Remote Monitoring & Management Help

MySQL Check

The Check monitors key MySQL (v5.0 and above) performance indicators - concurrent open connections,  memory pages flush wait time, slow queries execution, etc - generating an Alert where any of these settings exceed the threshold value. The Check queries the server for information and does not stop and start or restart MySQL.

Prerequisites

  • MySQL must be installed and running on the monitored device
  • The user the Linux Monitoring Agent is running under must have permissions to execute SHOW STATUS on the MySQL database server

MySQL Password

The Check can query a password protected MySQL instance where there is a MySQL options file setup. For example, create ~/.my.cnf with the following contents:

[client]

user=aMysqlUsername

password=password

host=localhost

Check configuration

The Check is configured via the Dashboard:

Add

  1. Select the device in the north pane of the Dashboard
  2. Go to the Checks tab
  3. From the Add Check drop-down
  4. Click Add DSC Check > MySQL Check
  5. Enter the upper threshold values (listed below)
  6. OK to save and apply

Edit

  1. Select the device in the north pane of the Dashboard
  2. Go to the Checks tab
  3. Choose the target MySQL Check in the lower pane
  4. From the Checks drop-down, or right-click context menu
  5. Go to Edit Check
  6. Amend the threshold settings
  7. OK to save and apply

When adding or editing a Check the new settings are downloaded to the Agent the next time it communicates back to the Dashboard and applied when the Check runs after that.

Delete

  1. Select the device in the north pane of the Dashboard
  2. Go to the Checks tab
  3. Choose the target MySQL Check in the lower pane
  4. From the Checks drop-down, or right-click context menu
  5. Go to Delete Check
  6. Enter the password of the user you have logged on to the Dashboard under to confirm deletion

  7. OK to save and apply

Enter upper thresholds for:

Meaning

Client Connections        

The number of clients that have currently open connections to the server.

Temporary tables

The number of temporary tables that have been created on disk instead of in-memory.

First row read requests

The number of times a table handler made a request to read the first row of a table index.

Memory pages flush wait time

The number of times MySQL has to wait for memory pages to be flushed.

Filesystem access for indexes

The number of filesystem accesses MySQL performed to fetch database indexes.

Concurrent open connections

The number of connections MySQL has had open at the same time since the server was last restarted.

Concurrent open tables

The number of tables that are currently open.

Full join queries        

The number of full joins MySQL has performed to satisfy client queries.

Slow queries execution

The number of queries that have taken longer than usual to execute.

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