Thanks Nathan and Javier. I ended up using lazy init singleton and things seem to be working. But now how do I know its using single instance of the session? Is there a way we can know from storm UI or and where else?
-- Kushan Maskey 817.403.7500 Precocity LLC <http://precocity.com> M. Miller & Associates <http://mmillerassociates.com/> kushan.mas...@mmillerassociates.com On Thu, Jun 18, 2015 at 12:48 PM, Javier Gonzalez <jagon...@gmail.com> wrote: > We had a similar issue (namely, you can't pass anything non-serializable > through the Configuration or create it in the constructor). > > What we did is pass in the Configuration or constructor a String with the > path to a properties file. From that configuration file, in the > bolt.prepare method you bring up whatever you need (such as a connection > pool) and off you go. We needed to use a library that was configured by > spring, so we passed in the path to the spring configuration file, created > a context with it in the prepare method, obtained the external beans, and > closed the context. > > On Wed, Jun 17, 2015 at 5:16 PM, Nathan Leung <ncle...@gmail.com> wrote: > >> You cannot pass a connection through the builder, as you have noticed. >> You can use a lazy initialized singleton or some sort of connection pool. >> On Jun 17, 2015 5:05 PM, "Kushan Maskey" < >> kushan.mas...@mmillerassociates.com> wrote: >> >>> I am wondering how can I safely create a Singleton database connection >>> and use it through out the process. >>> >>> Here is my scenario. >>> >>> I got bunch of bolts that updates Cassandra database. I have reader and >>> writer classes where each needs a database session to execute queries. We >>> create session on each of the reader and writer classes. We also use >>> parallelism hints on the bolts which create that many instances of session >>> object. >>> >>> I have tried creating session on topology and pass the instance through >>> stormConfig but didnt work with the error message below. >>> >>> java.lang.IllegalArgumentException: Topology conf is not >>> json-serializable >>> at >>> backtype.storm.testing$submit_local_topology.invoke(testing.clj:251) >>> ~[storm-core-0.9.2-incubating.jar:0.9.2-incubating] >>> at >>> backtype.storm.LocalCluster$_submitTopology.invoke(LocalCluster.clj:38) >>> ~[storm-core-0.9.2-incubating.jar:0.9.2-incubating] >>> at backtype.storm.LocalCluster.submitTopology(Unknown Source) >>> ~[storm-core-0.9.2-incubating.jar:0.9.2-incubating] >>> >>> Any code sample will be helpful. >>> >>> -- >>> Kushan Maskey >>> 817.403.7500 >>> Precocity LLC <http://precocity.com> >>> M. Miller & Associates <http://mmillerassociates.com/> >>> kushan.mas...@mmillerassociates.com >>> >> > > > -- > Javier González Nicolini >
