CDH version 6.3.2, YARN version 3.0.0，We use the fair scheduler of yarn Multiple applications were running stfully in a yarn queue. Suddenly, a large number of pending applications appear at a certain time. After checking, it is found that the AM MAX Recources of the queue displayed on the yarn web ui becomes small, as shown in the following figure. As a result, new yarn tasks cannot obtain resources and a large number of pending tasks occur enter image description here enter image description here
The final solution is to change the maxAMShare of the queue to -1 in the dynamic resource pool configuration of yarn, and restore the pool resource after refreshing the pool resource. We want to know why this situation occurs, and why the AM MAX resource of the queue in yarn web ui is limited to such a small resource enter image description here
