Skip to main content

Distributed data processing with Apache Flink

By Sachin Ghai
A new distributed engine named Apache Flink has been making its presence felt in the Hadoop ecosystem primarily due to its faster processing and expressive coding capabilities. To get a better idea on Apache Flink design and integration, HadoopSphere caught up with PMC chair Stephan Ewen and asked him more about the product. This is the first part of the interaction with Ewen where we ask him on technical aspects of Apache Flink.

How does Apache Flink work?


Flink is a distributed engine for batch and stream data processing. Its design draws inspiration from MapReduce, MPP databases, and general dataflow systems. Flink can work completely independent of existing technologies like Hadoop, but can run on top of HDFS and YARN.

Developers write Flink applications in fluent APIs in Java or Scala, based on parallel collections (data sets / data streams). The APIs are designed to feel familiar for people who know Hadoop, Apache Spark, Google Dataflow or SQL. For the latter, Flink adds a twist of SQL-style syntax to the API, with richer data types (beyond key/value pairs) whose fields can be used like attributes in SQL. Flink’s APIs also contain dedicated constructs for iterative programs, to support graph processing and machine learning efficiently.

Rather than executing the programs directly, Flink transforms them into a parallel data flow - a graph of parallel operators and data streams between those operators. The parallel data flow is executed on a Flink cluster, consisting of distributed worker processes, much like a Hadoop cluster.

Flink’s runtime is designed with both efficiency and robustness in mind, integrating various techniques in a unique blend of data pipelining, custom memory management, native iterations, and a specialized serialization framework. The runtime is able to exploit the benefits of in-memory processing, while being robust and efficient with memory and shuffles.

For batch programs, Flink additionally applies a series of optimizations while transforming the user programs to parallel data flow, using techniques from SQL databases, applied to Java/Scala programs. The optimizations are designed to reduce data shuffling or sorting, or automatically cache constant data sets in memory, for iterative programs.

What are the integration options available with Apache Flink?


Unlike MapReduce programs, Flink programs are embedded into regular Java/Scala programs, making them more flexible in interacting with other programs and data sources.

As an example, it is possible to define a program that starts with some HDFS files and joins in a SQL (JDBC) data source. Inside the same program, one can switch from the functional data set API to a graph processing paradigm (vertex centric) to define some computations, and then switch back to the functional paradigm for some the next steps. 

The Flink community is also currently working on integrating SQL statements into the functional API.





Stephan Ewen is committer and Vice President of Apache Flink and co-founder and CTO of data Artisans, a Berlin-based company that is developing and contributing to Apache Flink. Before founding data Artisans, Stephan was leading the development of Flink since the early days of the project (then called Stratosphere). Stephan holds a PhD in Computer Science from the University of Technology, Berlin, and has been with IBM Research and Microsoft Research in the course of several internships.

Labels:

Comments

Post a Comment

Popular articles

5 online tools in data visualization playground

By Sachin Ghai
While building up an analytics dashboard, one of the major decision points is regarding the type of charts and graphs that would provide better insight into the data. To avoid a lot of re-work later, it makes sense to try the various chart options during the requirement and design phase. It is probably a well known myth that existing tool options in any product can serve all the user requirements with just minor configuration changes. We all know and realize that code needs to be written to serve each customer’s individual needs.
To that effect, here are 5 tools that could empower your technical and business teams to decide on visualization options during the requirement phase. Listed below are online tools for you to add data and use as playground.
1)      Many Eyes: Many Eyes is a data visualization experiment by IBM Researchandthe IBM Cognos software group. This tool provides option to upload data sets and create visualizations including Scatter Plot, Tree Map, Tag/Word cloud and ge…
6 comments
Read more

Data deduplication tactics with HDFS and MapReduce

By Sachin Ghai
As the amount of data continues to grow exponentially, there has been increased focus on stored data reduction methods. Data compression, single instance store and data deduplication are among the common techniques employed for stored data reduction.
Deduplication often refers to elimination of redundant subfiles (also known as chunks, blocks, or extents). Unlike compression, data is not changed and eliminates storage capacity for identical data. Data deduplication offers significant advantage in terms of reduction in storage, network bandwidth and promises increased scalability.
From a simplistic use case perspective, we can see application in removing duplicates in Call Detail Record (CDR) for a Telecom carrier. Similarly, we may apply the technique to optimize on network traffic carrying the same data packets.
Some of the common methods for data deduplication in storage architecture include hashing, binary comparison and delta differencing. In this post, we focus on how MapReduce and…
2 comments
Read more

Hadoop's 10 in LinkedIn's 10

By Sachin Ghai
LinkedIn, the pioneering professional social network has turned 10 years old. One of the hallmarks of its journey has been its technical accomplishments and significant contribution to open source, particularly in the last few years. Hadoop occupies a central place in its technical environment powering some of the most used features of desktop and mobile app. As LinkedIn enters the second decade of its existence, here is a look at 10 major projects and products powered by Hadoop in its data ecosystem.
1)      Voldemort: Arguably, the most famous export of LinkedIn engineering, Voldemort is a distributed key-value storage system. Named after an antagonist in Harry Potter series and influenced by Amazon’s Dynamo DB, the wizardry in this database extends to its self healing features. Available in HA configuration, its layered, pluggable architecture implementations are being used for both read and read-write use cases.
2)      Azkaban: A batch job scheduling system with a friendly UI, Azkab…
Post a Comment
Read more