Apache HTTP Server Version 2.4

Apache > HTTP Server > Documentation > Version 2.4 > Modules

# Apache Module mod_lbmethod_bytraffic

Description: | Weighted Traffic Counting load balancer scheduler algorithm for `mod_proxy_balancer`
Status: | Extension
Module Identifier: | lbmethod_bytraffic_module
Source File: | mod_lbmethod_bytraffic.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 `bytraffic` load balancing method.

### Topics

- Weighted Traffic Counting Algorithm

### Directives

This module provides no directives.

### Bugfix checklist

- httpd changelog
- Known issues
- Report a bug

### See also

- `mod_proxy`
- `mod_proxy_balancer`

## Weighted Traffic Counting Algorithm

Enabled via `lbmethod=bytraffic`, the idea behind this scheduler is very similar to the Request Counting method, with the following changes:

lbfactor is how much traffic, in bytes, we want this worker to handle. This is also a normalized value representing their "share" of the amount of work to be done, but instead of simply counting the number of requests, we take into account the amount of traffic this worker has either seen or produced.

If a balancer is configured as follows:

worker | a | b | c
--- | --- | --- | ---
lbfactor | 1 | 2 | 1

Then we mean that we want b to process twice the amount of bytes than a or c should. It does not necessarily mean that b would handle twice as many requests, but it would process twice the I/O. Thus, the size of the request and response are applied to the weighting and selection algorithm.

Note: input and output bytes are weighted the same.