Bug #85095 MySQL service fails to start after a power failure
Submitted: 21 Feb 2017 7:23 Modified: 22 Feb 2017 9:00
Reporter: Suhail Gupta Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server: InnoDB storage engine Severity:S2 (Serious)
Version:5.6.27 OS:Windows
Assigned to: CPU Architecture:Any
Tags: frm, idb, MySQL, power failure

[21 Feb 2017 7:23] Suhail Gupta
Description:
Each time there is a power failure, MySQL service fails to start. The reason is that IDB files get corrupted. We have to manually restore each table by:
 - First restoring the structure of each table (FRM) in the database
 - Recreate the tables in a database.
 - Remove the new IDB files by discarding the tablespace for each table.
 - Copy the old IDB files.
 - Import tablespace for each table.
 - After the above step, restarting the MySQL service, we are able to access the data, initially corrupted.

This happens on the client end and we have manually restore each table by asking them to send us the data folder in the MySQL installation. What makes the scenario more complicated is that client machine works in a constrained environment, where they do not have access to the internet and they first have to copy the data folder on a separate drive and then mail us from a different location.

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Window event logs prints the following error:

InnoDB: Attempted to open a previously opened tablespace. Previous tablespace mam/content_info uses space ID: 2 at filepath: .\mam\content_info.ibd. Cannot open tablespace mysql/innodb_index_stats which uses space ID: 2 at filepath: .\mysql\innodb_index_stats.ibd

For more information, see Help and Support Center at http://www.mysql.com.  
============================================================================

If I directly try to run mysql.exe from the bin directory, it says:
ERROR 2003 (HY000): Can't connect to MySQL server on 'localhost' (10061)

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Here is my.ini file:

# Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# You can copy this file to
# /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options (in this
# installation this directory is C:\mysql\data) or
# ~/.my.cnf to set user-specific options.
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password	= your_password
port		= 3306
socket		= /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[wampmysqld]
port		= 3306
socket		= /tmp/mysql.sock
key_buffer_size = 16M
max_allowed_packet = 1M
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M
basedir=c:/wamp/bin/mysql/mysql5.6.17
log-error=c:/wamp/logs/mysql.log
datadir=c:/wamp/bin/mysql/mysql5.6.17/data

lc-messages-dir=c:/wamp/bin/mysql/mysql5.6.17/share

# Change your locale here !
#lc-messages=fr_FR
lc-messages=en_GB
# Avoid warning
explicit_defaults_for_timestamp = TRUE

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking

# Disable Federated by default
skip-federated

# Replication Master Server (default)
# binary logging is required for replication
#log-bin=mysql-bin

# binary logging format - mixed recommended
#binlog_format=mixed

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id	= 1

# Replication Slave (comment out master section to use this)

# New for MySQL 5.6 if no slave
skip-slave-start

#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
#    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
#    where you replace <host>, <user>, <password> by quoted strings and
#    <port> by the master's port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
#    MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables' values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =   <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =   <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =   <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin

# Point the following paths to different dedicated disks
#tmpdir		= /tmp/		
#log-update 	= /path-to-dedicated-directory/hostname

# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = C:\mysql\data/
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = C:\mysql\data/
#innodb_log_arch_dir = C:\mysql\data/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 16M
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 5M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50

[mysqldump]
quick
max_allowed_packet = 16M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[isamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[myisamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

[mysqld]
port=3306
explicit_defaults_for_timestamp = TRUE
basedir="C:/Venera/Media Automation Manager/mysql/"
log-error="C:/Venera/Media Automation Manager/logs/mysql.log"
datadir="C:/Venera/Media Automation Manager/mysql/data/"
#innodb_force_recovery = 4

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How to repeat:
Cut off the power supply.
[22 Feb 2017 9:00] MySQL Verification Team
We're sorry, but the bug system is not the appropriate forum for asking help on using MySQL products. We don't see any evidence that indicates that this is a defect in MySQL code. Your problem is not the result of a bug.

Support on using our products is available both free in our forums at http://forums.mysql.com/ and for a reasonable fee direct from our skilled support engineers at http://www.mysql.com/support/

Thank you for your interest in MySQL.