Apache HTTP Server Version 2.4
Apache Module mod_lbmethod_bybusyness
| Description: | Pending Request Counting load balancer scheduler algorithm for mod_proxy_balancer |
|---|---|
| Status: | Extension |
| Module Identifier: | lbmethod_bybusyness_module |
| Source File: | mod_lbmethod_bybusyness.c |
| Compatibility: | Split off from mod_proxy_balancer in 2.3 |
Summary
This module does not provide any configuration directives of its own.
It requires the services of mod_proxy_balancer, and
provides the bybusyness load balancing method.
Pending Request Counting Algorithm
Enabled via lbmethod=bybusyness, this scheduler keeps
track of how many requests each worker is currently assigned at present. A new
request is automatically assigned to the worker with the lowest
number of active requests. This is useful in the case of workers
that queue incoming requests independently of Apache, to ensure that
queue length stays even and a request is always given to the worker
most likely to service it the fastest and reduce latency.
In the case of multiple least-busy workers, the statistics (and
weightings) used by the Request Counting method are used to break the
tie. Over time, the distribution of work will come to resemble that
characteristic of byrequests (as implemented
by mod_lbmethod_byrequests).