scaleout on vsphere 6.5 environment - windows server 2012 r2 vms

[asavagemonster]

Good morning,

We are attempting to move our scaleout physical infrastructure to our virtual infrastructure.. We've deployed a couple VMs with the software installed and are finding that they cannot communicate with the physical hosts over the dedicated multicast vlan configured for the physicals and vms.

I've enabled multicast snooping on the distributed vSwitch but the systems still cannot discover the physicals through server manager.

Apparently all of the physical hosts are plugged into the same switch for the multicast vlan (which i just learned).. if multicast wasnt setup properly on the switch i assume the fact that the physicals being all plugged into the same switch would negate that..

My ESX hosts are plugged into different switches than the physical scaleout servers..

What are the specific settings on the Cisco 5k switches that we should configure to allow the physicals and VMs to communicate with eachother over the same VLAN for multicast?

Please let me know if you have any questions.

Thank you,

Adam Savage

 

[markw]

So, just to verify, I assume the two new VM systems are able to discover each other, correct? If not, I'd recommend getting those two talking first (it's usually a Windows firewall issue in the guest causing problems there).

In any case, we don't have specific expertise in Cisco hardware, so we won't be able to offer guidance about how to enable multicast there. An alternative to relying on multicast would be to define the ScaleOut host group yourself--a lot people running ScaleOut in cloud environments or locked-down virtual environments do this. You'd just need need to manually configure the cluster’s host group (a host group is a roster of IP addresses that are eligible to form a store). It's a two step process:

1. Disable multicast either through Management Console in the Host Configuration tab by unchecking the "Multicast discovery" check box, or by running the following commands on one of the hosts by using the command-line control program (soss.exe):

soss.exe leave all
soss.exe set use_multicast=0

2. Manually configure your host group. When using the ScaleOut Management Console, you can do that by clicking the Group Management tree node on the left and then building the group by adding hosts' IP addresses in the Group Management screen on the right. The first host (it does not matter which one) should create the host group, and the other(s) should add the IP address of any other host already within the group host list. For each additional host beyond the first one, the server only needs to be initially populated with one reachable host currently in the group host list; all other hosts will be automatically added for you.

Documentation for the Management Console's Group Management screen can be found here: https://static.scaleoutsoftware.com/docs/user_guide/management/winconsole.html#group-management

You can also do this with the command-line control program. On the first host (e.g., 10.0.20.1):

soss.exe create_group

…then, on every other host (e.g., 10.0.20.2):

soss.exe add_host 10.0.20.1

Once the host group is configured, all hosts will coalesce into a single multi-host store without relying on multicast.

 

[asavagemonster]

Thank you Mark - i'll pass this information along to our production engineering team and hopefully they will configure it this way.

Just for clarification purposes.. The use of Multicast is only used for gathering the Host's during discovery? So by creating the groups initially this bypasses the need for multicast all together and the app will still function the same afterwards? These are questions they will ask so i want to make sure the bases are covered. To them this would be a major change and need to go through dev/qa before it went to production.

Thank you,

Adam Savage

 

[markw]

Hi Adam,
Yes, you've got it exactly right--multicast is only used during discovery, and manually creating a group of candidate IPs is an alternative way to let the hosts find each other when they first start up. After that, everything will work the same.