mysql reset root password

http://www.cyberciti.biz/tips/recover-mysql-root-password.html

on fedora: /etc/init.d/mysqld
on debian: /etc/initd/mysql

/etc/init.d/mysql stop
mysqld_safe --skip-grant-tables &
mysql -u root 
mysql> use mysql;
mysql> update user set password=PASSWORD("NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit
/etc/init.d/mysql start

OpenLDAP

Install on ubuntu: 

sudo apt-get install slapd ldap-utils

sudo apt-get install phpldapadmin

sudo service apache2 restart
http://host/phpldapadmin

Reference

openldap-server.html
One correction: please quote the binding dn below in bash.

OpenLDAPServer

How to change RootDN 

/etc/ldap/slapd.d/cn=config/olcDatabase={1}hdb.ldif

olcDatabase={1}hdb.ldif:olcRootDN: cn=admin,dc=example,dc=com

How to change RootPWD

• generate hash with slappasswd  
• change RootPwd using the above generated hash. 
• sudo service slapd restart

Clean Import 

• service stop slapd
• clean slapd db: rm -f /var/lib/ldap/*
• slapadd -l .ldif
• /var/lib/ldap$ sudo chown openldap:openldap * (make sure the ownership belongs to openldap)
• service start slapd

Add entries

sudo ldapadd -x -D "cn=admin,dc=example,dc=com" -W -f frontend.example.com.ldif 

(it will prompt for password)

Search

• ldapsearch -x -b '' -s base '(objectclass=*)' namingContexts
• ldapsearch -x -b 'dc=example,dc=com' '(objectclass=*)'

Install python-ldap

• sudo apt-get install build-essential python-dev libldap2-dev libssl-dev libsasl2-dev
• pip install python-ldap

increase Linux max number of FD limits

how to increase max fd

System level

• sudo sysctl -w fs.file-max=100000
• to survive the reboot: sudo vi /etc/sysctl.conf: fs.file-max = 100000

User level

• sudo vi /etc/security/limits.conf:
• uid soft nofile 4096
• uid hard nofile 10240

VisualVM remote monitoring JVM

JMX set up for JVM argument



-Dcom.sun.management.jmxremote.port=8086
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false

JVM GC tuning

HeapDump
-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/home/blah/pid.hprof

nginx load balance

http {
 upstream mylb {
   server 127.0.0.1:9999;
   server 127.0.0.1:9998;
  }

  server {
   proxy_pass http://mylb
  }

}