Synchronisation accross servers for migration steps

Zsolt Nemeth

Vote:

Hi,

As far as I know there is no functionality in Episerver which would provide an infrastructure for migration steps aside MigrationStep, which can be only used to rename a property. Migration in my case includes setting values for new properties, copying values from one property to another (maybe on another page) and so on. Until now I used Scheduled Jobs for this, but it needs to be completely automated and run at startup.

Is there any infrastructure which I can build upon for this, aside from InitializationModule? MigrationSteps are executed on each startup, so I cannot reuse that, I need to ensure that each of my tasks are executed only once and only on one server at a time (in case of multiple servers are starting up). With the latter I am not sure how to achieve with Episerver, is there anything to synchronise across servers?

It is not purely related to CMS, I need to support Commerce Content as well, but as far as the infrastructure is concerned, it should be transparent.

Zsolt

#241040

Edited, Dec 10, 2020 10:44

Quan Mai

Vote:

Technically you can use IMigrationStep in Commerce, with some caveats (it's not officially public APIs, and it is not built to address multiple instances scenario)

#241041

Dec 10, 2020 10:49

Zsolt Nemeth

Vote:

I came across that, but it seems like something which is not fully automatic, the administrator have to start it. Or is it possible to make it automatic, without user interaction?

#241042

Dec 10, 2020 10:56

Quan Mai

Vote:

It is. You can add AutoMigrateEPiServer appSettings (and value = true of course) and the migration process will be started automatically.

#241043

Dec 10, 2020 11:09

Zsolt Nemeth

Vote:

Sounds like a good idea! One problem is still how can I ensure that it (or my custom infrastructure) is not getting run parallel on multiple instances, how can I do some kind of synchronisation across instances in code? (the point is not to trust administrators to start only one instance after deployment)

#241044

Dec 10, 2020 11:18

Quan Mai

Vote:

That part is actually tricky and not builtin. You can do some custom cross-instance lock, like checking if a special value is added to a table yet, if not, add it, otherwise just wait until it is changed to complete, for example

#244748

Dec 10, 2020 14:14

Zsolt Nemeth

Vote:

Ok, thanks for your answer and the ideas!

#244749

Dec 10, 2020 15:35

Quan Mai

Vote:

Commerce team will be looking into that as well (they are already aware it's a possible improvement), so in a future release - hopefully, you can remove the custom lock. But that'll take some time :)

#244750

Dec 10, 2020 15:46