Skip to main content

Link to database cannot be established

Arsalan Ansari
Its not often but am getting error (usually 2 or more time a day) when i am trying to open my site "Link to database cannot be established: SQLSTATE[HY000] [2006] MySQL server has gone away" at this stage my site not respond anything. If i restart mysql service ever thing back to normal but not for long. What should i need to do to resolve that issue??? Configuration--- CENTOS 6.7 x86_64 vmware WHM 54.0 (build 16) MYSQL Server version: 5.5.48-cll

Comments

8 comments

Date Votes
  • ssfred
    Hello :) Please check the current MySQL activity during the time of the issue by executing the following command From Shell: #mysqladmin proc stat From MySQL Shell mysql> show processlist; Also check the MySQL server logs /var/lib/mysql/hostname.err for any error messages.
    0
  • Arsalan Ansari
    hello ssfred Thanks for the reply. the only thing what i checked is MySQL server logs but i will check you suggested command during the issue. please check MySQL server logs. - Removed Please Attach Images to Your Posts -
    0
  • twhiting9275
    What do the logs say at the time?
    0
  • Arsalan Ansari
    Hi twhiting, Thanks for the response. My current logs say at the time as follow...
    150729 01:37:24 mysqld_safe Starting mysqld daemon with databases from /var/lib/ mysql 150729 1:37:24 [Note] Plugin 'FEDERATED' is disabled. 150729 1:37:24 InnoDB: The InnoDB memory heap is disabled 150729 1:37:24 InnoDB: Mutexes and rw_locks use GCC atomic builtins 150729 1:37:24 InnoDB: Compressed tables use zlib 1.2.3 150729 1:37:24 InnoDB: Using Linux native AIO 150729 1:37:24 InnoDB: Initializing buffer pool, size = 128.0M 150729 1:37:24 InnoDB: Completed initialization of buffer pool InnoDB: The first specified data file ./ibdata1 did not exist: InnoDB: a new database to be created! 150729 1:37:24 InnoDB: Setting file ./ibdata1 size to 10 MB InnoDB: Database physically writes the file full: wait... 150729 1:37:24 InnoDB: Log file ./ib_logfile0 did not exist: new to be created InnoDB: Setting log file ./ib_logfile0 size to 5 MB InnoDB: Database physically writes the file full: wait... 150729 1:37:24 InnoDB: Log file ./ib_logfile1 did not exist: new to be created InnoDB: Setting log file ./ib_logfile1 size to 5 MB InnoDB: Database physically writes the file full: wait... InnoDB: Doublewrite buffer not found: creating new InnoDB: Doublewrite buffer created InnoDB: 127 rollback segment(s) active. InnoDB: Creating foreign key constraint system tables InnoDB: Foreign key constraint system tables created 150729 1:37:25 InnoDB: Waiting for the background threads to start 150729 1:37:26 InnoDB: 5.5.42 started; log sequence number 0 150729 1:37:26 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306 150729 1:37:26 [Note] - '0.0.0.0' resolves to '0.0.0.0'; 150729 1:37:26 [Note] Server socket created on IP: '0.0.0.0'. 150729 1:37:26 [Note] Event Scheduler: Loaded 0 events 150729 1:37:26 [Note] /usr/sbin/mysqld: ready for connections. Version: '5.5.42-cll' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Co mmunity Server (GPL) 150729 1:37:32 [Note] /usr/sbin/mysqld: Normal shutdown 150729 1:37:32 [Note] Event Scheduler: Purging the queue. 0 events 150729 1:37:34 InnoDB: Starting shutdown... 150729 1:37:35 InnoDB: Shutdown completed; log sequence number 1595675 150729 1:37:35 [Note] /usr/sbin/mysqld: Shutdown complete 150729 01:37:35 mysqld_safe mysqld from pid file /var/lib/mysql/srv.server.com.p id ended 150729 01:37:35 mysqld_safe Starting mysqld daemon with databases from /var/lib/ mysql 150729 1:37:35 [Note] Plugin 'FEDERATED' is disabled. 150729 1:37:35 InnoDB: The InnoDB memory heap is disabled 150729 1:37:35 InnoDB: Mutexes and rw_locks use GCC atomic builtins 150729 1:37:35 InnoDB: Compressed tables use zlib 1.2.3 150729 1:37:35 InnoDB: Using Linux native AIO 150729 1:37:35 InnoDB: Initializing buffer pool, size = 128.0M 150729 1:37:35 InnoDB: Completed initialization of buffer pool 150729 1:37:35 InnoDB: highest supported file format is Barracuda. 150729 1:37:35 InnoDB: Waiting for the background threads to start 150729 1:37:36 InnoDB: 5.5.42 started; log sequence number 1595675 150729 1:37:36 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306 150729 1:37:36 [Note] - '0.0.0.0' resolves to '0.0.0.0'; 150729 1:37:36 [Note] Server socket created on IP: '0.0.0.0'. 150729 1:37:36 [Note] Event Scheduler: Loaded 0 events 150729 1:37:36 [Note] /usr/sbin/mysqld: ready for connections. Version: '5.5.42-cll' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Co mmunity Server (GPL) 150729 2:42:29 [Note] /usr/sbin/mysqld: Normal shutdown 150729 2:42:29 [Note] Event Scheduler: Purging the queue. 0 events 150729 2:42:31 [Warning] /usr/sbin/mysqld: Forcing close of thread 71 user: 'e ximstats' 150729 2:42:31 [Warning] /usr/sbin/mysqld: Forcing close of thread 64 user: 'l eechprotect' 150729 2:42:31 InnoDB: Starting shutdown... 150729 2:42:33 InnoDB: Shutdown completed; log sequence number 1683063 150729 2:42:33 [Note] /usr/sbin/mysqld: Shutdown complete 150729 02:42:33 mysqld_safe mysqld from pid file /var/lib/mysql/srv.server.com.p id ended
    and currently my site is down. - Removed - please help..
    0
  • Arsalan Ansari
    just restarted mysql service and my site back to normal.
    0
  • cPanelMichael
    just restarted mysql service and my site back to normal.

    Hello, I'm happy to see your website is running well. Could you verify if the issue is now resolved? Thank you.
    0
  • Arsalan Ansari
    Hi, Yes its back to normal but not for long time as i mentioned in my earlier post. That's not a solution
    0
  • ssfred
    Hello :) Check whether there is any memory availability issues. Some times OOM killer may trigger termination of MySQL processes, if the primary memory availability is low and MySQL is showing a high memory usage. You check it using the command #egrep -i "oom|kill|mysql" /var/log/messages
    0

Please sign in to leave a comment.

Didn't find what you were looking for?

New post