DataHub:Limits

Limitations

Description

Value range

Active shards

The maximum number of active shards in each topic.

(0,256]

Total shards

The maximum number of total shards in each topic.

(0,512]

HTTP body size

The maximum size of an HTTP request body.

4 MB

String length

The maximum length of a single string field.

2 MB

Merge and split frequency limits

Each newly created shard cannot be merged or split for a certain period.

5s

Queries per second (QPS)

The maximum write QPS for each shard. A batch write to a shard is counted as one query, regardless of the number of records.

2,000

Throughput Limit

The maximum write throughput per second for each shard.

5 MB/s

Project limits

The maximum number of projects per Alibaba Cloud account.

50

Topic limits

The maximum number of topics that can be created in each project. If you have other requirements, contact an administrator.

500

Topic lifecycle limitations

The maximum data retention period for each topic. Unit: days.

[1,7]

Records per batch write

The maximum number of records in a single batch write.

10,000

Subscription limits

The maximum number of tracking tasks per topic.

1,000

Topics per Kafka group

The maximum number of topics to which a Kafka group can subscribe.

50

Term

Description

Length limit

Value

Project

The name of a project.

[3,32]

The name must start with a letter and can contain only letters, digits, and underscores (_). The name is case-insensitive.

Topic

The name of a topic.

[1,128]

The name must start with a letter and can contain only letters, digits, and underscores (_). The name is case-insensitive.

Field

The name of a field.

[1,128]

The name must start with a letter and can contain only letters, digits, and underscores (_). The name is case-insensitive. The name system_time is not allowed.

SubscriptionId

Set the subscription ID manually

[4,40]

The ID must start with a lowercase letter and can contain only lowercase letters, digits, and underscores (_). The ID is case-sensitive.