Constraints

Before using VOD, you need to know the following constraints.

Resource Constraints

VOD has constraints on resources such as domain names and watermarks.

**Table 1** Resource constraints
Item	Description	Constraint
Region	New users can use VOD only in CN North-Beijing4, AP-Bangkok, and AP-Singapore.	-
Domain name	Maximum number of self-owned domain names that you can add on the VOD console. NOTE: The system automatically checks all domain names under your name and deletes domain names that have been idle for a long time. For details, see Configuring Domain Names.	5
Pull from URLs	Maximum number of media files that can be pulled at a time	Console: 100 API: 16
URL pull rate	Global maximum rate for pulling audio/video files offline to VOD using the URLs of source audio/video files	1 Gbit/s
Watermarking	Maximum number of watermarks that can be added to a video file at a time	2
Categorization	Maximum number of subcategories can be added to each category	128
Labeling	Maximum number of labels that you can add to a media file	16
Referer validation	Maximum number of domain names that can be added to a referer blacklist or whitelist	100
Media pre-loading	Maximum number of times that one subscriber can pre-load media files in a day	1,000

Function Constraints

**Table 2** Function constraints
Item	Description
Domain name	If a domain name has not been used for more than half a year, an error will be reported when you delete the domain name. In this case, submit a service ticket.
Transcoding	To retain transcoded outputs of different templates, you need to submit a service ticket to apply for this function.
Subtitling	Currently, only single-subtitle files can be uploaded on the console. To upload a multi-subtitle file, see Subtitle Management. The supported formats of single-subtitle and multi-subtitle files are different.

API Constraints

VOD sets a limit on the number of API calls to prevent service interruption caused by repeated API calls in a short period of time.

**Table 3** API request throttling
Category	API	API Calls for a Single Tenant Per Minute	API Calls for All Tenants Per Minute
Media upload	Uploading media files to VOD Obtaining upload authorization Confirming media upload Replicating media files in OBS to VOD	1,500	12,000
Media upload	Pulling media files from URLs Verifying the upload	100	1,000
Media processing	Updating a video Media processing Canceling a media asset transcoding task Extracting audio Canceling an audio extraction task Creating a media asset review task Setting a thumbnail	100	1,000
Media management	Deleting media files Publishing media files Canceling media publish Modifying file attributes	100	1,000
	Querying file information	1,500	24,000
	Querying file details Querying media files	1,500	12,000
Media pre-loading	CDN pre-loading Querying pre-loading results	100	1,000
Media category	Creating a media category Modifying a media category Deleting a media category Querying media categories	100	1,000
Key query	Key query	1,500	12,000
Statistical analysis	Querying CDN statistics Querying origin server statistics Querying the most requested content Querying playback logs of a domain name Querying daily playback statistics of a media asset	100	1,000
Watermark template management	Creating a watermark template Modifying a watermark template Querying watermark templates Deleting a watermark template Confirming watermark image upload	100	1,000
Subtitle management	Managing subtitles	100	1,000
Transcoding template management	Creating a custom transcoding template Querying transcoding templates Updating a transcoding template Deleting a custom template	100	1,000
Transcoding template set management	Creating a transcoding template group set Modifying a transcoding template group set Querying custom template group sets Deleting a transcoding template group set	100	1,000