The number of host connections exceeds the threshold, and VMs are repeatedly HA.

Latest reply: Oct 18, 2019 03:07:44 907 2 7 0

[Fault type]

HA occurs repeatedly on the VM.


[Key words]

The number of VM HA and connection trace tables exceeds the threshold.


[Applicable version]

FusionCompute R5 or later.


[Diagnostic]

The number of host connections exceeds the threshold and VMs are repeatedly HA.

 

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[Solution]

1. Repeated VM HA is caused by frequent network requests from a VM on the host. As a result, the number of host connections exceeds the threshold, the communication between the host and VRM is interrupted intermittently and the VRM cannot obtain the VM status on the host, so the VM HA is triggered.

However, the storage plane obtains the VM running status and waits for the VRM to refresh the VM status. If the network pressure decreases, the communication between the host and VRM recovers and the HA is canceled. If the network is interrupted again due to pressure, VM HA is also triggered. This is a fake HA, which does not affect VM usage, but network pressure affects management services.


2. If the number of host connections exceeds the threshold, it may occur in public cloud scenarios (attacks or services are abnormal) or some customers require high network bandwidth. Therefore, the following measures are taken to avoid this problem:


u  Check whether the user network is attacked.

u  Check the network requirements of customers' services and migrate VMs to hosts with small network services.

u  Distribute heavy-traffic VMs and management VM VRMs to different hosts (non-management nodes).

u  Limit the bandwidth of elastic IP addresses and limit the bandwidth of Layer 2 networks.

 

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guanjf
guanjf Created Mar 31, 2019 15:53:51
it's wonderful  
piaopiaoran
Created 6 days ago Helpful(0) Helpful(0)

great
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