# Removed Cached Attribute

## Contents
Overview Configuration

## Overview
The Remove Cached Attribute filter allows you to delete a message attribute value that has been stored in a cache. Each cache is essentially a map of name-value pairs, where each value is keyed on a particular message attribute. For example, it is possible to store a cache of request messages according to their message ID. In this case the message's `id` attribute would be the key into the cache, which would store the value of the request message's `content.body` message attribute. In this example, the Remove Cached Attribute filter can be used to remove a particular entry from the cache based on the run-time value of a particular message attribute. By specifying the `id` message attribute to remove, the Enterprise Gateway will look up the cache based on the value of the `id` message attribute. When it finds a matching message ID in the cache, it will remove the corresponding entry from the cache. The example described above may be useful in cases where a request message may need to be cached and stored until the request has been fully processed and a response returned to the client. For example, if the request must be routed on to a back-end Web Service, but that Web Service is temporarily unavailable, it may be possible to configure the circuit to re-send the cached request instead of forcing the client to retry. For more information on how to configure a "caching circuit", please refer to the Global Caches tutorial.
## Configuration
Name: Enter a name for this filter here. Select Cache to Use: The list of currently configured caches will be displayed in the tree. Select the name of the cache that contains the cached values that have been keyed according to the message attribute specified below. Global caches (both local and distributed) can be added from the Caches top level node in the tree view of the Policy Studio. Attribute Key: Enter the message attribute that is used as the key into the cache in this field. At run-time, the Enterprise Gateway will populate the value of this message attribute, which will then be used to lookup the cache selected in the table above. If a match is found in the cache, the corresponding entry will be deleted from the cache.