vCenter and PSC HA 6 with high latency

[tswiss]

Hi guys,

we have around 10 locations with each a few hosts.

3 of those are big hubs located in the regions North A., Europe and Asia.

Currently almost all sites have their own vCenter (5.x - 6).

I'd like to consolidate the vCenters but I have read that the PSC are very sensitive in terms of latency.

I assume 100ms is the maximum, same as for long-distance vMotion!?

Between our 3 hubs we have around 200-250ms latency.

Latency within a region is around 20-90ms.

So now I'm unsure if this will work:

Each hub would have 1 vCenter (or maybe 2 with failover cluster, and ext. SQL DB) managing all their clusters within the region.

Each hub would have 2 PSC Appliances, all in the same sso domain and same site.

I was hoping to get some good input here on how you would tackle that.

Many thanks in advance!

[vmEck · Accepted solution]

You're spot on with your 100ms max latency between PSCs. BTW, max latency for long distance vMotion is 150ms RTT. These are not hard technical limits but what we are comfortable supporting based on our own testing. Would things technically work with higher latencies? Probably. But don't put yourself in a risky position that may prevent you from getting support if there is an issue.

Having said that, what many large customers are doing today is consolidating down to one SSO domain per region. It would be great if we could get down to one global SSO domain, but today, in vSphere 6.0, we would really advise not going over 100ms. The higher the latency between PSCs, the higher the risk of conflicting changes within the SSO domain. Also, from a UI performance perspective, if you are managing multiple vCenters via Enhanced Linked Mode, it is going to get slower and slower as that latency increases.

We're definitely collecting feedback from customers and we would like to allow our customers to architect their SSO domains as they see fit. But today we have these guidelines we need to work within. Hope this helps!

[tswiss]

Thanks for the good explaination. We will move in that direction then.

As pretty much everything is getting more and more complex due to an increasing nr. of additonal features simplicity should still be on the list.

I would say VMware does a good job but of course everybody has room for improvement.

Looking at the PSC the HA feature could use some simplicity (no more manual HA scripts downloading, uploading, and excecuting plenty of commands.)

Similar the vCenters, instead of the windows failover clustering I'm positive to see some independent, in-app solution in the future.

Maybe it will also be possible to peer vCenters of different regions / sso domains in the future to make use of some features.

For example we would like to use a global content library where higher latency should not be a showstopper.

Looking forward to the next versions, thanks again!