Implement observation

[dantleech]

This shouldn't be too hard in theory right?

[dbu]

not so sure - its not about event listeners in the same process, but
mostly about one process listening to events coming from other
processes. in php the listening is always polling - but you would need
to record the events somewhere outside the php processes so any client
connecting to that database can also connect to the event log.

[dantleech]

But isn't doctrine-dbal its in the same process ?

[dbu]

if i have 2 webservers both talking to the same database, it won't even be on the same machine. already in one webserver we normally have several processes. plus you can have command line tools running that also do operations. observation is about the repository, not about the process - thats what i mean by its not an event listener in the symfony/doctrine sense.

[dantleech]

ok i understand. so I guess we would have to add an event log table to the implementation and then have clients check this log. Its feasable?

[dbu]

and "something" that cleans up old log entries to not explode. but yes.
a better implementation would be based on a message queue like rabbitmq
so i guess this should be done in a way that we can plug different
implementations.

[dantleech]

But would implementing another technology raise the bar a bit too far? What is conceptually wrong with just drumping it in a table? (disclaimer: I know nothing about rabbitmq :)

Jackrabbit does its own event logging I imagine?

[dbu]

with jackrabbit we get the events from the server, yes.

i agree with a simple implementation in a table, just saying we would
best build it in a pluggable way to make it easy to do a better
implementation for people who need it.

[dantleech]

So pluggable on the jackalope level?

[dbu]

yes. or the jackalope-doctrine-dbal level. i think we made it a
transport layer job.