Hi Spring fans and welcome to another installment of This Week in Spring! This week I'm in Chicago, New York City and Denver talking to Pivotal customers. We've got a lot of good stuff to look at this week so let's get to it!

• Spring Data ninja Thomas Risberg just announced Spring for Apache Hadoop 2.5.0.RC1. The new release is primarily a bugfix. The post looks forward to Spring for Apache Hadoop 3.0, which will be based on Spring Boot, a Java 8 baseline, Spark 2.0 integration, and Spring Batch 4.0 readers and writers.
• Spring Data ninja Mark Paluch looks at a lot of the new features in Spring Data Kay including support for fluent MongoOperations, Kotlin,smarter MongoDB collation, Java 9 compatability, and so much more.
• I liked Arnold Galovics's post on how to configure a DataSource proxy in Spring Boot.
• Kotlin's hidden costs - Benchmarks - Renato Athaydes -
• Bytecode generation on the JVM and Kotlin - This is a deep-dive into the basics of how the Kotlin-language interacts with the JVM and the compiler. Worth a read if you're diving into Kotlin (as I have been for the last few years) even if the post doesn't have a lot to do with Spring perse.
• A Spring Boot application that talks to Ethereum or Quorum network - This was an interesting Spring Boot application that talks to an Ethereum or Quorum network.
• In Redmonk's latest look at Java language and framework popularity, Spring and Spring Boot seem to be doing quite well!
• Mark Heckler looks at serving XML in REST APIs in this useful post
• I liked this post on using the Quartz scheduling API. It starts from the basic usage and eventually gets all the way through to the Spring Boot experience. Nice!
• I liked this presentation on the basics of Chaos Engineering by Tammy Butow.
• What if an application could automatically repel attackers by rotating its access credentials every day, thereby making every stolen password useless in a short amount of time? That’s the idea behind CredHub, a new feature introduced for Pivotal Cloud Foundry today. Read the rest of this VentureBeat article for more.
• Dormain Drewitz chimes in with a look at some Secrets of successful Cloud Foundry users from the recent Cloud Foundry Summit