Thesqldump error on bash script

backupMySQLmysqldump

I'm trying to run a bash script to backup my database with Cronjob.

# Backup and compress each database
for database in $mysql_databases
do
  if [ "${database}" == "information_schema" ] || [ "${database}" == "performance_schema" ]; then
        additional_mysqldump_params1="--single-transaction"
  else
        additional_mysqldump_params=""
  fi
  echo "Creating backup of \"${database}\" database"
  mysqldump ${additional_mysqldump_params} --user=${mysql_user} --password=${mysql_password} ${database} | gzip > "${backup_dir}/${database}.gz"
  chmod 600 "${backup_dir}/${database}.gz" ${additional_mysqldump_params1}
done

but the --single-transaction option is not recognized

Best Answer

OBSERVATION #1

It is not recognized because of a typo

You have

  if [ "${database}" == "information_schema" ] || [ "${database}" == "performance_schema" ]; then
        additional_mysqldump_params1="--single-transaction"
  else
        additional_mysqldump_params=""
  fi

It should be

  if [ "${database}" == "information_schema" ] || [ "${database}" == "performance_schema" ]; then
        additional_mysqldump_params="--single-transaction"
  else
        additional_mysqldump_params=""
  fi

Please change the additional_mysqldump_params1 to additional_mysqldump_params

OBSERVATION #2

You have

chmod 600 "${backup_dir}/${database}.gz" ${additional_mysqldump_params1}

It should read

chmod 600 "${backup_dir}/${database}.gz"

Please remove additional_mysqldump_params1 from that line of code

OBSERVATION #3

There is no need to mysqldump information_schema or performance_schema databases

The INFORMATION_SCHEMA database is made of up in-memory temporary tables. They are dynamically generated and populated on mysqld startyo.
The PERFORMANCE_SCHEMA database is for the instrumentation of measuring performance. Each individual MySQL instance is responsible for populating it with instrumentation data when it is in use.

Related Solutions

Mysql – Users complain that system runs slow when thesqldump is in progress

There is a known issue in Windows, that when you push a large file to another server all the memory ends up getting allocated to the System cache instead of the user processes. You can look in the Physical Memory (MB) section of task manager to see how much memory is allocated to the system cache.

This can be solved by backing up to a local disk, then having the remote machine pull that file.

MySQL – How to Detect a Running mysqldump

Your only hope in this scenario is to have the PROCESS privilege.

The SUPER privilege allows you to kill processes. Naturally, you don't want that. On the other hand, the PROCESS privilege allows you to see the processlist.

According to the MySQL Documentation on the PROCESS Privilege

The PROCESS privilege pertains to display of information about the threads executing within the server (that is, information about the statements being executed by sessions). The privilege enables use of SHOW PROCESSLIST or mysqladmin processlist to see threads belonging to other accounts; you can always see your own threads.

OK, Big Deal. The PROCESS Privilege lets you see the Process List. How does that help?

You can quickly detect a mysqldump in progress when you run SHOW PROCESSLIST; and see a pattern like this in the Info field:

SELECT /*!40001 SQL_NO_CACHE */ * FROM

If you have the PROCESS Privilege and are running MySQL 5.1+, you can run this query:

select COUNT(1) mysqldumpThreads
from information_schema.processlist
where info like 'SELECT /*!40001 SQL_NO_CACHE */%';

Here is a sample output:

mysql> select COUNT(1) mysqldumpThreads
    -> from information_schema.processlist
    -> where info like 'SELECT /*!40001 SQL_NO_CACHE */%';
+------------------+
| mysqldumpThreads |
+------------------+
|                1 |
+------------------+
1 row in set (0.00 sec)

All you need to do is query for that number. If you get a nonzero, mysqldump must be running.

Give it a Try !!!