Log Analytics agent overview

The Azure Log Analytics agent collects telemetry from Windows and Linux virtual machines in any cloud, on-premises machines, and those monitored by System Center Operations Manager and sends it collected data to your Log Analytics workspace in Azure Monitor. The Log Analytics agent also supports insights and other services in Azure Monitor such as VM insights, Microsoft Defender for Cloud, and Azure Automation. This article provides a detailed overview of the agent, system and network requirements, and deployment methods.

Note

You may also see the Log Analytics agent referred to as the Microsoft Monitoring Agent (MMA).

Comparison to Azure diagnostics extension

The Azure diagnostics extension in Azure Monitor can also be used to collect monitoring data from the guest operating system of Azure virtual machines. You may choose to use either or both depending on your requirements. See Overview of the Azure Monitor agents for a detailed comparison of the Azure Monitor agents.

The key differences to consider are:

  • Azure Diagnostics Extension can be used only with Azure virtual machines. The Log Analytics agent can be used with virtual machines in Azure, other clouds, and on-premises.
  • Azure Diagnostics extension sends data to Azure Storage, Azure Monitor Metrics (Windows only) and Event Hubs. The Log Analytics agent sends data to Azure Monitor Logs.
  • The Log Analytics agent is required for solutions, VM insights, and other services such as Microsoft Defender for Cloud.

Costs

There is no cost for Log Analytics agent, but you may incur charges for the data ingested. Check Manage usage and costs with Azure Monitor Logs for detailed information on the pricing for data collected in a Log Analytics workspace.

Supported operating systems

See Supported operating systems for a list of the Windows and Linux operating system versions that are supported by the Log Analytics agent.

Data collected

The following table lists the types of data you can configure a Log Analytics workspace to collect from all connected agents. See What is monitored by Azure Monitor? for a list of insights, solutions, and other solutions that use the Log Analytics agent to collect other kinds of data.

Data Source Description
Windows Event logs Information sent to the Windows event logging system.
Syslog Information sent to the Linux event logging system.
Performance Numerical values measuring performance of different aspects of operating system and workloads.
IIS logs Usage information for IIS web sites running on the guest operating system.
Custom logs Events from text files on both Windows and Linux computers.

Data destinations

The Log Analytics agent sends data to a Log Analytics workspace in Azure Monitor. The Windows agent can be multihomed to send data to multiple workspaces and System Center Operations Manager management groups. The Linux agent can send to only a single destination, either a workspace or management group.

Other services

The agent for Linux and Windows isn't only for connecting to Azure Monitor. Other services such as Microsoft Defender for Cloud and Microsoft Sentinel rely on the agent and its connected Log Analytics workspace. The agent also supports Azure Automation to host the Hybrid Runbook worker role and other services such as Change Tracking, Update Management, and Microsoft Defender for Cloud. For more information about the Hybrid Runbook Worker role, see Azure Automation Hybrid Runbook Worker.

Workspace and management group limitations

See Configure agent to report to an Operations Manager management group for details on connecting an agent to an Operations Manager management group.

  • Windows agents can connect to up to four workspaces, even if they are connected to a System Center Operations Manager management group.
  • The Linux agent does not support multi-homing and can only connect to a single workspace or management group.

Security limitations

Installation options

There are multiple methods to install the Log Analytics agent and connect your machine to Azure Monitor depending on your requirements. The following sections list the possible methods for different types of virtual machine.

Note

It is not supported to clone a machine with the Log Analytics Agent already configured. If the agent has already been associated with a workspace this will not work for 'golden images'.

Azure virtual machine

Windows virtual machine on-premises or in another cloud

Linux virtual machine on-premises or in another cloud

Workspace ID and key

Regardless of the installation method used, you will require the workspace ID and key for the Log Analytics workspace that the agent will connect to. Select the workspace from the Log Analytics workspaces menu in the Azure portal. Then select Agents management in the Settings section.

Workspace details

TLS 1.2 protocol

To ensure the security of data in transit to Azure Monitor logs, we strongly encourage you to configure the agent to use at least Transport Layer Security (TLS) 1.2. Older versions of TLS/Secure Sockets Layer (SSL) have been found to be vulnerable and while they still currently work to allow backwards compatibility, they are not recommended. For additional information, review Sending data securely using TLS 1.2.

Network requirements

The agent for Linux and Windows communicates outbound to the Azure Monitor service over TCP port 443. If the machine connects through a firewall or proxy server to communicate over the Internet, review requirements below to understand the network configuration required. If your IT security policies do not allow computers on the network to connect to the Internet, you can set up a Log Analytics gateway and then configure the agent to connect through the gateway to Azure Monitor. The agent can then receive configuration information and send data collected.

Log Analytics agent communication diagram

The following table lists the proxy and firewall configuration information required for the Linux and Windows agents to communicate with Azure Monitor logs.

Firewall requirements

Agent Resource Ports Direction Bypass HTTPS inspection
*.ods.opinsights.azure.com Port 443 Outbound Yes
*.oms.opinsights.azure.com Port 443 Outbound Yes
*.blob.core.windows.net Port 443 Outbound Yes
*.azure-automation.net Port 443 Outbound Yes

For firewall information required for Azure Government, see Azure Government management.

If you plan to use the Azure Automation Hybrid Runbook Worker to connect to and register with the Automation service to use runbooks or management features in your environment, it must have access to the port number and the URLs described in Configure your network for the Hybrid Runbook Worker.

Proxy configuration

The Windows and Linux agent supports communicating either through a proxy server or Log Analytics gateway to Azure Monitor using the HTTPS protocol. Both anonymous and basic authentication (username/password) are supported. For the Windows agent connected directly to the service, the proxy configuration is specified during installation or after deployment from Control Panel or with PowerShell.

For the Linux agent, the proxy server is specified during installation or after installation by modifying the proxy.conf configuration file. The Linux agent proxy configuration value has the following syntax:

[protocol://][user:password@]proxyhost[:port]

Property Description
Protocol https
user Optional username for proxy authentication
password Optional password for proxy authentication
proxyhost Address or FQDN of the proxy server/Log Analytics gateway
port Optional port number for the proxy server/Log Analytics gateway

For example: https://user01:password@proxy01.contoso.com:30443

Note

If you use special characters such as "@" in your password, you receive a proxy connection error because value is parsed incorrectly. To work around this issue, encode the password in the URL using a tool such as URLDecode.

Next steps

  • Review data sources to understand the data sources available to collect data from your Windows or Linux system.
  • Learn about log queries to analyze the data collected from data sources and solutions.
  • Learn about monitoring solutions that add functionality to Azure Monitor and also collect data into the Log Analytics workspace.