Skip to main content

Too many connections in TIME_WAIT state

Too many connections in TIME_WAIT state:
If you seeing a lot of connections in  TIME_WAIT state then each socket in TIME_WAIT consumes some memory in the kernel, usually somewhat less than an ESTABLISHED socket. But it may increase the load in server.
For solving this you need to do the following on the server,
Login to the server via SSH
Then enter the following command, it will append the values for timeout in the server,
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout
echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle
Also you need to edit the file,
 /etc/sysctl.conf
and add the timeout and recycle values in it.
vi /etc/sysctl.conf
And add the following values to the file
net.ipv4.tcp_fin_timeout=30
net.ipv4.tcp_tw_recycle = 1

Comments

Post a Comment

Popular posts from this blog

Modsecurity block rule for XMLRPC and wp-login attack

SecAction phase:1,nolog,pass,initcol:ip=%{REMOTE_ADDR},initcol:user=%{REMOTE_ADDR},id:5000134  <Locationmatch "/wp-login.php">  SecRule user:bf_block "@gt 0" "deny,status:401,log,id:5000135,msg:'ip address blocked for 5 minutes, more than 10 login attempts in 3 minutes.'"  SecRule RESPONSE_STATUS "^302" "phase:5,t:none,nolog,pass,setvar:ip.bf_counter=0,id:5000136"  SecRule RESPONSE_STATUS "^200" "phase:5,chain,t:none,nolog,pass,setvar:ip.bf_counter=+1,deprecatevar:ip.bf_counter=1/180,id:5000137"  SecRule ip:bf_counter "@gt 10" "t:none,setvar:user.bf_block=1,expirevar:user.bf_block=300,setvar:ip.bf_counter=0"  </Locationmatch>  SecAction phase:1,nolog,pass,initcol:ip=%{REMOTE_ADDR},initcol:user=%{REMOTE_ADDR},id:5000234  <Locationmatch "/xmlrpc.php">  SecRule user:bf_block "@gt 0" "deny,status:401,log,id:5000235,msg:'ip address blocked for 5 m...
Post a Comment
Read more

Apache tuning documentation

Apache bench marking ======================= Things or checklist to be considered before the test     CPU: avoid power-saving mode. cpufreq-set -g performance.     File descriptors: raise the limit to (at least) the number of concurrent connections you wish to handle, using ulimit -n in your shell, or setrlimit(RLIMIT_NOFILE) in your server. Beware, some systems forbid you to raise the limit, you might need to investigate a bit to find how to unlock it.     Disable the logs of your server (you do not want to lose time logging thousands of requests instead of answering them).     Raise /proc/sys/net/somaxconn to the number of concurrent connections you want to handle. To understand why this is necessary, read the technical report or the excellent paper Measuring the Capacity of a Web Server (Banga and Druschel, Usenix 97). More on the fascinating topic of the accept() queue can be found in accept()able Strategies for Im...
Post a Comment
Read more

Fix the permission and ownership

Usage ./scripts user1 user2 user3 You can also run a server-wide loop like this: for i in `ls -A /var/cpanel/users` ; do ./scripts $i ; done  code =========== #!/bin/bash if [ "$#" -lt "1" ];then echo "Must specify user" exit; fi USER=$@ for user in $USER do HOMEDIR=$(egrep "^${user}:" /etc/passwd | cut -d: -f6) if [ ! -f /var/cpanel/users/$user ]; then echo "$user user file missing, likely an invalid user" elif [ "$HOMEDIR" == "" ];then echo "Couldn't determine home directory for $user" else echo "Setting ownership for user $user" chown -R $user:$user $HOMEDIR chmod 711 $HOMEDIR chown $user:nobody $HOMEDIR/public_html $HOMEDIR/.htpasswds chown $user:mail $HOMEDIR/etc $HOMEDIR/etc/*/shadow $HOMEDIR/etc/*/passwd echo "Setting permissions for user $USER" find $HOMEDIR -type f -exec chmod 644 {} \; -print find $HOMEDIR -type d -exec chmod 755 {} \; -print find $HOMEDIR ...
Post a Comment
Read more