Hi Ryan, Transactions are within a single database, so you cannot do this as a single transaction.
You could use distributed transactions (XA), and this is really the use case it is designed for. But it might be overkill. How long do these updates take? If they only take a few seconds, you could put some logic in your application to wait until everything is committed like the following: 1) insert a document in one of the dbs that indicates that you started your updates 2) add code to your app that has a for loop that evals another query (it must be in a different transaction) to see if the above document exists, and if it does, sleep for a second, then continues in the loop. If the doc does not exist, it invokes the module (so it is in a new transaction) that was originally called. 3) do your updates to all three databases 4) delete the document added in step 1 5) delete the extra code added in step 2 It is a little hacky, but the effect will be for the few people that try to access the system during these updates, they will see a small delay in their response. You might be able to do this in a URL rewriter too. Just an idea, untried and untested. -Danny ________________________________________ From: general-boun...@developer.marklogic.com [general-boun...@developer.marklogic.com] On Behalf Of seme...@hotmail.com [seme...@hotmail.com] Sent: Wednesday, April 18, 2012 7:36 PM To: general@developer.marklogic.com Subject: [MarkLogic Dev General] Possible to coordinate an update across DBs to commit at the same time? Say I have three databases: A, B, and Modules. I want to be able to deploy changes to all three and have the changes all commit (or become active) at the same time. I may have new config files that only work with the new code going into Modules so I don't want to put the config files in A and then afterwards insert the new code in Modules because there may be a gap in time where the config files and the code are not the right versions for each other. I don't want to have any downtime so stopping the server is not really any option. How can I insert my new files across the DBs and have the changes take place simultaneously? Perhaps I can have the app run at a particular timestamp and then insert all the new files and then remove the run-at timestamp. I'm not sure this works for the Modules DB though. Another option may be to put version info in the XML files in database A, then write the new code in the Modules DB under a new directory and write the code to only use the files in A with the new version, then change the modules root of the app server to the newer code dir (thus automatically only using the new version of files in A). I'll take "within a few microseconds" if "simultaneous" isn't really possible. Anyone know how to do this? Thanks! -Ryan _______________________________________________ General mailing list General@developer.marklogic.com http://developer.marklogic.com/mailman/listinfo/general
