Sponsored Content
Operating Systems Linux Red Hat apache high cpu load on high traffic Post 302560709 by ieth0 on Friday 30th of September 2011 03:50:33 PM
Old 09-30-2011
there are many things you need to check, if your traffic usage ( in case of correct configuration ) isnt bigger than your server resource then:

1) you need to turn off KeepAlive
2) decrease MaxRequestsPerChild to 30
3) decrease Timeout if its bigger than 90seconds
4) check your sysctl.conf or use this pre-configured sysctl :
Code:
#Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Disables packet forwarding
net.ipv4.ip_forward=0

# Disables IP source routing
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.lo.accept_source_route = 0
net.ipv4.conf.eth0.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0

# Enable IP spoofing protection, turn on source route verification
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.lo.rp_filter = 1
net.ipv4.conf.eth0.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

# Disable ICMP Redirect Acceptance
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.lo.accept_redirects = 0
net.ipv4.conf.eth0.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0

# Enable Log Spoofed Packets, Source Routed Packets, Redirect Packets
net.ipv4.conf.all.log_martians = 0
net.ipv4.conf.lo.log_martians = 0
net.ipv4.conf.eth0.log_martians = 0

# Disables IP source routing
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.lo.accept_source_route = 0
net.ipv4.conf.eth0.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0

# Enable IP spoofing protection, turn on source route verification
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.lo.rp_filter = 1
net.ipv4.conf.eth0.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

# Disable ICMP Redirect Acceptance
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.lo.accept_redirects = 0
net.ipv4.conf.eth0.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0

# Disables the magic-sysrq key
kernel.sysrq = 0

# Decrease the time default value for tcp_fin_timeout connection
net.ipv4.tcp_fin_timeout = 15

# Decrease the time default value for tcp_keepalive_time connection
net.ipv4.tcp_keepalive_time = 1800

# Turn off the tcp_window_scaling
net.ipv4.tcp_window_scaling = 0

# Turn off the tcp_sack
net.ipv4.tcp_sack = 0

# Turn off the tcp_timestamps
net.ipv4.tcp_timestamps = 0

# Enable TCP SYN Cookie Protection
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 3

# Enable ignoring broadcasts request
net.ipv4.icmp_echo_ignore_broadcasts = 1

# Enable bad error message Protection
net.ipv4.icmp_ignore_bogus_error_responses = 1

# Log Spoofed Packets, Source Routed Packets, Redirect Packets
net.ipv4.conf.all.log_martians = 1

# Increases the size of the socket queue (effectively, q0).
net.ipv4.tcp_max_syn_backlog = 1024

# Increase the tcp-time-wait buckets pool size
net.ipv4.tcp_max_tw_buckets = 1440000

# Allowed local port range
net.ipv4.ip_local_port_range = 16384 65536

net.ipv4.netfilter.ip_conntrack_max = 196605000


vm.dirty_background_ratio = 20
vm.dirty_ratio = 60

#reduce the number of time_wait connections
#these 3 lines can reduce your time_wait count by several hundred percent.
#however you should not use the following lines in a NATed configuration.
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 30

vm.swappiness=0

then run:
Code:
sysctl -p

5) check .htaccess of websites, sometimes they are using much cpu
6) check whether you are not under attack , use mod_security , mod_evasive , firewall like csf , etc...
7) check enabled modules , and exclude unnecessaries.
8) if your websites are running on php and your apache compiled with mod_suphp/phpSUEXEC/mod_fcgi/ ,etc they are 4 times slower than mod_php , switch to mod_php
9) use caches like eAccelerator , xcache , ...

finally, the information you gave isnt much that we rely on to help you resolve the problem, google for optimizing apache to find more on this.
This User Gave Thanks to ieth0 For This Post:
 

10 More Discussions You Might Find Interesting

1. AIX

Application high CPU load

after a long period of running, the network application's CPU load in our syst em increase slowly, the failed at the end. we use "truss" tool to trace the process, found that it processes something like "semop" ,"semctl","thread_waitlock","kread" kernel call . The trace log file looks like the... (0 Replies)
Discussion started by: Frank2004
0 Replies

2. UNIX for Advanced & Expert Users

Sun: High kernel usage & very high load averages

Hi, I am seeing very high kernel usage and very high load averages on my system (Although we are not loading much data to our database). Here is the output of top...does anyone know what i should be looking at? Thanks, Lorraine last pid: 13144; load averages: 22.32, 19.81, 16.78 ... (4 Replies)
Discussion started by: lorrainenineill
4 Replies

3. HP-UX

HIgh Load

Hi All. In my production server the load is very high. normally it used to be less than 1,but now it is more than 5. I am new to unix all together. I want to know what is the reason behind high load. and if it is high what is the impact? (4 Replies)
Discussion started by: jyoti
4 Replies

4. Red Hat

High cpu load average

Hi Buddies, Thanx for reading my first post... After googling a lot and searching so many forums I am feeling down a bit... Please don't mind my ignorence, and my grammer ... :) My server is running RHEL 2.6.9-5.EL. The cpu load is going higher than roof, almost 100 sometimes. I am... (2 Replies)
Discussion started by: squid04
2 Replies

5. Solaris

nestat on server involved in high traffic network

Hi All My Server is doing a very intense netowrk traffic operations and the cards are under very high pressure. I need to call NETSTAT on the shell. Do you know whether this command, under high pressure, might have some impact on the server traffic or can I proceed without any problem? (2 Replies)
Discussion started by: manustone
2 Replies

6. UNIX for Advanced & Expert Users

What's a high load for my system?

I'm not sure if this belong in dummies or advanced so I made my best guess. Go easy on me if I get it wrong. I'm trying to determine what a high load for my system is. I run a php/mysql web server with a dedicated host. The host has a Intel Xeon 3110 (Dual Core) processor. Our load seems to... (5 Replies)
Discussion started by: vanguard
5 Replies

7. Shell Programming and Scripting

what would a script include to find CPU's %system time high and user time high?

Hi , I am trying to :wall: my head while scripting ..I am really new to this stuff , never did it before :( . how to find cpu's system high time and user time high in a script?? thanks , help would be appreciated ! :) (9 Replies)
Discussion started by: sushwey
9 Replies

8. Shell Programming and Scripting

Restart debian server if one specific process has more than 10 seconds have high cpu load

Hi, could someone give me an example for a debian server script? I need to check a process if the process has a high cpu load (top). If yes the whole server needs to reboot. Thats it, nothing more. ;) Hope someone could help me. Regards woisch (2 Replies)
Discussion started by: woisch
2 Replies

9. Red Hat

CPU high - apache real server OK, virtual server not

Got two RHEL servers - one real and one virtual/cloud. Both run apache web server. When traffic is applied, CPU seems to go quite high on virtual one (20%) but real is not really affected. Worry is that a further increase in traffic will see a problem. Experience of RHEL is limited. Whats... (2 Replies)
Discussion started by: psychocandy
2 Replies

10. UNIX for Dummies Questions & Answers

I have a 12 core Linux cpu but the load is really high on this box, hovering around 50.

I have a 12 core linux cpu but the load is really high on this box, hovering around 50. What configuration changes do we need to make so that system have no bottleneck. (13 Replies)
Discussion started by: Moon1234
13 Replies
All times are GMT -4. The time now is 02:29 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy