I do not see a native way to stream data from a database in Storm. There is a JDBC connector but it is for Insert of results and lookups. Its not impossible however. Other streaming products I worked with in the past could stream from a database. ( Essentially by specifying WHERE conditions or requerying the same table every x seconds) So you could definitely implement a storm bolt like that. Depending on data volumes you might have to partition the load similar to Sqoop does it ( having multiple spouts that read with a where condition by some id ) or if the volumes are not too large just have a single spout. If it is a simple single connection example I am sure you could implement it in very short time. http://storm.apache.org/documentation/storm-jdbc.html If I was to implement an JDBCSpout I would use the Twitter Example from here and replace the Twitter code with a JDBC connection being opened against DB2. If you read some kind of staging table that gets refreshed every x seconds you would read it completely and then check if a specific amount of time has passed ( the nextTuple method is called continuously ) . If you only want to read new tuples you would have to add a WHERE condition based on some timestamp in the DB2 table. It has also some pointers how to make parallel Spouts in case a single connection is not fast enough. https://github.com/storm-book/examples-ch04-spouts https://www.safaribooksonline.com/library/view/getting-started-with/9781449324025/ch04.html ... View more

Not completely sure what you mean but it is possible to create separate config groups for these two hosts. ( Manage Config Groups at the top of the config page ). This means you could create a config for host1 and a different config for host2. I don't think its possible to start/stop them separately through ambari though. Unless you go directly to the host and start/stop them there. ... View more

Essentially Ambari uses something called stacks. It is a module that governs one of the services in the cluster with functions to install/start/stop dependencies etc. Unlike parcels Most of the stacks are based on yum/zypper packages under the cover for install which is nice and linux standard. https://cwiki.apache.org/confluence/display/AMBARI/Stacks+and+Services Not too familiar with parcels but I would think that is more or less the equivalent? Just to consolidare the comment below, here are some example stacks by @Ali Bajwa https://github.com/abajwa-hw/ambari-workshops And another helpful article: http://mozartanalytics.com/how-to-create-a-software-stack-for-ambari/ ... View more