To Reproduce Steps to reproduce the behavior:

1. Perform a minor update to RHOSP 17.1.9
2. Wait for a while
3. The memory usage of neutron-server suddenly starts to increase linearly
4. The memory usage increases unlimitedly and cause OOM

Expected behavior

• neutron-server doesn't have memory leak

Bug impact

• High memory usage makes the controller node unstable, and finally it reaches to OOM

Known workaround

• Nothing