
ServerLimit      512 
MaxClients       512 
MaxRequestsPerChild  0 
</IfModule>

It's very strange. For years I was using Apache's default settings and never experienced speed problems.