Description of ConcurrencySchedulingPolicy fields - Alibaba Cloud Service Mesh

The ConcurrencySchedulingPolicy CustomResourceDefinition (CRD) is part of the Service Mesh (ASM) traffic scheduling suite. It limits concurrent requests and uses priority-based scheduling to handle excess traffic.

How it works

ConcurrencySchedulingPolicy combines two mechanisms:

Concurrency limiting: max_concurrency sets the maximum number of simultaneous requests. concurrency_limiter configures the concurrency limiter.
Priority-based scheduling: When concurrent requests exceed max_concurrency, scheduler schedules excess requests based on their priorities.

Both mechanisms apply only to requests that match the selectors criteria.

ConcurrencySchedulingPolicySpec

ConcurrencySchedulingPolicySpec is the top-level configuration under the spec field.

Field	Type	Required	Description
`concurrency_scheduler`	ConcurrencyScheduler	Yes	Concurrency limiting and priority-based scheduling configuration.

ConcurrencyScheduler

ConcurrencyScheduler defines the concurrency limit, the limiter algorithm, the priority scheduler, and the request selectors.

Field	Type	Required	Description
`max_concurrency`	int64	Yes	Maximum number of concurrent requests allowed.
`concurrency_limiter`	ConcurrencyLimiterParameters	Yes	Configuration for the concurrency limiter.
`scheduler`	Scheduler	Yes	Configuration for the scheduler that schedules requests based on their priorities when the number of concurrent requests exceeds `max_concurrency`.
`selectors`	[]Selector	Yes	Selectors that determine which requests this policy applies to.