Using your example: HDP 2.3.4.0-3485: HDP Major Version 2 -- Version 2 is defined by the introduction of YARN with Hadoop 2. HDP Minor Version 3 -- a Feature Bearing release. New features were introduced in this release. You can see a summary of what was introduced as part of HDP 2.3 in this blog: http://hortonworks.com/blog/available-now-hdp-2-3/ HDP Maintenance Release 4 -- maintenance releases contain both defect fixes reported by our customers through our support team and proactive fixes from the various Apache community that are deemed important by the Hortonworks engineering team. Maintenance releases are cumulative -- all fixes delivered in HDP 2.3.4 are also in HDP 2.3.6. HDP 2.3.6 You can see what patches are included above and beyond the core Apache Versions by reviewing the release notes: Release Notes HDP 2.3.4 - Apache Patch Information In addition, you can see what was specifically fixed based on customer cases reported in the Fixed Issues section of the release notes: Release Notes HDP 2.3.4 - Fixed Issues HDP Patch Level 0 -- patches are provided to one or more customers to address defects and are typically triggered via support cases logged with the Hortonworks support team. Patches are NOT cumulative. Patches are rolled up into maintenance releases and ultimately made available for all customers. Occasionally, a significant defect may be uncovered and because of its critical nature, Hortonworks decides to release a specifically patched version of HDP. This occurred with HDP 2.3.4.7 -- and I'm flagging this because you are on HDP 2.3.4.0. We recommend moving to the patch release or beyond to address these issues. You can see the details in the Release Notes for HDP 2.3.4.7. HDP Build Number -3485 -- The "-####" after the HDP version information is the specific build number that was made available. As we go through the process of pulling code from the various Apache Software Foundation projects and assembling and testing everything together, each release gets a unique build number so that we can identify one set of bits from another. The GA release of HDP 2.3.4.0 was from build 3,485 of the software. Hope that clarifies things. I also recommend that you review additional commentary that I posted regarding our release strategy when HDP 2.4 was announced. You may be interested in how this relates to the Major and Minor Versions going forward. We are on the road to HDP 3.... ... View more

Again -- there will be further maintenance releases on 2.3 which align bug fixes for components in common with future feature bearing releases such as 2.4, 2.5, etc. ... View more

You need to upgrade Ambari to 2.2.1.x -- this is because there is a newer version of Spark in the HDP 2.4 stack definition. The primary reason to upgrade to HDP 2.4.x is to obtain the latest version of Spark (1.6.x). If you aren't going to use the latest Spark, I would recommend sticking with the 2.3.x line. ... View more

As of HDP 2.3 (with Knox 0.6.0) -- a new extensibility mechanism was introduced which will allow you to add new REST APIs to be protected by Knox. Ideally, we will integrate Falcon and Knox as part of a future release -- so this comes out of the box, but until then --- have a look at this: http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.4.0/bk_Knox_Gateway_Admin_Guide/content/adding_new_service_knox_gateway.html ... View more

Available on the Add-ons page: http://hortonworks.com/hdp/addons/ ... View more