Possible to mirror Ensemble and Iris?

Question

Question

Nicki Vallentgoed · Jun 27, 2022

#Mirroring #Ensemble #InterSystems IRIS for Health

Is it possible to mirror the same database on Iris and an older Ensemble instance?

Specifically to try a zero downtime upgrade

Product version: IRIS 2022.1

$ZV: IRIS for UNIX (Red Hat Enterprise Linux for x86-64) 2021.1.1 (Build 324U) Thu Feb 24 2022 13:20:39 EST

Discussion (6)2

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Guilherme Koerber · Jun 27, 2022

Hi Nicki!

Is your idea to mirror the Ensemble tables with Iris? If yes, you can do that with the table linking wizard.

https://docs.intersystems.com/ens201815/csp/docbook/DocBook.UI.Page.cls?...

I did this procedure a few times with ODBC, it's very useful.

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Herman Slagman · Jun 27, 2022

Yes, it can, ECP seems to be compatible between IRIS and Ensemble (or Cache)
We will use it for migration to IRIS too, first add an IRIS ASync member to the mirror and then later promote it.
We only have done this in a test scenario, so no guarantee ;-)

Herman

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Erik Hemdal · Jun 30, 2022

Nicki, I would start with your account manager and have a chat about how best to migrate. Since Ensemble and IRIS for Health are different products, the specific versions involved matter a great deal. A sales engineer on your account team probably has seen migrations such as the one you propose.

As for differences between IRIS and Ensemble, check the Migration Guide which you can download from the WRC. There's a lot there, but it includes the result of a lot of testing and migration experience.

And of course, if you are finding something that doesn't work as it should, reach out to the WRC.

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score 0 · Answer 1 · 2022-06-27T08:55:33-04:00

Apparently no:

https://docs.intersystems.com/irislatest/csp/docbook/DocBook.UI.Page.cls...

Some globals have different names in IRIS, apart from other differences, it might be possible to make it work but it doesn't seem like a good idea.

score 0 · Answer 2 · 2022-06-27T13:48:48-04:00

The link you added says about compatibility with version 2018.1 in Async mode, and it's the latest version of Caché/Ensemble. And in fact, renamed globals are not an issue in most cases, those globals are mostly temporary and not mirrored. So, theoretically, it should work.

score 0 · Answer 3 · 2022-06-30T07:39:44-04:00

Nope, does not seem to work.

Creating the async goes fine but as soon as I promote it, primary ensemble sees it as down.

You can also not revert back to an async afterwards.