Hi Update on this one.
We implemented a generic pooling in Camel naming it Service Pool. Details in the wiki page: http://camel.apache.org/servicepool.html On Mon, May 25, 2009 at 3:10 PM, Claus Ibsen <claus.ib...@gmail.com> wrote: > Hi > > I have looked into this a bit more. > > With this we can support correlation for concurrent request/response > with mina as well. A feature that was generelly lacking there. > > So this is definitely a great step in a good direction for Camel. > > This feature has been tracked here: > http://fusesource.com/issues/browse/MR-18 > > > > On Mon, May 25, 2009 at 10:19 AM, Claus Ibsen <claus.ib...@gmail.com> wrote: >> Hi >> >> A recent bug was reported in ticket CAMEL-1641 >> https://issues.apache.org/activemq/browse/CAMEL-1641 >> >> The issue is in Camel 2.0 the FTP producer is not thread safe, in the >> sense that you cannot concurrently send at the same time to the same >> FTP endpoint. >> >> I have digged into this issue and discovered the issue lies in the >> fact that the FtpProducer cannot be singleton scoped. It uses a local >> FTPClient that is used for the FTP communication. >> >> A given endpoint producer is however stored in either a producer cache >> or as a class instance variable in SendProcessor. >> This causes the issue that a non singleton producer will be reused for >> concurrent threads. >> >> So to remedy this I have done some code as a prototype that I usually >> do during my findings. >> >> We extend the concept of IsSingleton from Endpoint to Producer as >> well. Then we can set it as false for FtpProducer. >> We let the producer cache detect the IsSingleton and only cache singletons. >> >> I have also added a ProducerCallback interface that resembles the >> Spring resource patterns for its JmsTemplate, JdbcTemplate etc with >> its doInXXXX >> >> public interface ProducerCallback<T> { >> >> /** >> * Performs operation on the given producer to send the given exchange. >> * >> * @param producer the producer, is newer <tt>null</tt> >> * @param exchange the exchange, can be <tt>null</tt> if so then >> create a new exchange from the producer >> * @param exchangePattern the exchange pattern, can be <tt>null</tt> >> * @return the response >> * @throws Exception if an internal processing error has occurred. >> */ >> T doInProducer(Producer producer, Exchange exchange, >> ExchangePattern exchangePattern) throws Exception; >> } >> >> With this callback it allows a producer client to safely use the >> producer without having to worry about how to start and stop the >> resource whether its singleton or not. >> >> And in the future we can incorporate a pooling as well so Camel can >> leverage pooling with this pattern. So Camel can safely obtain a >> producer from the pool, invoke this callback where the client/user can >> use it to do what is needed, usually to send an exchange. And >> afterwards Camel can safely return the producer back to the pool. >> >> However I know this is kinda expanding Camel out of its current scope. >> There is a tiny concept of IoC or resource/lifecycle handling in here. >> >> >> Another idea is also to denote the ProducerCache as a higher role. We >> could let CamelContext be able to hold a per context producer cache >> and let it provide this cache where its needed in: ProducerTemplate, >> SendToProcessor and a few other areas. This allows us to reuse this >> cache instead of having a per local cache. >> >> >> Well a few concepts to grasp. I will create a ticket for this and >> attach a patch for people to look at. >> >> >> Any thoughts? >> >> >> >> >> >> -- >> Claus Ibsen >> Apache Camel Committer >> >> Open Source Integration: http://fusesource.com >> Blog: http://davsclaus.blogspot.com/ >> Twitter: http://twitter.com/davsclaus >> > > > > -- > Claus Ibsen > Apache Camel Committer > > Open Source Integration: http://fusesource.com > Blog: http://davsclaus.blogspot.com/ > Twitter: http://twitter.com/davsclaus > -- Claus Ibsen Apache Camel Committer Open Source Integration: http://fusesource.com Blog: http://davsclaus.blogspot.com/ Twitter: http://twitter.com/davsclaus
