
icm/HTTP/server_cache_<xx>
This parameter is used to determine the URI prefix and the destination directory for the internal ICM HTTP server cache.

Meaning
This stands for the number of the entry being specified. Several assignments between the URL prefix and the cache directory, numbered in ascending order from 0, can be specified. (However, it is recommended that only one assignment be used).
All HTTP URIs that begin with this character string are channeled through the
ICM Server Cache. This is to check whether a suitable HTTP response to the request already exists in the ICM cache. If this is the case, the response can be sent directly (in other words, without passing through the SAP application server) from the cache to the HTTP client (browser).Complete file system path details for the directory (in the local file system of the relevant application server) in which the data stored in the cache can be saved.

icm/HTTP/server_cache_0= PREFIX=/foo/bar, CACHEDIR=/usr/cachedir
This channels via the cache in the directory ‘/usr/cachedir’ all HTTP requests whose URI path begins with ‘/foo/bar’.
Default
icm/HTTP/server_cache_0 = PREFIX=/, CACHEDIR=$(DIR_DATA)/cache
The presetting dictates that all HTTP requests (prefix "/") are channeled via the cache located in the standard ‘DATA’ directory on the application server.