Apache Issue On CentOS 6

Home » CentOS » Apache Issue On CentOS 6
CentOS 8 Comments

I am facing a problem with Apache on CentOS 6

Apache 2.2.19 is complied from source.

I see so many reading requests in Apache status page, as per my previous experience this “reading request” issue mainly comes when any of the internet route having any problem and it request takes time to completely reach to Apache, but this time there is no network issue.

I have ran same setup on CentOS 5 it works well, but on CentOS 6 it show
60%+ reading requests, web site has 20-25 requests per second that becomes
80+

I also tried to upgrade Apache to 2.2.24 but it is same on new version as well.

Anyone else has experienced this issue?

8 thoughts on - Apache Issue On CentOS 6

  • I’d recommend you to sort out the connections. Find out if they are coming from the same client or the same subnet of the clients. Doing a simple tcpdump capture to analyze the data seeing if it’s a good R or a bad R.

    Don’t really think it’s because of the version.

    ———-

  • I have already checked but all requests are from different IP’s and even different subnet When there are less requests it works ok even if there are more than 60%
    reading requests but during peak time when concurrent requests goes beyond
    150, due to reading requests it becomes 300+ requests processing at the same time and that then Apache stop responding as maxclient is set to 300. CPU load also goes up and thing become very slow.

  • Did you check mpm settings of httpd-mpm.conf ?

    default response client value for 2.2… versions is 150 and 2
    proccessor for simultaneously response ….

    applying httpd-mpm.conf in httpd.conf and changing mpm thread settings will help you…

  • I did a quick test on el5 and el6 with these package,

    httpd-2.2.3-43.el5.CentOS
    httpd-2.2.15-15.el6.CentOS.1.i686

    I kept the configuration as what it is in default. The index page is about 7k, 100 connections per second. I barely find the connection is marked as R. Mostly C and _. This is done by ab from httpd.

    I also did a quick test with slow attack. It’s basically slowing the client itself to collect the data from the server. I did 200 connections per second. My server is ok seems. A little bit slow, but not too much.

    el5

    RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
    RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
    RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
    RRRRRRRRCWS……………………………………………..

    el6

    RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
    RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
    RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
    RRRCRRRRCCCCCCCRWCCCCCWCCCCCCWWCCCCCCCCCCCCCCCCCCCCCCCCCCC……

    I also did the capture on the network traffic that I can find out the connections are doing something bad. You may follow the lead here as I
    mentioned.

    ———-

  • Yes, they do because I’m using slow access to attack my servers. To your environment, you can use tcpdump to capture one connection to check if it’s the slow access attack.

    If it’s an attack, we focus on fixing that part. If it’s the code problem, then, we can get back to the httpd daemon checking what it goes wrong.

    ———-

  • I was not able to reproduce it while sending so many requests from ab or any other tool, it only appears when requests come from browser, I had posted this question to Apache users as well and someone told that it is due to Chrome uses preconnection, though this feature was available on Chrome since version 7, till kernel version 2.6.31.14 these preconnection requests were not coming to Apache status page but from 2.6.32 they started appearing on Apache status.

    Following thread also talks about preconnection https://code.google.com/p/chromium/issues/detail?id

LEAVE A COMMENT