Collect performance counters for Linux applications in Azure Monitor

This article provides details for configuring the Log Analytics agent for Linux to collect performance counters for specific applications into Azure Monitor. The applications included in this article are:

• MySQL
• Apache HTTP Server

MySQL

If MySQL Server or MariaDB Server is detected on the computer when the Log Analytics agent is installed, a performance monitoring provider for MySQL Server will be automatically installed. This provider connects to the local MySQL/MariaDB server to expose performance statistics. MySQL user credentials must be configured so that the provider can access the MySQL Server.

Configure MySQL credentials

The MySQL OMI provider requires a preconfigured MySQL user and installed MySQL client libraries in order to query the performance and health information from the MySQL instance. These credentials are stored in an authentication file that's stored on the Linux agent. The authentication file specifies what bind-address and port the MySQL instance is listening on and what credentials to use to gather metrics.

During installation of the Log Analytics agent for Linux the MySQL OMI provider will scan MySQL my.cnf configuration files (default locations) for bind-address and port and partially set the MySQL OMI authentication file.

The MySQL authentication file is stored at /var/opt/microsoft/mysql-cimprov/auth/omsagent/mysql-auth.

Authentication file format

Following is the format for the MySQL OMI authentication file

[Port]=[Bind-Address], [username], [Base64 encoded Password]
(Port)=(Bind-Address), (username), (Base64 encoded Password)
(Port)=(Bind-Address), (username), (Base64 encoded Password)
AutoUpdate=[true|false]

The entries in the authentication file are described in the following table.

Property	Description
Port	Represents the current port the MySQL instance is listening on. Port 0 specifies that the properties following are used for default instance.
Bind-Address	Current MySQL bind-address.
username	MySQL user used to use to monitor the MySQL server instance.
Base64 encoded Password	Password of the MySQL monitoring user encoded in Base64.
AutoUpdate	Specifies whether to rescan for changes in the my.cnf file and overwrite the MySQL OMI Authentication file when the MySQL OMI Provider is upgraded.

Default instance

The MySQL OMI authentication file can define a default instance and port number to make managing multiple MySQL instances on one Linux host easier. The default instance is denoted by an instance with port 0. All additional instances will inherit properties set from the default instance unless they specify different values. For example, if MySQL instance listening on port ‘3308’ is added, the default instance’s bind-address, username, and Base64 encoded password will be used to try and monitor the instance listening on 3308. If the instance on 3308 is bound to another address and uses the same MySQL username and password pair only the bind-address is needed, and the other properties will be inherited.

The following table has example instance settings

Description	File
Default instance and instance with port 3308.	0=127.0.0.1, myuser, cnBwdA== 3308=, , AutoUpdate=true
Default instance and instance with port 3308 and different user name and password.	0=127.0.0.1, myuser, cnBwdA== 3308=127.0.1.1, myuser2,cGluaGVhZA== AutoUpdate=true

MySQL OMI Authentication File Program

Included with the installation of the MySQL OMI provider is a MySQL OMI authentication file program which can be used to edit the MySQL OMI Authentication file. The authentication file program can be found at the following location.

/opt/microsoft/mysql-cimprov/bin/mycimprovauth

The following table provides details on the syntax for using mycimprovauth.

Operation	Example	Description
autoupdate false or true	mycimprovauth autoupdate false	Sets whether or not the authentication file will be automatically updated on restart or update.
default bind-address username password	mycimprovauth default 127.0.0.1 root pwd	Sets the default instance in the MySQL OMI authentication file. The password field should be entered in plain text - the password in the MySQL OMI authentication file will be Base 64 encoded.
delete default or port_num	mycimprovauth 3308	Deletes the specified instance by either default or by port number.
help	mycimprov help	Prints out a list of commands to use.
print	mycimprov print	Prints out an easy to read MySQL OMI authentication file.
update port_num bind-address username password	mycimprov update 3307 127.0.0.1 root pwd	Updates the specified instance or adds the instance if it does not exist.

The following example commands define a default user account for the MySQL server on localhost. The password field should be entered in plain text - the password in the MySQL OMI authentication file will be Base 64 encoded

sudo su omsagent -c '/opt/microsoft/mysql-cimprov/bin/mycimprovauth default 127.0.0.1 <username> <password>'
sudo /opt/omi/bin/service_control restart

Database Permissions Required for MySQL Performance Counters

The MySQL User requires access to the following queries to collect MySQL Server performance data.

SHOW GLOBAL STATUS;
SHOW GLOBAL VARIABLES:

The MySQL user also requires SELECT access to the following default tables.

• information_schema
• mysql.

These privileges can be granted by running the following grant commands.

GRANT SELECT ON information_schema.* TO ‘monuser’@’localhost’;
GRANT SELECT ON mysql.* TO ‘monuser’@’localhost’;

Define performance counters

Once you configure the Log Analytics agent for Linux to send data to Azure Monitor, you must configure the performance counters to collect. Use the procedure in Windows and Linux performance data sources in Azure Monitor with the counters in the following table.

Object Name	Counter Name
MySQL Database	Disk Space in Bytes
MySQL Database	Tables
MySQL Server	Aborted Connection Pct
MySQL Server	Connection Use Pct
MySQL Server	Disk Space Use in Bytes
MySQL Server	Full Table Scan Pct
MySQL Server	InnoDB Buffer Pool Hit Pct
MySQL Server	InnoDB Buffer Pool Use Pct
MySQL Server	InnoDB Buffer Pool Use Pct
MySQL Server	Key Cache Hit Pct
MySQL Server	Key Cache Use Pct
MySQL Server	Key Cache Write Pct
MySQL Server	Query Cache Hit Pct
MySQL Server	Query Cache Prunes Pct
MySQL Server	Query Cache Use Pct
MySQL Server	Table Cache Hit Pct
MySQL Server	Table Cache Use Pct
MySQL Server	Table Lock Contention Pct

Apache HTTP Server

If Apache HTTP Server is detected on the computer when the omsagent bundle is installed, a performance monitoring provider for Apache HTTP Server will be automatically installed. This provider relies on an Apache module that must be loaded into the Apache HTTP Server in order to access performance data. The module can be loaded with the following command:

sudo /opt/microsoft/apache-cimprov/bin/apache_config.sh -c

To unload the Apache monitoring module, run the following command:

sudo /opt/microsoft/apache-cimprov/bin/apache_config.sh -u

Define performance counters

Once you configure the Log Analytics agent for Linux to send data to Azure Monitor, you must configure the performance counters to collect. Use the procedure in Windows and Linux performance data sources in Azure Monitor with the counters in the following table.

Object Name	Counter Name
Apache HTTP Server	Busy Workers
Apache HTTP Server	Idle Workers
Apache HTTP Server	Pct Busy Workers
Apache HTTP Server	Total Pct CPU
Apache Virtual Host	Errors per Minute - Client
Apache Virtual Host	Errors per Minute - Server
Apache Virtual Host	KB per Request
Apache Virtual Host	Requests KB per Second
Apache Virtual Host	Requests per Second

Next steps

• Collect performance counters from Linux agents.
• Learn about log queries to analyze the data collected from data sources and solutions.