Concurrency In Scala

Matthew Rathbone shows different concurrency options available in Scala:

Scala is a functional programming language that aims to avoid side effects by encouraging you to use immutable variables (called ‘values’), and data structures.

So by default in Scala when you build a list, array, string, or other object, that object is immutable and cannot be changed or updated.

This might seem unrelated, but think about a thread which has been given a list of strings to process, perhaps each string is a website that needs crawling.

In the Java model, this list might be updated by other threads at the same time (adding / removing websites), so you need to make sure you either have a thread-safe list, or you safeguard access to it with the protected keyword or a Mutex.

By default in Scala this list is immutable, so you can be sure that the list cannot be modified by other threads, because it cannot be modified at all.

While this does force you to program in different ways to work around the immutability, it does have the tremendous effect of simplifying thread-safety concerns. The value of this cannot be understated, it’s a huge burden to worry about thread safety all the time, but in Scala much of that burden goes away.

Read the whole thing if you’re looking at writing Spark applications in Scala.  If you’re thinking about functional programming in .NET languages, F# is  there for you.

Related Posts

Azure Functions Basics

Vincent-Philippe Lauzon explains the basics of Azure Functions: In general, serverless refers to an economical model where we pay for compute resources used as opposed to “servers”. Wait…  isn’t that what the Cloud is about? Well, yes, on a macro-scale it is, but serverless brings it to a micro-scale. In the cloud we can provision […]

Read More

Building Dynamic Row Headers With ML Services

Dave Mason tries to get around his RESULT SETS limitation when using SQL Server Machine Learning Services: The columns in the data frame clearly have names, but SQL Server isn’t using them. The data frame columns have types in R too (more on this in a moment). Now that makes me wonder about the data […]

Read More

Categories

March 2017
MTWTFSS
« Feb Apr »
 12345
6789101112
13141516171819
20212223242526
2728293031