Patterns and anti-patterns in building Akka systems

"Let it crash" Principle

• Recovery should be automatic to restore normal service as soon as possible

Inverted control flow

• Better to push jobs than to pull them
• Reduce the frequency of blocking requests
• Fit nicely with short jobs that comes at a fixed rate
• Not an adequate pattern when
• jobs are produced faster than finished
• jobs are expensive and should be avoided if possible
• Solution: push jobs after old jobs are finished
• Eg. push with rate limit / acknowledgement

Durable mailbox

• Actor system doesn't guarantee the delivery of messages per se
• Have to use additional protocols to approach this purpose
• ack everywhere
• store to persist
• Asking for guarantees in an uncertain world takes costs
• increased effort / complexity / latency
• additional dependency in the architecture

Event sourcing

• A good way to compile a list of time-series events
• Has to take care of replication inconsistency, application latency, etc

Non-blocking request

• Future-based messaging

Sentinel

• handling failure above a supervisor, flow control and distributed workers

How to Write Doc Comments for the Javadoc Tool

How to write documentations for Java codes
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html

javadoc: manual and spec
http://docs.oracle.com/javase/7/docs/technotes/tools/solaris/javadoc.htm

Smoothsort Demystified

A very nice article explaining smoothsort!

http://www.keithschwarz.com/smoothsort/

Cloud Design Patterns

http://msdn.microsoft.com/en-us/library/dn568099.aspx

"This book contains twenty-four design patterns and ten related guidance topics, this guide articulates the benefit of applying patterns by showing how each piece can fit into the big picture of cloud application architectures. It also discusses the benefits and considerations for each pattern. Most of the patterns have code samples or snippets that show how to implement the patterns using the features of Microsoft Azure. However the majority of topics described in this guide are equally relevant to all kinds of distributed systems, whether hosted on Azure or on other cloud platforms."