Planning and Migration from Server to Datacenter

[Chris N_]

We currently are running Jira (server edition) on our own on-premise infrastructure. We are planning on migrating the environment to a single-node, on-premise Datacenter instance of JIRA but I'm having trouble figuring out the size of the VM needed and the method of upgrade. 

I've heard from different sources that a new VM would need to be spun up and the data migrated from the server edition to the datacenter edition. In some areas I've noticed that for a non-clustered, non-cloud version we may be either able to just upgrade our license and/or upgrade the software on the existing VM and not need to go through a migration process. 

Because of infrastructure limitations, NOT having to spin up a new VM and have them run in parallel for the migration period would be HUGE. Does anyone have or know of the steps needed to upgrade a non-clustered on-premise JIRA server instance to a non-clustered, on-premise Datacenter JIRA instance (ideally with as little headache as possible)?

In terms of sizing, our current JIRA version that's servicing around ~300 users runs perfectly fine on a Windows Server 2016 VM with 2 CPU sockets and 6GB of RAM. I'm wondering if the apps, use, and user numbers won't be changing if Datacenter would require substantially more resources? If so, what should I look to allocate to either a net-new VM or to bump up my existing JIRA server?

Any assistance or recommendations would be sincerely appreciated. Because we can no longer purchase server licenses, many members of my team can no longer gain access to the Service Desk and now need to expedite the migration process to Datacenter. 

[Nic Brough -Adaptavist-]

Welcome to the Atlassian Community!

There are three shortcuts you can take here.

We used to recommend "size each node as though it were a single node server".  That still actually stands, but the numbers have changed a little, and have a read through https://confluence.atlassian.com/enterprise/jira-data-center-size-profiles-955171062.html

In other words, if your current server is about the right size, and appears to be running ok, you can go with that!

The second shortcut is probably the one you're going to like.  If you are on Jira 8.6 or above, you can use it (from memory, it was a bit flaky in the first version Atlassian put this into, but the problems went away in later versions, don't think I've heard of a problem since 8.5).

Your migration process can be as simple as:

1.  Check all your apps are DC compatible (including any Scriptrunner scripts if you have SR).  Work out how to remove/replace any that are not.

2.  Apply the DC licence to Jira

3.  Apply the DC licences for your apps to Jira

... and you now have a single-node DC cluster running.

You should plan "down time" for steps 2 and 3, but that's only because your apps will stop working until they get their DC licence applied, and that's going to take a good 5-10 minutes.

You should, of course, also look at the database server, you probably want that to be a cluster as well, and you'll want to look at hooking up a load balancer, but the basic "server -> node " is done!

Now, if you do want to move to new hardware, you can use the third shortcut.  Set up the new hardware, and add it as a node into the cluster.  Run the two (or more) nodes as a cluster for a while so everything syncs up.  Then pull the old machine out of the cluster and repurpose/recycle/get-rid-of it!

[Chris N_]

Thank you Nic, that was extremely helpful. The upgrade path isn't looking as grim as I feared. 

Unfortunately, we aren't currently running on 8.6 (specifically we are on 8.5.3). Do you know if a Datacenter license can be applied to that version without causing any issues or do we NEED to get onto at least 8.6 before we can look to apply the DC license?

I'm concerned that because we have the perpetual "server" license that when we do the upgrade to 8.6 that it won't accept anything but a Data Center license, or that when we upgraded last time that our perpetual license is locked into only Jira 8.5.X