Tom Smykowski's questions

I have a Lighttpd server (on Centos) and would like to display 4 graphs: lighttpd traffic, lighttpd requests per second, CPU usage and MEM usage. I've set place for rrd database for lighttpd config like this:

rrdtool.binary = "/usr/bin/rrdtool"
rrdtool.db-name = "/var/www/lighttpd.rrd"

And put into my WWW cgi-bin sh file that gets data from lighttpd RRD file and creates graphs of traffic and requests per second like this:

#!/bin/sh

RRDTOOL=/usr/bin/rrdtool
OUTDIR=//var/www/graphs
INFILE=/var/www/lighttpd.rrd
OUTPRE=lighttpd-traffic
WIDTH=400
HEIGHT=100

DISP="-v bytes --title TrafficWebserver \
        DEF:binraw=$INFILE:InOctets:AVERAGE \
        DEF:binmaxraw=$INFILE:InOctets:MAX \
        DEF:binminraw=$INFILE:InOctets:MIN \
        DEF:bout=$INFILE:OutOctets:AVERAGE \
        DEF:boutmax=$INFILE:OutOctets:MAX \
        DEF:boutmin=$INFILE:OutOctets:MIN \
        CDEF:bin=binraw,-1,* \
        CDEF:binmax=binmaxraw,-1,* \
        CDEF:binmin=binminraw,-1,* \
        CDEF:binminmax=binmaxraw,binminraw,- \
        CDEF:boutminmax=boutmax,boutmin,- \
        AREA:binmin#ffffff: \
        STACK:binmax#f00000: \
        LINE1:binmin#a0a0a0: \
        LINE1:binmax#a0a0a0: \
        LINE2:bin#efb71d:incoming \
        GPRINT:bin:MIN:%.2lf \
        GPRINT:bin:AVERAGE:%.2lf \
        GPRINT:bin:MAX:%.2lf \
        AREA:boutmin#ffffff: \
        STACK:boutminmax#00f000: \
        LINE1:boutmin#a0a0a0: \
        LINE1:boutmax#a0a0a0: \
        LINE2:bout#a0a735:outgoing \
        GPRINT:bout:MIN:%.2lf \
        GPRINT:bout:AVERAGE:%.2lf \
        GPRINT:bout:MAX:%.2lf \
        " 

$RRDTOOL graph $OUTDIR/$OUTPRE-hour.png -a PNG --start -14400 $DISP -w $WIDTH -h $HEIGHT
$RRDTOOL graph $OUTDIR/$OUTPRE-day.png -a PNG --start -86400 $DISP -w $WIDTH -h $HEIGHT
$RRDTOOL graph $OUTDIR/$OUTPRE-month.png -a PNG --start -2592000 $DISP -w $WIDTH -h $HEIGHT

OUTPRE=lighttpd-requests

DISP="-v req --title RequestsperSecond -u 1 \
        DEF:req=$INFILE:Requests:AVERAGE \
        DEF:reqmax=$INFILE:Requests:MAX \
        DEF:reqmin=$INFILE:Requests:MIN \
        CDEF:reqminmax=reqmax,reqmin,- \
        AREA:reqmin#ffffff: \
        STACK:reqminmax#00f000: \
        LINE1:reqmin#a0a0a0: \
        LINE1:reqmax#a0a0a0: \
        LINE2:req#00a735:requests" 

$RRDTOOL graph $OUTDIR/$OUTPRE-hour.png -a PNG --start -14400 $DISP -w $WIDTH -h $HEIGHT
$RRDTOOL graph $OUTDIR/$OUTPRE-day.png -a PNG --start -86400 $DISP -w $WIDTH -h $HEIGHT
$RRDTOOL graph $OUTDIR/$OUTPRE-month.png -a PNG --start -2592000 $DISP -w $WIDTH -h $HEIGHT

Basically it's not my script, i get it from somewhere from the internet. Now i would like to do the same for CPU usage and MEM usage. I don't like to use any additional packages!

As you can see lighttpd populates lighttpd.rrd file with traffic data and requests per second. Now i would like to the system to populate second rrd file with CPU and MEM usage, so i can add to sh file code to generate graphs for this data.

How can I populate RRD file with CPU and MEM usage data? Please, NO THIRD-PARTY tools !

I'm searching for a tool designed for LAMP server that combines server Error log, Access log, slow query log, takes time of execution of PHP scripts,traffic and req per sec statistics (for example from RRDTool) and put it all into one chronological list.

Do you know this kind of tool?

Possible Duplicate:
How to fetch ./configure parameters used at last time?

Some time ago under Centos, Bash I've compiled a program from source files. Now I need to compile with again with a new flag.

Is there any way to find out what command i used last time to compile this program under Linux Centos?

I have a Centos 5 system with Lighttpd and fastcgi enabled. It does log access but does not log errors. I have Internal Server Error 500 and no info in log and when I try to open not -existing file also - no info in error log. How to enable it properly?

Below is list of modules that I've enabled:

server.modules              = (
                               "mod_rewrite",
                               "mod_redirect",
                               "mod_alias",
#                                "mod_access",
#                               "mod_cml",
#                               "mod_trigger_b4_dl",
#                               "mod_auth",
                               "mod_status",
                               "mod_setenv",
                               "mod_fastcgi",
#                               "mod_webdav",
#                               "mod_proxy_core",
#                               "mod_proxy_backend_fastcgi",
#                               "mod_proxy_backend_scgi",
#                               "mod_proxy_backend_ajp13",
#                               "mod_simple_vhost",
#                               "mod_evhost",
#                               "mod_userdir",
#                               "mod_cgi",
#                               "mod_compress",
#                               "mod_ssi",
#                               "mod_usertrack",
#                               "mod_expire",
#                               "mod_secdownload",
#                               "mod_rrdtool",
                                "mod_accesslog" )

Here are setting of debugging:

## enable debugging
#debug.log-request-header     = "enable"
#debug.log-response-header    = "enable"
#debug.log-request-handling   = "enable"
debug.log-file-not-found     = "enable"
#debug.log-condition-handling = "enable"

Setting of path to error and access log:

## where to send error-messages to
server.errorlog             = "/home/lxadmin/httpd/lighttpd/error.log"

#### accesslog module
accesslog.filename          = "/home/lxadmin/httpd/lighttpd/ligh.log"

Settings of fastcgi:

fastcgi.debug = 1

fastcgi.server = ( ".php" => ((
                     "bin-path" => "/usr/bin/php-cgi",
                     "socket" => "/tmp/php.socket",
                     "max-procs" => 12,
                     "bin-environment" => (
                         "PHP_FCGI_CHILDREN" => "2",
                         "PHP_FCGI_MAX_REQUESTS" => "500"
                         )
                 )))

And in included config file I have:

server.errorlog    =  "/home/httpd/mywebsite.com/stats/mywebsite.com-error_log"

What comes to log files:

/home/httpd/mywebsite.com/stats/
-rw-r--r-- 1 apache apache 5173239 May 16 11:34 mywebsite.com-custom_log
-rwxrwxrwx 1 root   root         0 Mar 27  2009 mywebsite.com-error_log

/home/lxadmin/httpd/lighttpd/
-rwxrwxrwx  1 apache apache    2184 Apr 22 22:59 error.log
-rwxrwxrwx  1 apache apache 6088621 May 16 11:26 ligh.log

I gave error logs chmod 777 for a try to check if it's the issue, but apparently it's not.

So my question is: what to do to have error log enabled?

When I try to yum install anything I get:

-bash-3.2# yum install strace
Loading "fastestmirror" plugin
Determining fastest mirrors
 * dag: apt.sw.be
 * lxlabsupdate: download.lxlabs.com
 * rpmforge: fr2.rpmfind.net
 * lxlabslxupdate: download.lxlabs.com
YumRepo Warning: not using ftp, http[s], or file for repos, skipping - 5.2 is not a valid release or hasnt been released yet
removing mirrorlist with no valid mirrors: //var/cache/yum/base/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: base

In /etc/yum.repos.d I have files:

CentOS-Base.repo         CentOS-Media.repo  mirrors-rpmforge
CentOS-Base.repo.rpmnew  lxlabs.repo        rpmforge.repo

CentOS-Base.repo:

# CentOS-Base.repo
#
# This file uses a new mirrorlist system developed by Lance Davis for CentOS.
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client.  You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#

[base]
name=CentOS-$releasever - Base
mirrorlist=http://mirrorlist.centos.org/?release=5.2&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

#released updates
[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?release=5.2&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful

[extras]
name=CentOS-$releasever - Extras
mirrorlist=http://mirrorlist.centos.org/?release=5.2&arch=$basearch&repo=extras
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

[centosplus]
name=CentOS-$releasever - Plus
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&rep$
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

[dag]
name=Dag RPM Repository for Centos
baseurl=http://apt.sw.be/redhat/el$releasever/en/$basearch/dag

[addons]
name=CentOS-$releasever - Addons
mirrorlist=http://mirrorlist.centos.org/?release=5.2&arch=$basearch&repo=addons
#baseurl=http://mirror.centos.org/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
enabled=1

How to fix it?

I have Lighttpd on Centos 5 with Fcgi and Memcached. Periodically, once per week or two i get internal server error 500 and i must manually restart lighttpd to get it to work again.

In my lighttpd config I've defined error log file:

server.errorlog             = "/home/lxadmin/httpd/lighttpd/error.log"

But when I open it, it has no rows for last days, only one month ago.

So my question is how to diagnose what is the issue and how to enable error log for my configuration?

I have a Facebook app written in PHP. It has 150 page views per minute and will have up to 300 page views per minute till end of this year. While getting more PV I start to have problems with scalability and therefore I would like to ask you for an advice how to scale to sucessfully handle 300 PV / minute.

My application is a quizz like app, it is hosted on a VPS that can use:

• 100% of one core 2,6 GHz processor
• 500 MB, up to 2 GB of RAM (cat /proc/user_beancounters said that I have really privvmpages = 500 MB, free -m shows 2 GB)

Configuration of my VPS goes like this:

• Centos 5
• Lighttpd
• Memcached
• APC
• MySQL
• PHP using FastCGI

While last months I've acomplished to optimize MySQL, Lighttpd and PHP configuration using some tutorials provided on the internet. I've managed to use extensively Memcached so many requests dropped to 1ms, and those not handled by memcache take up to 300 ms. I've added good indexes to MySQL so it's not on the fire range of users.

For some time above optimizations was enough to handle new requests, but lately due to increasing popularity of application, I've noticed that some requests take longer than 3 seconds and in critical burst my Lighttpd just says f*** you and users get Internal Server Error 500.

I've managed to find (I'll know this today for sure) a solution to fix error 500 by setting:

"PHP_FCGI_MAX_REQUESTS" => "500"

But still scalability issue is not resolved. I need to be able to handle 2 x more requests than now. And I think how to do this. Here are solutions that I came up today:

1. Upgrage VPS to 3,3 GHz on 2 cores
2. Buy another VPS and move database there
3. Ask someone for help (that I do now)

I can buy at my VPS distributor a bigger plan that has 3,3 Ghz in place of 2,6 Ghz that I have now and on 2 cores not one. It will take some more money, but can it help me? How to calculate if it will handle 300 PV?

Second idea I have is to buy another VPS and move database there. It should give gain of CPU and Memory for FastCGI processes and Database process. But how to know if it's better to spawn another server or to buy bigger plan for this I have now?

So I come into 3 point - to ask someone. So here I am - a programmer, not a administrator, with a very huge scalability problem and ask for your help.

I would like to know how can I calculate how many PV per minute my current VPS can handle - it would help me decide. Because if 300 PV is beyond my current VPS abilities - I can think right away on other solution and not messing more with configuration.

Secondly - if it's possible that my VPS can handle more requests - it's issue of configuration - than I would need some help from someone with more knowledge in this issue to help me set up config right. I can provide this config here or send someone by email and hope to know from you who has time and knowledge to help me with this. I don't have time for more experiments in this matter.

Lastly - if it is beyond of my VPS abilities I would like to know from you how to decide if I should upgrade my VPS or spawn another server? What solution will be better for 300 PV target?

If you came to this point of my questions thank you very much in advance for asking. Your help, advice or contacts to persons who can help in in this issue will be very helfull for me!

I would like to save ApacheBench (ab) tool on linux to a file. When I run it with -v 2 it displays some results in my ssh window. How to move these data into a file and make sure that it will not display on ssh no more? I've tried > file.txt 2>&1 but it does not work and still display data in my ssh window.

I use:

ab -n 10000 -c 200 http://mywebsite.com > file.txt 2>&1

In my DNS administration software I have a option to create a new DNS zone and option to add records to existing DNS zone that I use for my first domain.

I would like to add next doman in DNS. Should I put it into existing zone or create new one? I'm a beginner in DNS configuration so a little explanation here would be great.

I am calling an 'executable' on Linux. One way by console and another from a PHP script. They both call other executables (I see it by the version of the file). So I need a way to display a path to the executable that will be called when I try to run it. How do I do this on Linux?

I try to make my subdomain operable on Centos 5 and Tinydns. I've added :

+en.mydomain.com:ip_address:3600

saved and did:

make

with no errors. But ping does not show this subdomain. What can I do to make my subdomain working using subdomain and how to diagnoze what is wrong now?

Accorindg to @womble i provide results of "Checking addresses of your computers" from: http://cr.yp.to/djbdns/run-server.html

1. Reverse lookups: 12 my_ip.in-addr.arpa: (not good?).
2. I get some netstat results
3. Tinydns-get size is 92 so it's less than 512.
4. Dnsq on en.mydomain.com issued on my server ip returns valid answer
5. Dnsqr en.mydomain.com does not return answer (it's not good right?)
6. /var/tinydns/log/main folder is empty so i can not diagnose log file (how to enable it?)

7. Dnstrace shows:

   0:.:.:start:NS:.:. 0:.:.:start:A:.:my_ip 1:en.mydomain.com:.:my_ip:tx 1:en.mydomain.com:.:my_ip:A:en.mydomain.com:my_ip 1:en.mydomain.com:.:my_ip:NS:mydomain.com:ns.lxlabs.com 1:en.mydomain.com:.:my_ip:NS:mydomain.com:ns1.lxlabs.com 1:en.mydomain.com:.:my_ip:answer:en.mydomain.com 86400 A my_ip 1:ns.lxlabs.com:.:my_ip:tx 1:ns.lxlabs.com:.:my_ip:ALERT:query failed; timed out 1:ns1.lxlabs.com:.:my_ip:tx 1:ns1.lxlabs.com:.:my_ip:ALERT:query failed; timed out

Hope this help to provide answer.

I have a CentOS 5 with Lightppd installed. Also I have MySQL on board. I lately discovered high traffic:

http://img686.imageshack.us/img686/8596/traff.jpg

Could you please tell me how to diagnose what is cause of this traffic? I didn't do anything that would explain it.

I have a VPS with CentOS 5. I would like to create backup of:

• all my config files
• tweaks of database, php, server a databases
• cron settings
• website files
• installed applications and their settings (?)

What files should i take into account?

I don't want to miss any file that will be necessary to restore fast my webserver in case of any failure.

And I don't want to create whole backup because entire VPS has like 30 GB of data.

This is a Canonical Question about DNS/Hostnames resolution to IPs/Ports

Example 1

I'm running a web server on port 80 and another on port 87. I would like to use DNS so that www.example.com goes to port 87. How can I accomplish this using DNS only?

Example 2

I'm running a service on my server on a non-standard port. How can I get clients to connect to this non-standard port automatically? Can I use DNS? Is there some application specific support where DNS could indicate the IP and Port?

Example 3

Do some application protocols specifically support hostname awareness, and allow special actions to be taken based on this information? Are there other questions on Server Fault that cover some of these?

_{Commandeering: This question was originally asking about running IIS and Apache on the same server, but the same concepts can be applied to any server software receiving connections from clients. The Answers below describe the technical problems and solutions of using DNS and application protocol support to assign a port number for a client to connect.}

I have a .htaccess in my root of website that looks like this:

RewriteEngine On

RewriteCond %{HTTP_HOST} !^www\.mydomain\.pl [NC]
RewriteCond %{HTTP_HOST} ^(?:www\.)?([a-z0-9_-]+)\.mydomain\.pl [NC]
RewriteRule ^/?$ /index.php?run=places/%1 [L,QSA]

RewriteCond %{REQUEST_URI} !^/index.php$
RewriteCond %{REQUEST_URI} !^/images/
RewriteCond %{REQUEST_URI} !^/upload/
RewriteCond %{REQUEST_URI} !^/javascript/
RewriteRule ^(.*)$ /index.php?runit=$1 [L,QSA]

I've installed custom guest book in folder guests and now I would like to disable rules above for this one specific folder. So that when I type:

mydomain.pl/guests

I would like to go normally to actual folder guests. I understand that I need to somehow disable rules above for guests subfolder, but how do I do this?

I have a problem with Lighttpd because someone started to use some Web downloader from very good connection and it blocked my whole website. Is there any way to protect Lighttpd from DDOS attacks and flooding?

I've investigated my Lighttpd access log and found some strange things listed below. I do not know if it's good or bad, but bearshare? I was never or these sites I use my Centos only for website hosting. Could you help me understand these logs?

87.219.0.18 download.bearshare.com - [26/Sep/2009:12:41:37 +0200] "GET http://download.bearshare.com/BSInstall.exe HTTP/1.0" 404 345 "-" "Mozilla/3.0 (compatible)"
87.219.17.44 proxyworld.ifrance.com - [26/Sep/2009:20:13:53 +0200] "GET http://proxyworld.ifrance.com/azenv.php HTTP/1.1" 404 345 "http://proxyworld.ifrance.com/azenv.php" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
87.219.17.44 proxyworld.ifrance.com - [26/Sep/2009:20:44:12 +0200] "GET http://proxyworld.ifrance.com/azenv.php HTTP/1.1" 404 345 "http://proxyworld.ifrance.com/azenv.php" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
118.168.162.245 - - [27/Sep/2009:12:43:58 +0200] "CONNECT 220.132.13.98:25 HTTP/1.0" 501 357 "-" "-"
125.224.203.130 203.188.201.253:25 - [28/Sep/2009:00:28:09 +0200] "CONNECT 203.188.201.253:25 HTTP/1.1" 501 357 "-" "-"
69.46.23.47 174.34.157.98 - [28/Sep/2009:23:48:54 +0200] "GET http://174.34.157.98/proxychecker/check.cgi?action=getinfo HTTP/1.1" 404 345 "http://www.google.com/search?hl=ru&q=free+proxy+checker&sourceid=navclient-ff&ie=UTF-8" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
125.224.203.130 203.188.201.253:25 - [28/Sep/2009:23:58:14 +0200] "CONNECT 203.188.201.253:25 HTTP/1.1" 501 357 "-" "-"
124.133.252.204 www.yahoo.com - [29/Sep/2009:10:25:59 +0200] "GET http://www.yahoo.com/ HTTP/1.1" 200 1953 "-" "Mozilla/5.0 (compatible; MSIE 5.01; Win2000)"
124.11.136.231 72.14.221.111:25 - [29/Sep/2009:14:59:51 +0200] "CONNECT 72.14.221.111:25 HTTP/1.1" 501 357 "-" "-"
125.224.197.97 203.188.201.253:25 - [01/Oct/2009:01:30:56 +0200] "CONNECT 203.188.201.253:25 HTTP/1.1" 501 357 "-" "-"