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Sep 01, 2021


Did you test it with larger environments? It's working well with small (20-30 esx nodes) deployments, but we have a larger one with ~400 hosts and 7000VM. It hangs after a while during these tasks: Getting Numa Stats for VMs on HostSystem.

Sep 08, 2021

Hi Janos,

We are investigating this. Can you please open a bug on the Flings site and add the error logs from the NUMA Observer logs directory to the bug?


Sep 02, 2021

Hi Janos,

Thanks for your question. We'll look into this and get back shortly.


Aug 19, 2021

How do I troubleshoot? Trying to connect to vCenter, I get 'Backend Error, Please check logs.' In the java console log I see Starting connection thread for VC, then CONNECTION ESTABLISHMENT - END, then initialize END, Total Task Exceptions: 1

Aug 19, 2021

Hi Patrick,

The issue is most likely due to NUMA Observer trying to verify the self-signed certificate presented by the VC (internally deployed VC/ESX use self-signed certs).

When connecting to internal VC/ESX instances from NUMA Observer, please use the "-sslNoVerify" commandline argument.

Please use "java -jar NUMA-Observer-<version>.jar -h", for instructions.



Aug 20, 2021

The vCenter has a public SSL cert - in any event, I tried with the -sslNoVerify flag and receive the same error.

The error log is full of 'Could not initialize class com.vmware.connections.GenericConnect' errors.

I haven't had to install Java in probably 10 years at this point. I looked at the Oracle stuff and saw all of the licensing restrictions and didn't want to mess with it. I installed openJDK 16.0.2. Could that be my problem? Incompatible Java versions? The requirements say that 'Java 8' is required, but when I look on Oracle's site, Java 8 brings me to an installer for Java SE 16.0.2. So I feel like the versioning is correctl.

Aug 24, 2021
Oct 05, 2021

I have used the latest Java by downloading the above link, I am getting same error "Backend Error, Please check logs."
could you please share how to do the configuration changes to the downloaded Flings

Oct 13, 2021

Hi Viswanadharaju,

can you please confirm if you VC has public SSL cert and whether you have already tried the -sslNoVerify flag?


Oct 18, 2021

Could you please share the step by step document to update the suggested changes.