Purpose: Indicates degradation in Edge performance
Impact: Decreased Edge performance
Environment
VMware NSX-T Data Center
Edge Form factors:
Bare Metal Edge
VM Edge
Cause
Reason for low Flow Cache hit rate:
Unsupported traffic type
Short lived traffic
Number of traffic flows / streams is greater than the size of Flow cache.
Resolution
Steps to Resolve For 3.2.0 and higher
Recommended Action:
The Micro flow cache stats can be obtained using 'get dataplane flow-cache stats' Edge node CLI.
Snippet of sample output for get dataplane flow-cache stats with Micro flow cache stats
If the alarm persists for a long period of time or happens often move to an Edge with larger form factor. To increase form factor follow the steps to Redeploy NSX Edge. In case of VMC follow the steps to Scaleup SDDC. Note: This resolution does not apply for a Bare metal edge.