Tales From A Lazy Fat DBA

Den of an Oracle DB Performance freak & a fan of PostgreSQL & Cassandra …. \,,/

  • Likes

    • 149,223
  • Archives

  • Categories

  • Subscribe

  • Advertisements
  • Prashant Dixit is the FatDBA

  • Follow Tales From A Lazy Fat DBA on WordPress.com
  • My Twitter Feeds

  • Disclaimer!

    FatDBA or Oracle ‘Ant’ is an independent web-blog/site.The experiences, Test cases, views, and opinions expressed in this website are my own and does not reflect the views or opinions of my employer.

    This site is independent of and does not represent Oracle Corporation in any way. Oracle does not officially sponsor, approve, or endorse this site or its content.
    Product and company names mentioned in this website may be the trademarks of their respective owners.

MYSQL startup error: [ERROR] Fatal error: mysql.user table is damaged.

Posted by FatDBA on November 15, 2017

Hi Mates,

While working with one of the client for his brand new installation i’ve encountered a weird problem while starting the MYSQL (5.7.20) daemon on RHEL6 where the MYSQLD service failed to start with below errors or issues captured in error logs.

[root@dixitlab ~]# service mysqld start
MySQL Daemon failed to start.
Starting mysqld: [FAILED]

Snippet from the error Logs:

2017-11-15T10:21:03.957212Z 0 [Note] InnoDB: File ‘./ibtmp1’ size is now 12 MB.
2017-11-15T10:21:11.147615Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2017-11-15T10:21:11.147902Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2017-11-15T10:21:11.291204Z 0 [Note] InnoDB: Creating sys_virtual system tables.
2017-11-15T10:21:11.300921Z 0 [Note] InnoDB: sys_virtual table created
2017-11-15T10:21:11.301245Z 0 [Note] InnoDB: Waiting for purge to start
2017-11-15T10:21:11.354201Z 0 [Note] InnoDB: 5.7.20 started; log sequence number 0
2017-11-15T10:21:11.354623Z 0 [Note] Plugin ‘FEDERATED’ is disabled.
2017-11-15T10:21:11.354976Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 9560ms. The settings might not be optimal. (flushed=0 and evicted=0, during the time.)
2017-11-15T10:21:11.355390Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2017-11-15T10:21:11.569467Z 0 [Warning] System table ‘plugin’ is expected to be transactional.
2017-11-15T10:21:11.570388Z 0 [Note] Salting uuid generator variables, current_pid: 29102, server_start_time: 1510741261, bytes_sent: 0,
2017-11-15T10:21:11.570971Z 0 [Note] Generated uuid: ‘b3e664f7-c9ee-11e7-9b23-000c29593ffb’, server_start_time: 8191484773744281275, bytes_sent: 44900352
2017-11-15T10:21:11.571109Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: b3e664f7-c9ee-11e7-9b23-000c29593ffb.
2017-11-15T10:21:11.573332Z 0 [Warning] Gtid table is not ready to be used. Table ‘mysql.gtid_executed’ cannot be opened.
2017-11-15T10:21:11.573745Z 0 [Warning] Failed to set up SSL because of the following SSL library error: SSL context is not usable without certificate and private key
2017-11-15T10:21:11.574116Z 0 [Note] Server hostname (bind-address): ‘*’; port: 3306
2017-11-15T10:21:11.574540Z 0 [Note] IPv6 is available.
2017-11-15T10:21:11.574745Z 0 [Note] – ‘::’ resolves to ‘::’;
2017-11-15T10:21:11.574891Z 0 [Note] Server socket created on IP: ‘::’.

2017-11-15T10:21:11.580607Z 0 [ERROR] Fatal error: mysql.user table is damaged. Please run mysql_upgrade.
2017-11-15T10:21:11.580879Z 0 [ERROR] Aborting

So after taking a look at the error log it’s quite clear that the startup failed with a ‘Fatal Error’ which in turn crashed the entire startup process for the instance with error message “mysql.user table is damaged”. At the same time it gives a solution or a fix to run the mysql_upgrade, but as the instance failed to start it was not possible to execute the command.

Here is what happened when i tried to execute the mysql_upgrade

bash-4.1$ mysql_upgrade
mysql_upgrade: Got error: 2002: Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (2) while connecting to the MySQL server
Upgrade process encountered error and will not continue.

*******SOLUTION*********
As a fix to avoid this deadlock, I’ve started the server with skip-grant-tables option.
This can be done by adding the ‘skip-grant-tables’ line to the my.cnf (Configuration File) withing section [mysqld].

bash-4.1$ su –
Password:
[root@dixitlab ~]#
[root@dixitlab ~]# vi /etc/my.cnf

[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
innodb_data_file_path = ibdata1:10M:autoextend
skip-grant-tables

Now, lets try to start the mysql server now.

[root@dixitlab ~]# service mysqld start
Starting mysqld: [ OK ]
[root@dixitlab ~]#

Boom! It worked. Now quickly try to run the mysql_upgrade step to fix the initial problem.

-bash-4.1$ mysql_upgrade
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
Checking system database.
mysql.columns_priv OK
mysql.db OK
mysql.engine_cost OK
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.gtid_executed OK
mysql.help_category OK
mysql.help_keyword OK
mysql.help_relation OK
mysql.help_topic OK
mysql.host OK
mysql.innodb_index_stats OK
mysql.innodb_table_stats OK
mysql.ndb_binlog_index OK
mysql.plugin OK
mysql.proc OK
mysql.procs_priv OK
mysql.proxies_priv OK
mysql.server_cost OK
mysql.servers OK
mysql.slave_master_info OK
mysql.slave_relay_log_info OK
mysql.slave_worker_info OK
mysql.slow_log OK
mysql.tables_priv OK
mysql.time_zone OK
mysql.time_zone_leap_second OK
mysql.time_zone_name OK
mysql.time_zone_transition OK
mysql.time_zone_transition_type OK
mysql.user OK
Upgrading the sys schema.
Checking databases.
sys.sys_config OK
Upgrade process completed successfully.
Checking if update is needed.
-bash-4.1$
-bash-4.1$

Now when it is done, lets revert the changes that we have made to the configuration file and remove the skip-grant-table entry from my.cnf file and restart the MYSQLD service.

[root@dixitlab ~]# vi /etc/my.cnf
[root@dixitlab ~]#
[root@dixitlab ~]#
[root@dixitlab ~]# service sqld restart
sqld: unrecognized service
[root@dixitlab ~]# service mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]
[root@dixitlab ~]#

Lets try to connect with the database now.

bash-4.1$
bash-4.1$ mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.20 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.

mysql>

Hope This Helps
Prashant Dixit

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

 
%d bloggers like this: