Call PreloadDcdnObjectCaches to prefetch content to L2 cache nodes - Edge Security Acceleration - Alibaba Cloud - Edge Security Acceleration

Operation description

Related operations: Refresh and prefetch operations include the RefreshDcdnObjectCaches refresh operation and the PreloadDcdnObjectCaches prefetch operation.
Request method: POST requests are supported. Parameters are displayed in a form.
Daily URL prefetch quota: By default, each account can commit up to 1,000 URL prefetch nodes per day. If the daily peak bandwidth of your account exceeds 200 Mbit/s, you can apply to increase the daily quota through submit a ticket. Alibaba Cloud will evaluate and configure the quota based on your actual business requirements.
You can commit up to 100 URL prefetch nodes at a time.
Prefetch queue rules: The maximum prefetch queue size for each account is 100,000 URLs. DCDN prefetches URLs in the order they are committed. When the number of unfinished nodes in the prefetch queue reaches 100,000 URLs, Alibaba Cloud DCDN implements a queuing mechanism. This means you can commit the next URL prefetch node only after the first URL in the sorting is prefetched.
Invoke frequency per user: 15 invokes per second.

Precautions

After a prefetch node is committed and successfully executed, the DCDN point of presence (POP) immediately requests resources from the origin server. Therefore, committing a large number of prefetch nodes generates many concurrent download nodes, which causes a sudden increase in back-to-origin bandwidth and requests, and increases the load on the origin server.
The actual execution time from commit to completion of a prefetch node depends on the size of the prefetched files and takes about 5 to 30 minutes. The smaller the average file size, the faster the prefetch speed.
To use a Resource Access Management (RAM) user to perform refresh or prefetch operations, you must first obtain authorization for the Resource Access Management (RAM) user. For more information, see Grant authorization to a Resource Access Management (RAM) user to refresh and prefetch resources.

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Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.
API: The API that you can call to perform the action.
Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.
Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.
- For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.
- For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.
Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.
Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

dcdn:PreloadDcdnObjectCaches

none

*domain

acs:dcdn:*:{#accountId}:domain/{#domainName}

None

Request parameters

Parameter	Type	Required	Description	Example
ObjectPath	string	Yes	The URLs to be prefetched. The format is accelerated domain name/prefetched file. Note Separate multiple URLs with line breaks. The maximum length of a single ObjectPath is 1,024 characters.	http://example.com/examplefile.txt http://example.com/examplefile2.txt
Area	string	No	The prefetch region. Valid values: domestic: the Chinese mainland. overseas: global (excluding the Chinese mainland). If you do not specify this parameter, the default prefetch region is the DCDN acceleration region configured for your domain name. Details are as follows: If the acceleration region of the domain name is the Chinese mainland, the prefetch region is the Chinese mainland. If the acceleration region of the domain name is Global, the prefetch region is global. If the acceleration region of the domain name is Global (excluding the Chinese mainland), the prefetch region is global (excluding the Chinese mainland). Valid values: domestic : The Chinese mainland. overseas : Global (excluding the Chinese mainland).	domestic
L2Preload	boolean	No	Specifies whether to prefetch content directly to L2 nodes. Valid values: true: The node hierarchy for prefetching must include L2 nodes. false: Content is prefetched only to origin-fetching nodes. This is the default value. Origin-fetching nodes can be L2 nodes or L3 nodes.	true
WithHeader	string	No	The custom prefetch headers. Submit the headers in JSON format.	{ "Accept-Encoding": [ "gzip" ] }
QueryHashkey	boolean	No	This parameter is used when specific rules, such as URL rewrite and parameter filtering, are configured. It specifies whether to enable the hash key query mode when executing prefetch tasks. Valid values: false: the default mode. This mode is used when this parameter is not specified. The submitted URL is directly used as the hash key of the prefetched file. true: The actual hash key used for the prefetched URL is queried based on the domain name configuration.	true

Response elements

Element	Type	Description	Example
	object
PreloadTaskId	string	The ID of the prefetch task. Multiple task IDs are separated by commas (,). The returned task IDs are merged based on the following two rules: Prefetch tasks submitted for the same domain name within the same second at the URL granularity are merged into the same RushTaskId. If more than 500 prefetch tasks are submitted for the same domain name within the same second at the URL granularity, every 500 tasks are merged into one RushTaskId.	95248880
RequestId	string	The request ID.	E5BD4B50-7A02-493A-AE0B-97B9024B4135

Examples

Success response

JSON format

{
  "PreloadTaskId": "95248880",
  "RequestId": "E5BD4B50-7A02-493A-AE0B-97B9024B4135"
}

Error codes

HTTP status code	Error code	Error message	Description
400	SingleRequest.OverLimit	A maximum of 1000 URLs are supported for each request.
400	QuotaExceeded.Preload	Your refresh attempts have exceeded the daily limit.	The maximum number of refresh and prefetch requests on the current day has been reached.
400	InvalidObjectPath.Malformed	The specified ObjectPath is invalid.	The ObjectPath parameter is set to an invalid value. Specify a valid value and try again.
400	InvalidExtensiveDomain.ValueNotSupported	The specified ExtensiveDomain is not supported.	Wildcard domain names are not supported.
400	PreloadQueueFull	The warming queue is full; please try again later.	The maximum number of URLs of the objects that are being prefetched has been reached. Try again later.
400	InvalidObjectPath.ExceedsMaximum	The maximum number of urls is exceeded.	The number of submitted URLs exceeds the maximum limit.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.