NAME

vmod_h2 - Module to control the built-in HTTP2 transport

SYNOPSIS

import h2 [as name] [from "path"]
BOOL is()
DURATION rapid_reset([DURATION threshold])
INT rapid_reset_limit([INT number])
DURATION rapid_reset_period([DURATION duration])
REAL rapid_reset_budget()

DESCRIPTION

This VMOD contains functions to control the HTTP2 transport built into Varnish-Cache.

BOOL is()

Restricted to: client.

Returns true when called on a session handled by the built-in HTTP2 transport.

DURATION rapid_reset([DURATION threshold])

Restricted to: client.

Get and optionally set the h2_rapid_reset parameter (See varnishd(1)) for this HTTP2 session only.

Returns -1 when used outside the HTTP2 transport. Otherwise returns the previous value.

If the call leads to a change in the rate limit parameters, the current budget as retuned by h2.rapid_reset_budget() is reset.

INT rapid_reset_limit([INT number])

Restricted to: client.

Get and optionally set the h2_rapid_reset_limit parameter (See varnishd(1)) for this HTTP2 session only.

Returns -1 when used outside the HTTP2 transport. Otherwise returns the previous value.

If the call leads to a change in the rate limit parameters, the current budget as retuned by h2.rapid_reset_budget() is reset.

DURATION rapid_reset_period([DURATION duration])

Restricted to: client.

Get and optionally set the h2_rapid_reset_period parameter (See varnishd(1)) for this HTTP2 session only.

Returns -1 when used outside the HTTP2 transport. Otherwise returns the previous value.

If the call leads to a change in the rate limit parameters, the current budget as retuned by h2.rapid_reset_budget() is reset.

REAL rapid_reset_budget()

Restricted to: client.

Return how many RST frames classified as "rapid" the client is still allowed to send before the session is going to be closed.

COPYRIGHT

Copyright 2023 UPLEX - Nils Goroll Systemoptimierung
All rights reserved.
Author: Nils Goroll <nils.goroll@uplex.de>
SPDX-License-Identifier: BSD-2-Clause
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright


   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright


   notice, this list of conditions and the following disclaimer in the


   documentation and/or other materials provided with the distribution.
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