Get value from cache

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APPLIES TO: All API Management tiers

Use the cache-lookup-value policy to perform cache lookup by key and return a cached value. The key can have an arbitrary string value and is typically provided using a policy expression.

Note

This policy must have a corresponding Store value in cache policy.

Important

Built-in cache is volatile and is shared by all units in the same region in the same API Management service.

Note

Set a policy's elements and child elements in the order provided in the policy statement. Learn more about how to set or edit API Management policies.

Policy statement

<cache-lookup-value key="cache key value"
    default-value="value to use if cache lookup resulted in a miss"
    variable-name="name of a variable looked up value is assigned to"
    caching-type="prefer-external | external | internal" />

Attributes

Attribute Description Required Default
caching-type Choose between the following values of the attribute:
- internal to use the built-in API Management cache,
- external to use the external cache as described in Use an external Azure Cache for Redis in Azure API Management,
- prefer-external to use external cache if configured or internal cache otherwise.

Policy expressions aren't allowed.		 No prefer-external
default-value A value that will be assigned to the variable if the cache key lookup resulted in a miss. If this attribute is not specified, null is assigned. Policy expressions are allowed. No null
key Cache key value to use in the lookup. Policy expressions are allowed. Yes N/A
variable-name Name of the context variable the looked up value will be assigned to, if lookup is successful. If lookup results in a miss, the variable will not be set. Policy expressions aren't allowed. Yes N/A

Usage

Example

<cache-lookup-value
    key="@("userprofile-" + context.Variables["enduserid"])"
    variable-name="userprofile" />

For more information and examples of this policy, see Custom caching in Azure API Management.

Next steps

For more information about working with policies, see: