Alfresco transactions and side effects

May 19, 2014

Alfresco has this notion of activities, which basically is stuff that’s happened in a room in which you are a member. There is an activity feed, and there is an email which is sendt out every so often which tells you what has happened since the last time the email was sendt.

The latest activity you received news about is stored in the EMAIL_FEED_ID property on your person object. So every time an activity email is sent out, this property is updated to reflect the last activity sent to you.

Unless

The class that does this job, the FeedNotifierImpl wraps each users notification-email-sender-thingy in a RetryingTransactionHelper. You can see that in there somewhere (makes you wish this was written in Clojure, right). Now, the interesting bit is that if you happen to cause an exception being thrown in while in this transaction, say by executing

try {
NodeRef p = nodeService.getParentNodeRef(nodeRef);
} catch (Exception e) {
log.warn("no parent for " + nodeRef);
}

then, even if you catch it, like shown above, Alfresco will mark the transaction as to be rolled back. This means that the EMAIL_FEED_ID will never be updated.

This might just be very correct, apart from the fact that there is stuff done in this transaction that cannot be rolled back, yes, the emails, they are already dispatched at the time of the rollback, and thus our users get activity emails with old activities in them.