The Data Integration Service uses persisted queues to store deployed mapping jobs and workflow mapping tasks. Persisted queuing protects against data loss if a node shuts down unexpectedly.

When you deploy a mapping job or workflow mapping task, the Data Integration Service moves these jobs directly to the persisted queue for that node. The job state is "Queued" in the Administrator tool contents panel. When resources are available, the Data Integration Service starts running the job.

Every node in a grid has one queue. Therefore, if the Data Integration Service shuts down unexpectedly, the queue does not fail over when the Data Integration Service fails over. The queue remains on the Data Integration Service machine, and the Data Integration Service resumes processing the queue when you restart it.

By default, each queue can hold 10,000 jobs at a time. When the queue is full, the Data Integration Service rejects job requests and marks them as failed. When the Data Integration Service starts running jobs in the queue, you can deploy additional jobs.

Persisted queuing is available for certain types of jobs, but not all. When you run a job that cannot be queued, the Data Integration Service immediately starts running the job. If there are not enough resources available, the job fails.

The following job types cannot be queued:

Data previews
Profiling jobs
REST queries
SQL queries
Web service requests