Help Center/ MapReduce Service/ Component Operation Guide (LTS)/ Using YARN/ Common Issues About Yarn/ An Application Fails to Resume Execution After Being Moved from the Lost_and_found Queue to Another Queue
Updated on 2025-08-22 GMT+08:00

An Application Fails to Resume Execution After Being Moved from the Lost_and_found Queue to Another Queue

Question

When a queue containing running applications is deleted, those applications are automatically moved to the Lost_and_found queue. When these applications are moved back to a properly functioning queue, some tasks remain suspended and fail to resume execution as expected.

Answer

If an application does not specify a label expression, any newly allocated containers or resources will inherit the default label expression of the queue to which the application is assigned. If no default label expression is configured for the queue, the system assigns the label expression default label to the queue.

When application app1 is submitted to queue Q1, any newly allocated containers or resources inherit the default label expression label1 of queue Q1. If queue Q1 is deleted while application app1 is running, application app1 is moved to the lost_and_found queue. Since the lost_and_found queue does not have a defined label expression, its label expression defaults to default label. Consequently, any newly allocated containers or resources for application app1 will also inherit the default label label expression. When application app1 is moved back to a properly functioning queue (for example, Q2), its execution depends on the label expressions supported by that queue. If queue Q2 supports all label expressions used by application app1 (including label1 and default label), the application can continue running normally until completion. However, if queue Q2 supports only a subset of the label expressions (for example, only default label), then tasks within application app1 that request resources using unsupported label expression (for example, label1) will fail to acquire resources. As a result, those tasks become suspended and cannot proceed.

Therefore, when moving an application from the lost_and_found queue to a properly functioning queue, ensure that the target queue supports all label expressions used by the application.

It is recommended that you do not delete any queue that contains running applications.