Apache HTTP Server Version 2.4
Apache HTTP Server Version 2.4
| Description: | Dynamic health check of Balancer members (workers) for
mod_proxy |
|---|---|
| Status: | Extension |
| Module Identifier: | proxy_hcheck_module |
| Source File: | mod_proxy_hcheck.c |
| Compatibility: | Available in Apache 2.4.21 and later |
This module provides for dynamic health checking of balancer members (workers). This can be enabled on a worker-by-worker basis. The health check is done independently of the actual reverse proxy requests.
This module requires the service of mod_watchdog.
The health check mechanism is enabled via the use of additional
BalancerMember parameters, which are configured
in the standard way via ProxyPass:
A new BalancerMember status state (flag)
is defined via this module: "C".
When the worker is taken offline due to failures as determined by the health
check module, this flag is set, and can be seen (and modified) via the
balancer-manager.
| Parameter | Default | Description | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| hcmethod | None | No dynamic health check performed. Choices are:
| |||||||||||||||||||||||||||||||||
| hcpasses | 1 | Number of successful health check tests before worker is re-enabled | |||||||||||||||||||||||||||||||||
| hcfails | 1 | Number of failed health check tests before worker is disabled | |||||||||||||||||||||||||||||||||
| hcinterval | 30 | Period of health checks in seconds (e.g. performed every 30 seconds) | |||||||||||||||||||||||||||||||||
| hcuri | Additional URI to be appended to the worker URL for the health check. | ||||||||||||||||||||||||||||||||||
| hctemplate | Name of template, created via ProxyHCTemplate,
to use for setting health check parameters for this worker | ||||||||||||||||||||||||||||||||||
| hcexpr | Name of expression, created via ProxyHCExpr,
used to check response headers for health.If not used, 2xx thru 3xx status codes imply success | ||||||||||||||||||||||||||||||||||
OPTIONS11, HEAD11 and GET11 are
available in 2.4.55 and above.
