store | blogs | forums | twitter | facebook | wiki | downloads | support portal
Atomic Secure Linux
It is currently Sun Aug 18, 2019 5:14 pm

» Feed - Atomicorp

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 7 posts ] 
Author Message
 Post subject: Slow server
Unread postPosted: Wed May 17, 2017 4:57 am 
Offline
Forum Regular
Forum Regular

Joined: Tue Jul 15, 2008 2:38 pm
Posts: 805
Location: Sweden
I have a server Centos 7, with ASL which is running really slow. I cannot really understand why. When I say really slow, I don't mean always or with all applications, but for some. the most important one is Wordpress. It seems like the time to first byte takes forever. Disks seems ok, memory ok, CPU ok. I don't really know where to look. Is it Apache or Nginx? Is it ASL? Is it MySQL/MariaDB? Any suggestions?

Really appreciate your help!

Screenshot from NR, showing CPU and disks.
https://ibb.co/bzOot5


Top
 Profile  
Reply with quote  
 Post subject: Re: Slow server
Unread postPosted: Sat May 20, 2017 12:58 pm 
Offline
Atomicorp Staff - Site Admin
Atomicorp Staff - Site Admin
User avatar

Joined: Thu Feb 07, 2008 7:49 pm
Posts: 4081
Location: Chantilly, VA
That sounds a DNS issue, are you running any DNS based rules or do you have apache setup with HostnamesLookup enabled?

_________________
Michael Shinn
Atomicorp - Security For Everyone


Top
 Profile  
Reply with quote  
 Post subject: Re: Slow server
Unread postPosted: Sat May 20, 2017 1:54 pm 
Offline
Forum Regular
Forum Regular

Joined: Tue Jul 15, 2008 2:38 pm
Posts: 805
Location: Sweden
Sure, I use the DNS-based rules from ASL. Never heard of hostbasedlookup. Is it useful?


Top
 Profile  
Reply with quote  
 Post subject: Re: Slow server
Unread postPosted: Mon May 22, 2017 10:46 am 
Offline
Forum Regular
Forum Regular

Joined: Tue Jul 15, 2008 2:38 pm
Posts: 805
Location: Sweden
Some benchmarks

Code:
oscar@server22 ~]$ ab -c 20 -n 1000 http://www.xyz.se/index.php
This is ApacheBench, Version 2.3 <$Revision: 1430300 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking www.xyz.se (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        nginx
Server Hostname:        www.xyz.se
Server Port:            80

Document Path:          /index.php
Document Length:        0 bytes

Concurrency Level:      20
Time taken for tests:   177.387 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Non-2xx responses:      1000
Total transferred:      437000 bytes
HTML transferred:       0 bytes
Requests per second:    5.64 [#/sec] (mean)
Time per request:       3547.736 [ms] (mean)
Time per request:       177.387 [ms] (mean, across all concurrent requests)
Transfer rate:          2.41 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.3      0       3
Processing:   704 3501 847.4   3306    8010
Waiting:      704 3501 847.4   3306    8010
Total:        707 3501 847.4   3306    8010

Percentage of the requests served within a certain time (ms)
  50%   3306
  66%   3656
  75%   3893
  80%   4087
  90%   4521
  95%   4930
  98%   6131
  99%   6827
 100%   8010 (longest request)


Top
 Profile  
Reply with quote  
 Post subject: Re: Slow server
Unread postPosted: Thu May 25, 2017 7:17 pm 
Offline
Atomicorp Staff - Site Admin
Atomicorp Staff - Site Admin
User avatar

Joined: Thu Feb 07, 2008 7:49 pm
Posts: 4081
Location: Chantilly, VA
In that case, if your symptom is that your server has no load, no I/O or memory issues, and a web page takes a long time to load then the DNS server you're using is slow. The most common cause is using a remote DNS server for your local DNS lookups as described in this article:

https://wiki.atomicorp.com/wiki/index.p ... S_resolver

Check to make sure you have a local DNS server to do all your lookups, and remove any remote DNS servers from your config.

_________________
Michael Shinn
Atomicorp - Security For Everyone


Top
 Profile  
Reply with quote  
 Post subject: Re: Slow server
Unread postPosted: Thu Jul 27, 2017 10:24 am 
Offline
New Forum User
New Forum User

Joined: Thu Jul 27, 2017 10:17 am
Posts: 1
Location: sri lanka
Hey biggles i am having a similar issue...any improvement??
SymptomsDrugssubchorionichemorrhage


Last edited by Markk786 on Sun Aug 13, 2017 9:41 am, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject: Re: Slow server
Unread postPosted: Mon Jul 31, 2017 5:44 pm 
Offline
Forum Regular
Forum Regular

Joined: Tue Jul 15, 2008 2:38 pm
Posts: 805
Location: Sweden
Yes!

I had set it to use a local dns, but a setting in CentOS 7 made it rewrite the resolve file on every restart or ASL reconfiguration. When I fixed that the server is working as it should.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

» Feed - Atomicorp

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group