Category: Scripting

maxclients.sh Script For Apache

May 3, 2014

This script attempts to look at Apache memory usage and recommend a stable setting for MaxClients.

#!/bin/bash

PROCNAME=httpd
PARENTPIDS=`comm -12 <(ps -C $PROCNAME -o ppid | sort -u) <(ps -C $PROCNAME -o pid | sort -u)`

for ParPID in $PARENTPIDS; do
  SUM=0
  COUNT=0
  for x in `ps f --ppid $ParPID -o rss | tail -n +2`; do
    SUM=$(( $SUM + $x ))
    COUNT=$(( $COUNT + 1 ))
  done

  MEMPP=$(( $SUM / $COUNT / 1024 ))
  FREERAM=$(( `free | tail -2 | head -1 | awk '{print $4}'` / 1024 ))
  APACHERAM=$(( $SUM / 1024 ))
  APACHEMAX=$(( $APACHERAM + $FREERAM ))

  (
  echo
  echo "Info for the following parent apache process:"
  echo "  "`ps f --pid $ParPID -o command | tail -n +2`
  echo
  echo "Current # of apache processes:        $COUNT"
  echo "Average memory per apache process:    $MEMPP MB"
  echo "Free RAM (including cache & buffers): $FREERAM MB"
  echo "RAM currently in use by apache:       $APACHERAM MB"
  echo "Max RAM available to apache:          $APACHEMAX MB"
  echo
  echo "Theoretical maximum MaxClients:  $(( $APACHEMAX / $MEMPP ))"
  echo "Recommended MaxClients:          $(( $APACHEMAX / 10 * 9 / $MEMPP ))"
  echo
  )
done

#!/bin/bash

PROCNAME=httpd

PARENTPIDS=`comm -12 <(ps -C $PROCNAME -o ppid | sort -u) <(ps -C $PROCNAME -o pid | sort -u)`

for ParPID in $PARENTPIDS; do

SUM=0

COUNT=0

for x in `ps f --ppid $ParPID -o rss | tail -n +2`; do

SUM=$(( $SUM + $x ))

COUNT=$(( $COUNT + 1 ))

done

MEMPP=$(( $SUM / $COUNT / 1024 ))

FREERAM=$(( `free | tail -2 | head -1 | awk '{print $4}'` / 1024 ))

APACHERAM=$(( $SUM / 1024 ))

APACHEMAX=$(( $APACHERAM + $FREERAM ))

(

echo

echo "Info for the following parent apache process:"

echo " "`ps f --pid $ParPID -o command | tail -n +2`

echo

echo "Current # of apache processes: $COUNT"

echo "Average memory per apache process: $MEMPP MB"

echo "Free RAM (including cache & buffers): $FREERAM MB"

echo "RAM currently in use by apache: $APACHERAM MB"

echo "Max RAM available to apache: $APACHEMAX MB"

echo

echo "Theoretical maximum MaxClients: $(( $APACHEMAX / $MEMPP ))"

echo "Recommended MaxClients: $(( $APACHEMAX / 10 * 9 / $MEMPP ))"

echo

)

done

getpass.sh Bash Script

May 3, 2014

Simple bash script for generating random passwords. We didn’t write this and don’t know exactly where it came from.

#!/bin/bash

MATRIX="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
LENGTH=$1

while [ "${n:=1}" -le "$LENGTH" ]
# ==> Recall that := is "default substitution" operator.
# ==> So, if 'n' has not been initialized, set it to 1.
do
       PASS="$PASS${MATRIX:$(($RANDOM%${#MATRIX})):1}"
       # ==> Very clever, but tricky.

       # ==> Starting from the innermost nesting...
       # ==> ${#MATRIX} returns length of array MATRIX.

       # ==> $RANDOM%${#MATRIX} returns random number between 1
       # ==> and [length of MATRIX] - 1.

       # ==> ${MATRIX:$(($RANDOM%${#MATRIX})):1}
       # ==> returns expansion of MATRIX at random position, by length 1.
       # ==> See {var:pos:len} parameter substitution in Chapter 9.
       # ==> and the associated examples.

       # ==> PASS=... simply pastes this result onto previous PASS (concatenation).

       # ==> To visualize this more clearly, uncomment the following line
       #                 echo "$PASS"
       # ==> to see PASS being built up,
       # ==> one character at a time, each iteration of the loop.

       let n+=1
       # ==> Increment 'n' for next pass.
done

echo -n "$PASS"      # ==> Or, redirect to a file, as desired.

exit 0

#!/bin/bash

MATRIX="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

LENGTH=$1

while [ "${n:=1}" -le "$LENGTH" ]

# ==> Recall that := is "default substitution" operator.

# ==> So, if 'n' has not been initialized, set it to 1.

PASS="$PASS${MATRIX:$(($RANDOM%${#MATRIX})):1}"

# ==> Very clever, but tricky.

# ==> Starting from the innermost nesting...

# ==> ${#MATRIX} returns length of array MATRIX.

# ==> $RANDOM%${#MATRIX} returns random number between 1

# ==> and [length of MATRIX] - 1.

# ==> ${MATRIX:$(($RANDOM%${#MATRIX})):1}

# ==> returns expansion of MATRIX at random position, by length 1.

# ==> See {var:pos:len} parameter substitution in Chapter 9.

# ==> and the associated examples.

# ==> PASS=... simply pastes this result onto previous PASS (concatenation).

# ==> To visualize this more clearly, uncomment the following line

# echo "$PASS"

# ==> to see PASS being built up,

# ==> one character at a time, each iteration of the loop.

let n+=1

# ==> Increment 'n' for next pass.

done

echo -n "$PASS" # ==> Or, redirect to a file, as desired.

exit 0

Apache Watch Script

May 3, 2014

Here’s a trivial old script that I sometimes use to monitor for rough processes running on the apache user:

#!/bin/bash

TEST=`ps auxw | grep apache | grep -v "httpd" | grep -v apachewatch | grep -v grep `

if [ "$TEST" != "" ]; then
echo "test";
        echo "Subject: RP apache alert
To: support@reliablepenguin.com

Alert ... something fishy on RP ...

-------
$TEST
-------

" | /usr/sbin/sendmail support@reliablepenguin.com

fi

#!/bin/bash

TEST=`ps auxw | grep apache | grep -v "httpd" | grep -v apachewatch | grep -v grep `

if [ "$TEST" != "" ]; then

echo "test";

echo "Subject: RP apache alert

To: support@reliablepenguin.com

Alert ... something fishy on RP ...

-------

$TEST

-------

" | /usr/sbin/sendmail support@reliablepenguin.com

I seen several servers with high traffic PHP sites hosted on Plesk servers building up an excessive number of PHP session files in /var/lib/php/session. Typically we discover this problem when the server runs out of inodes on the root filesystem. Plesk provides a cronjob that runs hourly to clean up PHP session files:

/etc/cron.hourly/plesk-php-cleanuper

1	/etc/cron.hourly/plesk-php-cleanuper

For low traffic sites this script work just fine. But for high traffic sites with thousands of sessions per hour the script is too slow and can’t keep up with the rate that files are created. The problem is the script check each files using the “fuser” utility to determine if the file is in use. This is a slow process. So on these high traffic servers I’ve found it necessary to remove the “fuser” check. Edit /etc/cron.hourly/plesk-php-cleanuper and change this line:

[ -x /usr/lib64/plesk-9.0/maxlifetime ] && [ -d /var/lib/php/session ] && find /var/lib/php/session -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib64/plesk-9.0/maxlifetime) ! -execdir fuser -s {} &nbsp;2>/dev/null \;&nbsp;-delete

1	[ -x /usr/lib64/plesk-9.0/maxlifetime ] && [ -d /var/lib/php/session ] && find /var/lib/php/session -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib64/plesk-9.0/maxlifetime) ! -execdir fuser -s {}  2>/dev/null \; -delete

to:

[ -x /usr/lib64/plesk-9.0/maxlifetime ] && [ -d /var/lib/php/session ] && find /var/lib/php/session -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib64/plesk-9.0/maxlifetime) -delete

1	[ -x /usr/lib64/plesk-9.0/maxlifetime ] && [ -d /var/lib/php/session ] && find /var/lib/php/session -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib64/plesk-9.0/maxlifetime) -delete

Now the session cleanup will run smoothly.

Apache mod_fcgi on CentOS 6.4

February 6, 2014

There are a lot of tutorials on how to install mod_fcgi with suexec out there but many are incomplete, outdated or just don’t work. One that does work is here: http://www.howtoforge.com/how-to-set-up-apache2-with-mod_fcgid-and-php5-on-centos-6.2