Bigdata roundtable-storm

Storm - pipes andﬁlters on steroids Andre Sprenger BigData Roundtable Hamburg 30. Nov 2011

My background• info@andresprenger.de• Studied Computer Science and Economics• Background: banking, ecommerce, online advertising• Freelancer• Java, Scala, Ruby, Rails• Hadoop, Pig, Hive, Cassandra

“Next click” problemRaymie Strata (CTO,Yahoo):“With the paths that go through Hadoop [at Yahoo!], thelatency is about ﬁfteen minutes. … [I]t will never be truereal-time. It will never be what we call “next click,” whereI click and by the time the page loads, the semanticimplication of my decision is reﬂected in the page.”

“Next click” problem (next) HTTP HTTP HTTP HTTPRequest Response Request Response max latency max latency 80 ms 80 ms web server realtime near realtime response response real time layer collect data process data time

Example problems• Realtime statistics - counting, trends, moving average• Read Twitter stream and output images that are trending in the last 10 minutes• CTR calculation - read ad clicks/ad impressions and calculate new click through rate• ETL - transform format, ﬁlter duplicates / bot trafﬁc, enrich from static data, persist• Search advertising

Pick your framework...• S4 - Yahoo, “real time map reduce”, actor model• Storm - Twitter• MapReduce Online - Yahoo• Cloud Map Reduce - Accenture• HStreaming - Startup, based on Hadoop• Brisk - DataStax, Cassandra

System requirements• Fault tolerance - system keeps running when a node fails• Horizontal scalability - should be easy, just add a node• Low latency• Reliable - does not loose data• High availability - well, if it’s down for an hour its not realtime

Storm in a nutshell• Written by Backtype (aquired by Twitter)• Open Source, Github• Runs on JVM• Clojure, Python, Zookeeper, ZeroMQ• Currently used by Twitter for real time statistics

Programming model• Tuple - name/value list• Stream - unbounded sequence of Tuples• Spout - source of Streams• Bolt - consumer / producer of Streams• Topology - network of Streams, Spouts and Bolts

Spout tuple tuple tuple tupleSpout tuple tuple tuple tuple

Bolt Processes streams and generates new streams.tuple tuple tuple tuple tuple tuple tuple tuple Bolttuple tuple tuple tuple

Bolt• ﬁltering• transformation• split / aggregate streams• counting, statistics• read from / write to database

TopologyNetwork of Streams, Spouts and Bolts Bolt Bolt Spout Bolt Spout Bolt Bolt

TaskParallel processor inside Spouts and Bolts.Each Spout / Bolt has a ﬁxed number of Tasks. Spout Bolt Task Task Task Task Task

Stream groupingWhich Task does a Tuple go to?• shuffle grouping - distribute randomly• field grouping - partition by field value• all grouping - send to all Tasks• custom grouping - implement your own logic

Word count example Sentence Word (“a”, 2) Splitter Count (“b”, 2)Spout Bolt Bolt (“c”, 1) (“a”) (“d”, 1) (“b”) (“a b c a b d”) (“c”) (“a”) (“b”) (“d”)

Guaranteed processing (“a”) (“b”) (“a”, 2) (“c”) (“b”, 2)Spout (“a b c a b d”) (“c”, 1) (“a”) (“d”, 1) (“b”) (“d”)Topology has a timeout for processing of the tuple tree

Runtime view

Reliability• Nimbus / Supervisor are SPOF• both are stateless, easy to restart without data loss• Failure of master node (?)• Running Topologies should not be affected!• Failed Workers are restarted• Guaranteed message processing

Administration• Nimbus / Supervisor / Zookeeper need monitoring and supervisor (e.g. Monit)• Cluster nodes can be added at runtime• But: existing Topologies are not rebalanced (there is a ticket)• Administration web GUI

Community• Source is on Github - https://github.com/ nathanmarz/storm.git• Wiki - https://github.com/nathanmarz/storm/wiki• Nice documentation• Google Group• People start to build add-ons: JRuby integration, adapters for JMS, AMQP

Storm summary• Nice programming model• Easy to deploy new topologies• Horizontal scalability• Low latency• Fault tolerance• Easy to setup on EC2

Questions?

Bigdata roundtable-storm

by Tobias Schlottke

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