Wednesday, May 17, 2017

Find file older than n days with full absolute path

This command will find the files log, out and txt file as in this example which is older than n days which is defined in parameter -mtime and print the absolute path of the files found.

find `pwd` -maxdepth 1 -mtime +n -type f \( -name "*.log*" -o -name "*.out*" -o -name "*.txt" \)

Examples:

Find and print absolute path of the files which are 7 days or 30 days old

find `pwd` -maxdepth 1 -mtime +7 -type f \( -name "*.log*" -o -name "*.out*" -o -name "*.txt" \)

find `pwd` -maxdepth 1 -mtime +30 -type f \( -name "*.log*" -o -name "*.out*" -o -name "*.txt" \)

We can play with -mtime parameter to get other desired result

Friday, May 5, 2017

List or See MySQL command or query history: MySql Command Or Query History : Command Line

MySql store the history of command or queries in .mysql_history file in the user directory, suppose you want to see the history of commands or SQL queries which <username> has executed we can either login to that user or from another user we can type:

cat ~/.mysql_history

Suppose current user is logged in as root or any user if it has Sudo permission then we can give command

cat /home/username/.mysql_history

Wednesday, May 3, 2017

Configuring freeIPA Kerberos in Cloudera Manager : Cloudera Manager + freeIPA + Kerberos

  1. Create a user in free IPA using command line or WebUI
    • Suppose this user is Hadoop
  2. Now add this user to admin and trust user group in IPA user groups.
  3. Generate a Kerberos ticket for this created user, run this command at the server where Cloudera Manager is hosted or installed.
    • ipa-getkeytab -s <your ipa server name> -p <hadoop@your-realm.name> -k keytabfile.keytab 
    • e.g.:
      • ipa-getkeytab -s ipa.server.com -p hadoop@SERVER.COM -k cdh.keytab
    • kinit with the the user hadoop
      • kinit hadoop@SERVER.COM
      • It will ask you the password; pass the password set while creating the keytab.
      • It will now ask you to change the password, set a new password
      • Use kdestroy to remove the hadoop user cache with old password.
      • again do kinit with new password
      • kinit hadoop@SERVER.COM
      • Again get the keytab files using command, in order to get the latest keytab file with update password.
      • ipa-getkeytab -s ipa.server.com -p hadoop@SERVER.COM -k cdh.keytab
  4. Copy this keytab file /etc/cloudera-scm-server directory of any path which should be accessible to Cloudera Manager.
  5. Once you get the cdh.keytab file change its ownership to cloudera-scm user
    • chown cloudera-scm: cloudera-scm cdh.keytab
  6. Download the custom keytab retrieval script file from: 
  7. Save this script to some location which should be accessible to Cloudera Manager for example:
  8. The parameter which you need to change in this file follows:
    • IPA_SERVER=ipa.server.com
    • REALM=SERVER.COM
    • KEYTAB_FILE=/etc/cloudera-scm-server/cdh.keytab
    • CM_PRINC=hadoop@$REALM
    • There is a line near line number 39 in this script which says
      • ipa service-add $PRINCIPAL
    • Make change to this like add --force at the end of this line(This is use to override the restriction in freeIPA) then line will look like
      • ipa service-add $PRINCIPAL  --force
  9. Login the server freeIPA is installed/login to freeIPA for example ipa.server.com
      • Start kadmin.local as
      •  kadmin.local -x ipa-setup-override-restrictions
      •  This will login as root/admin@SERVER.COM
  10.  Add a new principle for Cloudera-manager here
      •  addprinc –pw <passwordforuser> cloudera-scm/admin@SERVER.COM
      • e.g.:
      • addprinc –pw cdhpassword Cloudera-scm/admin@SERVER.COM
  11. Once this principle is added successfully, go to Cloudera manager Web UI <your-clouderamanage- server:7180>
  12.  Go to administration security/ or from the cluster dropdown menu choose enable Kerberos
  13. In the resulting page enter the required details, and in the page where it says KDC account manager credentials enter
      • First text box Username : cloudera-scm/admin
      •  2nd Text box Your REALM : SERVER.COM
      • Third Box Password : passwordforuser
  14.  Once this step successes move forward to generate other service principal which Cloudera Manager will generate automatically if this step is successful.


Hope this will help.


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