9.4.3 Proxy Tuning Directives

Global directive: BackendStats bool

Whether to enable backend statistics collection. Backend statistics consists of the following values:

1. Total number of requests processed by this backend.
2. Average time per request.
3. Standard deviation of the average time per request.

If enabled, these values are made available via poundctl (see poundctl list) and telemetry output (see Metrics).

Global directive: Balancer algo

Sets the request balancing algorithm to use. Allowed values for algo are:

random

Use weighted random balancing algorithm.

iwrr

Use interleaved weighted round robin balancing.

See Balancer, for a detailed discussion of these algorithms.

The Balancer statement in global scope applies to all Service definitions in the file that don’t contain Balancer definitions of their own.

Global directive: HeaderOption opt ...

Sets default header addition options. One or more arguments are allowed, each being one of:

off

Disable additional headers.

forwarded

Add X-For-warded-For, X-Forwarded-Proto, and X-Forwarded-Port headers.

ssl

Pass information about SSL certificates in a set of X-SSL-* headers. This will add the following headers:

X-SSL-Cipher

SSL version followed by a slash and active cipher algorithm.

X-SSL-Certificate

The full client certificate (multi-line).

X-SSL-Issuer

Information about the certificate issuer (CA).

X-SSL-Subject

Information about the certificate owner.

X-SSL-notAfter

End of validity date for the certificate.

X-SSL-notBefore

Start of validity date for the certificate.

X-SSL-serial

Certificate serial number (in decimal).

The default is:

HeaderOption forwarded ssl

This setting can be overridden for a particular listener using the HeadOption within it.