HAProxy Enterprise Documentation 1.8r2

Active Health Checks

An active health check attempts to connect to a server or send it an HTTP request at a regular interval. If the connection cannot be established or the HTTP request fails, the health checks fails.

If the number of consecutive failed checks meets the failure threshold, the server is taken out of rotation. Health checks continue while the server is down, however. If the server resumes service and responds successfully to the health checks, and if the number of consecutive successful responses meets the success threshold, the server is restored to rotation.

TCP Health Checks

Use a TCP health check to establish a connection to a backend server.

HTTP Health Checks

Send an HTTP request to a backend server.

Health Check Interval

You can change how often health checks are sent.

Health Check Threshold

You can change thresholds that determine whether a server is up or down.

Connection Parameters

Define connection protocols, IP address, and other parameters.

Expected Status or String

Define the return string or status that indicates success.

Logging Comments on Failure

Define comments to be logged upon check failure.


Set and unset custom variables for use in HTTP and TCP checks.

Next up

TCP Health Checks