License Transfer & Reading NoSQL Data from other Instance

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Hello,

I have a question around a license transfer and if it will allow a new install/instance of Mango to read all of the NoSQL data from an inactive instance (the instance that originally had the license). The post listed below makes it sound like this is the case, but want to make sure.

https://forum.infiniteautomation.com/topic/2280/migrating-nosql-data-store-license-from-one-mango-instance-to-another/2

Here's the scenario I have. Since Mango cannot be load balanced, we plan to have a "dark" server with Mango installed, but not running. If there's an issue with the primary server, we want to quickly (~30 seconds) move over to the dark server. If transferring the license to the new server will allow us to continue to read all of the data, that would help a lot.

Let me know any thoughts.

Thanks,
Chad

Hi Chad

When you say transferring the licences to do you mean ftp'ing the licence file over to the redundant server? if so the licences file will not be valid for that server.

Hi, Craig,

To be honest, I'm not sure. I just read a blurb from the thread I linked to in the original post and thought it sounded like a license could be transferred between servers so data from the original server would be visible to the new.

I guess my question should be reworded to, "Is there a way to shut down one instance of Mango and have a 2nd instance, on a separate server, see the data from the original without doing a NoSQL import?" The assumption is that the original server would not come back online.

Thanks,
Chad

The thread you linked to was asking if IAS can transfer their licence from one instance to another which is a manual request you can do.

I'm curious is the goal to have hardware redundancy with only one software licence? I am not so sure this would work with mango's licencing.
Are these cloud servers or self-hosted servers?

Yes, I wanted to see if it were possible to have one software license that could move from server to server if there were a failure on the active server. The goal really is to have the second instance be able to read and write to the NoSQL data from the first instance if it goes down.

The scenario I have is on AWS servers.

AWS does have volumes that can be mounted to multiple servers. I just googled this now so depending on how good your devOps skills are you could find a solution with the EFS storage. https://aws.amazon.com/efs/

Yes, we have that and tested it out, but what we found is that with Mango, one instance cannot read the data from another. How can we get one instance of Mango to read the NoSQL data of another instance?

Im not sure what you mean by one instance cannot read data from another instance. 2 different mango installations both pointing to the same databases directory will definitely work as long as you only run one at a time.

Maybe we have something set up wrong, because that definitely is not the case.

We have instance A running on server A, writing to the NoSQL file system. We shut down server A and start up server B and instance B. Instance B can write to the same NoSQL file system, but not as instance A.

Instance B cannot read the data from instance A. Instance B saves the new data as a separate instance.

Is there a setting or something we're missing that would allow instance B to read the NoSQL data from instance A after instance A is shut down?

Your "instances" altho I would prefer the term "mango modules" would need to share the same H2 or MySQL database depending on what is being used. This would make them identical running on different servers.
This will not get past the licencing issue tho, licenses are issued per server.

They do share the same MySQL Server.

That was my original question. Can we do a license transfer or something else to allow the NoSQL data of an inactive Mango Module to be read by an active Mango Module?

Doing a NoSQL import seems like a lot of effort for something that should be native to the app. Is there no way to do a license transfer at the Mango Module level?

Your original question was answered. You can manually request a licence transfer from one instance to another. As well as mount the volume with the NoSQL database on to the standby server. I'm not sure what you have tried so far but moving databases from one server to another shouldn't give you any issues.

Okay, thank you. So we have to go through you guys for a license transfer and can't do that on our own? We'll take that into consideration on our setup.