http_slice module

The module is a filter that splits a request into subrequests, each returning a certain range of response. The filter provides more effective caching of big responses.

This module isn’t built by default; it should be enabled with the ‑‑with‑http_slice_module configuration parameter.

Packages in our repositories have this module built.

Example Configuration

location / {
    slice             1m;
    proxy_cache       cache;
    proxy_cache_key   $uri$is_args$args$slice_range;
    proxy_set_header  Range $slice_range;
    proxy_cache_valid 200 206 1h;
    proxy_pass        http://localhost:8000;
}

In this example, the response is split into 1-megabyte cacheable slices.

Directives

slice

Syntax:

slice size;

Default:

slice 0;

Context:

http, server, location

Sets the size of the slice. The zero value disables splitting responses into slices.

Warning

Note that a too low value may result in excessive memory usage and opening a large number of files.

In order for a subrequest to return the required range, the $slice_range variable should be passed to the proxied server as the “Range” request header field. If caching is enabled, $slice_range should be added to the cache key and caching of responses with 206 status code should be enabled.

Built-in Variables

$slice_range

the current slice range in HTTP byte range format, for example, bytes=0-1048575.