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Configures how the cached values should be purged from the cache.

<InvalidateCache async="false" continueOnError="false" enabled="true" name="policy-name">
    <DisplayName>Policy Name</DisplayName>
    <FaultRules>rules_for_fault_handling</FaultRules>
    <Properties>property_elements</Properties>
    <CacheKey>
        <Prefix>prefix_string</Prefix>
        <KeyFragment ref="variable_reference"/>
        <KeyFragment>fragment_string</KeyFragment>
    </CacheKey>
    <CacheResource>cache_to_use</CacheResource>
    <Scope>scope_enumeration</Scope>
    <CacheContext>
        <APIProxyName>application_that_added_the_entry</APIProxyName>
        <ProxyName>proxy_for_which_data_was_cached</ProxyName>
        <TargetName>endpoint_for_which_data_was_cached</TargetName>
    </CacheContext>
    <PurgeChildEntries>true_to_purge_all_child_entries</PurgeChildEntries>
</InvalidateCache>

Your organization comes with a default cache. For more about the underlying data store, see Why Use a Cache?. For more about configuring caches, see Manage caches for an environment.

InvalidateCache children

Element Default Description
DisplayName   Captures the policy’s function with a short, intuitive name.
FaultRules   Configures fault handling for the policy. For more on fault handling, see Fault handling or Policy attachment and enforcement.
Properties   Specifies property/value pairs that configure specific behavior.
CacheKey   Configures a unique pointer to a piece of data stored in the cache.
CacheResource   Specifies the cache where messages should be stored. A default cache is available.
Scope Exclusive Enumeration used to construct a prefix for a cache key when a Prefix element is not provided in the CacheKey element.
CacheContext   Specifies how to construct a cache key when a Prefix element value is not specified, or to clear cache entries added by another API proxy.
PurgeChildEntries   true to purge child cache entries when invalidating the cache. Default is false.

InvalidateCache attributes

Attribute Type Default Required Description
async boolean false No

true to specify that the policy should be run in a thread pool different than the pool servicing the request/response flow. Default is false.

This setting is only used for for internal optimization. Contact Apigee support at the Support Portal for more information.

continueOnError boolean false No

true to specify that flow execution should continue on a failure. Default is false.

Most policies are expected to return an error when a failure occurs (for example, when a Quota is exceeded).

name string   No

Specifies the name of the policy, which is referenced in Step elements to attach the policy to a flow. Characters you can use in the name are restricted to: A-Z0-9._\-$ %.


CacheKey element

Configures a unique pointer to a piece of data stored in the cache.

<CacheKey>
    <Prefix>string</Prefix>
    <KeyFragment ref="variable_name" />
    <KeyFragment>literal_string</KeyFragment>
</CacheKey>

CacheKey constructs the name of each piece of data stored in the cache. The cache key you define in the PopulateCache policy is the name that you use in the LookupCache policy to get the specific entry that you need from the cache.

At runtime, KeyFragment values are prepended with either the Scope element value or Prefix value. For example, the following results in a cache key of UserToken__apiAccessToken__<value_of_client_id>:

<CacheKey>
    <Prefix>UserToken</Prefix>
    <KeyFragment>apiAccessToken</KeyFragment>
    <KeyFragment ref="request.queryparam.client_id" />
</CacheKey>

You use the CacheKey element in conjunction with Prefix and Scope. For more information, see Working with cache keys.

CacheKey children

Element Default Description
Prefix   Specifies a value to use as a cache key prefix.
KeyFragment   Specifies a value that should be included in the cache key, creating a namespace for matching requests to cached responses.

Prefix element

Specifies a value to use as a cache key prefix.

<Prefix>prefix_string</Prefix>

Use this value instead of Scope when you want to specify your own value rather than a Scope -enumerated value. If defined, Prefix prepends the cache key value for entries written to the cache. A Prefix element value overrides a Scope element value.

You use the Prefix element in conjunction with CacheKey and Scope. For more information, see Working with cache keys.


KeyFragment element

Specifies a value that should be included in the cache key, creating a namespace for matching requests to cached responses.

<KeyFragment ref="variable_name"/>
<KeyFragment>literal_string</KeyFragment>

This can be a key (a static name that you provide) or a value (a dynamic entry set by referencing a variable). All specified fragments combined (plus the prefix) are concatenated to create the CacheKey.

<KeyFragment>apiAccessToken</KeyFragment>
<KeyFragment ref="request.queryparam.client_id" />

You use the KeyFragment element in conjunction with Prefix and Scope. For more information, see Working with cache keys.

KeyFragment attributes

Attribute Type Default Required Description
ref string   No

The variable from which to get the value. Should not be used if this element contains a literal value.


CacheResource element

Specifies the cache where messages should be stored. A default cache is available.

<CacheResource>cache_to_use</CacheResource>

For more about configuring caches, see Manage caches for an environment.


Scope element

Enumeration used to construct a prefix for a cache key when a Prefix element is not provided in the CacheKey element.

<Scope>scope_enumeration</Scope>

The Scope setting determines a cache key that is prepended according to the Scope value. For example, a cache key would take the following form when scope is set to Exclusive : orgName__envName__apiProxyName__deployedRevisionNumber__proxy|TargetName__ [ serializedCacheKey ].

If a Prefix element is present in CacheKey, it supercedes a Scope element value. Valid values include the enumerations below.

You use the Scope element in conjunction with CacheKey and Prefix. For more information, see Working with cache keys.

Scope values

Global

CacheKey is shared across all API proxies deployed in the environment. Cache key is prepended in the form  orgName __ envName __.

If you define a CacheKey entry with the KeyFragment apiAccessToken and a Global scope, each entry is stored as orgName__envName__apiAccessToken, followed by the serialized value of the access token. For an API proxy deployed in an environment called 'test' in an organization called 'apifactory', access tokens would be stored under the following CacheKey: apifactory__test__apiAccessToken.

APIProxy

API proxy name is used as the prefix.

Cache key is prepended in the form orgName__envName__apiProxyName.

Proxy

ProxyEndpoint configuration is used as the prefix.

Cache key is prepended in the form orgName__envName__apiProxyName__deployedRevisionNumber__proxyEndpointName .

Target

TargetEndpoint configuration is used as the prefix.

Cache key prepended in the form orgName__envName__apiProxyName__deployedRevisionNumber__targetEndpointName .

Exclusive

Default. This is the most specific, and therefore presents minimal risk of namespace collisions within a given cache.

Prefix is one of two forms:

  • If the policy is attached to the ProxyEndpoint flow, prefix is of the form ApiProxyName_ProxyEndpointName.
  • If the policy is attached at TargetEndpoint, prefix is of the form ApiProxyName_TargetName.

Cache key prepended in the form orgName__envName__apiProxyName__deployedRevisionNumber__proxyNameITargetName

For example, the full string might look like this:

apifactory__test__weatherapi__16__default__apiAccessToken
.

CacheContext element

Specifies how to construct a cache key when a Prefix element value is not specified, or to clear cache entries added by another API proxy.

<CacheContext>
  <ApplicationName ref="">{0,1}</ApplicationName>
  <TargetName ref="">{0,1}</TargetName>
  <ProxyName ref="">{0,1}</ProxyName>
</CacheContext>

Used to construct the CacheKey. Values for APIProxyName, ProxyName and TargetName are mandatory in the following cases: When a CacheKey Prefix (that is, a custom prefix) is not used To clear cache entries added by another API proxy.

CacheContext children

Element Default Description
APIProxyName   Specifies the name of the application that added the cache entry.
ProxyName   Specifies the name of the proxy for which the data was cached.
TargetName   Specifies the name of the target endpoint for which the data was cached.

APIProxyName element

Specifies the name of the application that added the cache entry.

<APIProxyName>application_that_added_the_entry</APIProxyName>

APIProxyName attributes

Attribute Type Default Required Description
ref string   No

 


TargetName element

Specifies the name of the target endpoint for which the data was cached.

<TargetName>endpoint_for_which_data_was_cached</TargetName>

TargetName attributes

Attribute Type Default Required Description
ref string   No

 


ProxyName element

Specifies the name of the proxy for which the data was cached.

<ProxyName>proxy_for_which_data_was_cached</ProxyName>

ProxyName Attributes

Attribute Type Default Required Description
ref string   No

 


PurgeChildEntries element

true to purge child cache entries when invalidating the cache. Default is false .

<PurgeChildEntries>true_to_purge_child_entries</PurgeChildEntries>

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