Hi Norbert and Mariano, thanks for the important input. I will use voyage now, just loading :-)
BTW: it is really great, getting answers in the forum so quick and profound!!! I am very happy about that. Sabine On Thu, Jul 18, 2013 at 2:57 PM, Norbert Hartl [via Smalltalk] <ml-node+s1294792n4699354...@n4.nabble.com> wrote: > > Am 18.07.2013 um 12:33 schrieb Sabine Knöfel <[hidden email]>: > >> Hi, >> >> Currently, I create one single Instance of Mongo when starting the Image. >> >> | theRoot | >> theRoot := Mongo default. >> theRoot open. >> >> and use it for all requests. In my development environment that works >> fine. >> >> My question is: is this the right way and will it work for production? > > No, certainly not. If you restart mongo db e.g. due a system update the > connection from the image would be stale serving you errors. >> Or is it better to create one Mongo instance for each request (and close >> it >> after the request)? > That is theoretically the safest thing but very expensive. Opening a > connection always takes time and consume quite some resources. So reuse is > king. >> And, btw: what would happen if I would open many Mongo connections but >> never >> close any? > You would run out of external semaphores in the image. The image is > "somewhat broken" in this regard because it cannot expand the semaphore > table. As each connection uses three semaphores you are running out of > semaphores after 85 requests. > >> Or better one Instance per user session? >> > That can be a good idea but it doesn't solve your actual problem. > > You also need to take care of concurrent requests. The line protocol to the > mongo database needs to be aligned and it is binary. If more threads try to > write on the same connection the connection will break. I'm not sure if this > is still possible in the newest MongoTalk driver nor do I know if I managed > it to release my thread safe mongo instance. > > The pool Mariano is talking about sounds like a good idea. Otherwise wrap > your store method with an exception handler to reopen a connection on > failure. > > Norbert > > > > > ________________________________ > If you reply to this email, your message will be added to the discussion > below: > http://forum.world.st/MongoDB-open-close-in-production-singleton-or-not-tp4699322p4699354.html > To unsubscribe from MongoDB open close in production (singleton or not), > click here. > NAML -- View this message in context: http://forum.world.st/MongoDB-open-close-in-production-singleton-or-not-tp4699322p4699356.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.
