Metadata API Developer Guide
jNote: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.
Does a Retrieve Job Have a Status of Pending?
If you initiate several concurrent retrieve operations for a single
org, Metadata API automatically puts some of those jobs in a queue, if that becomes necessary for
service protection. If a retrieve job has a status of Pending, it’s
in the queue. When one of the active retrieve jobs completes, Metadata API takes a pending job
from the queue and activates it. If a retrieve job has a status of
InProgress, it’s active. The process repeats until the job queue is
cleared.
For more information, see "Metadata Limits" in the Salesforce Developer Limits and Allocations Quick Reference.