***
title: "PollingJobQueueStrategy"
generated: true
---------------
This class allows easier implementation of [JobQueueStrategy](/current/core/reference/typescript-api/job-queue/job-queue-strategy#jobqueuestrategy) in a polling style.
Instead of providing [JobQueueStrategy](/current/core/reference/typescript-api/job-queue/job-queue-strategy#jobqueuestrategy) `start()` you should provide a `next` method.
This class should be extended by any strategy which does not support a push-based system
to notify on new jobs. It is used by the [SqlJobQueueStrategy](/current/core/reference/typescript-api/job-queue/sql-job-queue-strategy#sqljobqueuestrategy) and [InMemoryJobQueueStrategy](/current/core/reference/typescript-api/job-queue/in-memory-job-queue-strategy#inmemoryjobqueuestrategy).
```ts title="Signature"
class PollingJobQueueStrategy extends InjectableJobQueueStrategy {
public concurrency: number | ((queueName: string) => number);
public pollInterval: number | ((queueName: string) => number);
public setRetries: (queueName: string, job: Job) => number;
public backOffStrategy?: BackoffStrategy;
public gracefulShutdownTimeout: number;
protected activeQueues = new QueueNameProcessStorage>();
constructor(config?: PollingJobQueueStrategyConfig)
constructor(concurrency?: number, pollInterval?: number)
constructor(concurrencyOrConfig?: number | PollingJobQueueStrategyConfig, maybePollInterval?: number)
start(queueName: string, process: (job: Job) => Promise) => ;
stop(queueName: string, process: (job: Job) => Promise) => ;
cancelJob(jobId: ID) => Promise;
next(queueName: string) => Promise;
update(job: Job) => Promise;
findOne(id: ID) => Promise;
}
```
* Extends: InjectableJobQueueStrategy
### concurrency
\
number)`} />
### pollInterval
\ number)`} />
### setRetries
\Job) => number`} />
### backOffStrategy
\BackoffStrategy`} />
### gracefulShutdownTimeout
\
### activeQueues
\
### start
\Job) => Promise) => `} />
### stop
\Job) => Promise) => `} />
### cancelJob
\ID) => Promise<Job | undefined>`} />
### next
\ Promise<Job | undefined>`} />
Should return the next job in the given queue. The implementation is
responsible for returning the correct job according to the time of
creation.
### update
\Job) => Promise`} />
Update the job details in the store.
### findOne
\ID) => Promise<Job | undefined>`} />
Returns a job by its id.