7 key recipes for data engineering
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The document outlines seven key recipes for data engineering, emphasizing that it is crucial for organizational data access rather than solely supporting data scientists. It discusses optimization practices, staging of data, the use of RDDs versus DataFrames, and the importance of data quality and creating resilient data pipelines. Jonathan Winandy shares insights and tips gathered from his expertise and experiences in the field.
![1.It’s all about our Organisations
Data engineering is not a support
function
for Data Scientists[1].
[1] whatever they are nowadays](https://image.slidesharecdn.com/7keyrecipesfor0bdataengineering-161223164715/85/7-key-recipes-for-data-engineering-8-320.jpg)
![5. Cogroup all the things
join (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,( A , B ))]
leftJoin (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,( A ,Option[B]))]
rightJoin (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,(Option[A], B) )]
outerJoin (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,(Option[A],Option[B]))]
cogroup (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,( Seq[A], Seq[B]))]
groupBy (rdd:RDD[(K,A)]):RDD[(K,Seq[A])]
On cogroup and groupBy, for a given key:K, there is only one
unique row with that key in the output dataset.](https://image.slidesharecdn.com/7keyrecipesfor0bdataengineering-161223164715/85/7-key-recipes-for-data-engineering-33-320.jpg)
![6. Inline data quality
case class FixeVisiteur(
devicetype: String,
isrobot: Boolean,
recherche_visitorid: String,
sessions: List[FixeSession]
) {
def recherches: List[FixeRecherche] = sessions.flatMap(_.recherches)
}
object FixeVisiteur {
@autoBuildResult
def build(
devicetype: Result[String],
isrobot: Result[Boolean],
recherche_visitorid: Result[String],
sessions: Result[List[FixeSession]]
): Result[FixeVisiteur] = MacroMarker.generated_applicative
}
Example :](https://image.slidesharecdn.com/7keyrecipesfor0bdataengineering-161223164715/85/7-key-recipes-for-data-engineering-40-320.jpg)
![6. Inline data quality
case class Annotation(
anchor: Anchor,
message: String,
badData: Option[String],
expectedData: List[String],
remainingData: List[String],
level: String @@ AnnotationLevel,
annotationId: Option[AnnotationId],
stage: String
)
case class Anchor(path: String @@ AnchorPath,
typeName: String)](https://image.slidesharecdn.com/7keyrecipesfor0bdataengineering-161223164715/85/7-key-recipes-for-data-engineering-41-320.jpg)
![6. Inline data quality
Data quality is available within the output rows.
case class HVisiteur(
visitorId: String,
atVisitorId: Option[String],
isRobot: Boolean,
typeClient: String @@ TypeClient,
typeSupport: String @@ TypeSupport,
typeSource: String @@ TypeSource,
hVisiteurPlus: Option[HVisiteurPlus],
sessions: List[HSession],
annotations: Seq[HAnnotation]
)](https://image.slidesharecdn.com/7keyrecipesfor0bdataengineering-161223164715/85/7-key-recipes-for-data-engineering-43-320.jpg)
7 key recipes for data engineering
- 1. 7 Key Recipes for Data Engineering
- 2. Introduction We will explore 7 key recipes about Data Engineering. The 5th is absolutely game changing!
- 3. Thank You Bachir AIT MBAREK BI and Big Data Consultant
- 4. About Me Jonathan WINANDY Lead Data Engineer: - Data Lake building, - Audit / Coaching, - Spark Training. Founder of Univalence (BI / Big Data) Co-Founder of CYM (IoT / Predictive Maintenance), Craft Analytics† (BI / Big Data), and Valwin (Health Care Data).
- 5. 2016 has been amazing for Data Engineering ! but ...
- 6. 1.It’s all about our organisations!
- 7. 1.It’s all about our Organisations Data engineering is not about scaling computation.
- 8. 1.It’s all about our Organisations Data engineering is not a support function for Data Scientists[1]. [1] whatever they are nowadays
- 9. 1.It’s all about our Organisations Instead, Data engineering enables access to Data!
- 10. 1.It’s all about our Organisations access to Data … in complex organisations. Product OpsBI You Marketing data new data
- 11. Holding 1.It’s all about our Organisations access to Data … in complex organisations. Marketing Yo u data new data Entity 1 MarketingIT Entity N MarketingIT
- 12. 1.It’s all about our Organisations access to Data … in complex organisations. It’s very frustrating! We run a support group meetup if you are interested : Paris Data Engineers!
- 13. 1.It’s all about our Organisations Small tips : Only one hadoop cluster (no TEST/REC/INT/PREPROD). No Air-Data-Eng, it helps no one. Radical transparency with other teams. Hack that sh**.
- 14. 2. Optimising our work
- 15. 2. Optimising our work There are 3 key concerns governing our decisions : Lead time Impact Failure management
- 16. 2. Optimising our work Lead time (noun) : The period of time between the initial phase of a process and the emergence of results, as between the planning and completed manufacture of a product. Short lead times are essential! The Elastic stack helps a lot in this area.
- 17. 2. Optimising our work Impact To have impact, we have to analyse beyond immediate needs. That way, we’re able to provide solutions to entire kinds of problems.
- 18. 2. Optimising our work Failure management Things fail, be prepared! On the same morning the RER A public transports and our Hadoop job tracker can fail. Unprepared failures may pile up and lead to huge wastes.
- 19. 2. Optimising our work “What is likely to fail?” $componentName_____ “How? (root cause)” “Can we know if this will fail?” “Can we prevent this failure?” “What are the impacts?” “How to fix it when it happens?” “Can we facilitate today?” How to mitigate failure in 7 questions.
- 20. 2. Optimising our work Track your work!
- 21. 3. Staging the Data
- 22. 3. Staging the data Data is moving around, freeze it! Staging changed with Big Data. We moved from transient staging (FTP, NFS, etc.) to persistent staging in distributed solutions: ● In Streaming with Kafka, we may retain logs in Kafka for several months. ● In Batch, staging in HDFS may retain source Data for years.
- 23. 3. Staging the data Modern staging anti-pattern : Dropping destination places before moving the Data. Having incomplete data visible. Short log retention in streams (=> new failure modes). Modern staging should be seen as a persistent data structure.
- 24. 3. Staging the data HDFS staging : /staging |-- $tablename |-- dtint=$dtint |-- dsparam.name=$dsparam.value |-- ... |-- ... |-- uuid=$uuid
- 25. 4. Using RDDs or Dataframes
- 26. 4. Using RDDs or Dataframes Dataframes have great performance, but are untyped and foreign. RDDs have a robust Scala API, but are a pain to map from data sources. btw, SQL is AWESOME
- 27. 4. Using RDDs or Dataframes Dataframes RDDs Predicate push down Types !! Bare metal / unboxed Nested structures Connectors Better unit tests Pluggable Optimizer Less stages SQL + Meta Scala * Scala
- 28. 4. Using RDDs or Dataframes We should use RDDs in large ETL jobs : Loading the data with dataframe APIs, Basic case class mapping (or better Datasets), Typesafe transformations, Storing with dataframe APIs
- 29. 4. Using RDDs or Dataframes Dataframes are perfect for : Exploration, drill down, Light jobs, Dynamic jobs.
- 30. 4. Using RDDs or Dataframes RDD based jobs are like marine mammals.
- 31. 5. Cogroup all the things
- 32. 5. Cogroup all the things The cogroup is the best operation to link data together. It changes fundamentally the way we work with data.
- 33. 5. Cogroup all the things join (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,( A , B ))] leftJoin (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,( A ,Option[B]))] rightJoin (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,(Option[A], B) )] outerJoin (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,(Option[A],Option[B]))] cogroup (left:RDD[(K,A)],right:RDD[(K,B)]):RDD[(K,( Seq[A], Seq[B]))] groupBy (rdd:RDD[(K,A)]):RDD[(K,Seq[A])] On cogroup and groupBy, for a given key:K, there is only one unique row with that key in the output dataset.
- 34. 5. Cogroup all the things
- 35. 5. Cogroup all the things {case (k,(s1,s2)) => (k,(s1.map(fA).filter(pA) ,s2.map(fB).filter(pB)))} CHECKPOINT
- 36. 5. Cogroup all the things 3k LoC 30 minutes to run (non- blocking) 15 LoC 11 hours to run (blocking)
- 37. 5. Cogroup all the things What about tests? Cogrouping allows us to have “ScalaChecks-like” tests, by minimising examples. Test workflow : Write a predicate to isolate the bug. Get the minimal cogrouped row ouput the row in test resources. Reproduce the bug. Write tests and fix code.
- 38. 6. Inline data quality
- 39. 6. Inline data quality Data quality improves resilience to bad data. But data quality concerns come second.
- 40. 6. Inline data quality case class FixeVisiteur( devicetype: String, isrobot: Boolean, recherche_visitorid: String, sessions: List[FixeSession] ) { def recherches: List[FixeRecherche] = sessions.flatMap(_.recherches) } object FixeVisiteur { @autoBuildResult def build( devicetype: Result[String], isrobot: Result[Boolean], recherche_visitorid: Result[String], sessions: Result[List[FixeSession]] ): Result[FixeVisiteur] = MacroMarker.generated_applicative } Example :
- 41. 6. Inline data quality case class Annotation( anchor: Anchor, message: String, badData: Option[String], expectedData: List[String], remainingData: List[String], level: String @@ AnnotationLevel, annotationId: Option[AnnotationId], stage: String ) case class Anchor(path: String @@ AnchorPath, typeName: String)
- 42. 6. Inline data quality Message : EMPTY_STRING MULTIPLE_VALUES NOT_IN_ENUM PARSE_ERROR ______________ Levels : WARNING ERROR CRITICAL
- 43. 6. Inline data quality Data quality is available within the output rows. case class HVisiteur( visitorId: String, atVisitorId: Option[String], isRobot: Boolean, typeClient: String @@ TypeClient, typeSupport: String @@ TypeSupport, typeSource: String @@ TypeSource, hVisiteurPlus: Option[HVisiteurPlus], sessions: List[HSession], annotations: Seq[HAnnotation] )
- 44. 6. Inline data quality (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> lib_source, message -> NOT_IN_ENUM, type -> String @@ LibSource, level -> WARNING)),657366) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> analyseInfos.analyse_typequoi, message -> EMPTY_STRING, type -> String @@ TypeRecherche, level -> WARNING)),201930) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> isrobot, message -> MULTIPLE_VALUE, type -> String, level -> WARNING)),15) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> rechercheInfos, message -> MULTIPLE_VALUE, type -> String, level -> WARNING)),566973) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> reponseInfos.reponse_nbblocs, message -> MULTIPLE_VALUE, type -> String, level -> WARNING)),571313) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> requeteInfos.requete_typerequete, message -> MULTIPLE_VALUE, type -> String, level -> WARNING)),315297) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> analyseInfos.analyse_typequoi_sec, message -> EMPTY_STRING, type -> String @@ TypeRecherche, level -> WARNING)),201930) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> typereponse, message -> EMPTY_STRING, type -> String @@ TypeReponse, level -> WARNING)),323614) (KeyPerformanceIndicator(Annotation,annotation,Map(stage -> MappingFixe, path -> grp_source, message -> MULTIPLE_VALUE, type -> String, level -> WARNING)),94)
- 45. 6. Inline data quality https://github.com/ahoy-jon/autoBuild (presented in october 2015) There are opportunities to make those approaches more “precepte-like”. (DAG of workflow, provenance of every fields, structure tags)
- 46. 7. Create real programs
- 47. 7. Create real programs Most pipelines are designed as “Stateless” computation. They require no state (good) Or Infer the current state based on filesystem’ states (bad).
- 48. 7. Create real programs Solution : Allow pipelines to access a commit log to read about past execution and to push data for future execution.
- 49. 7. Create real programs In progress: project codename Kerguelen Multi level abstractions / commit log backed / api for jobs. Allow creation of jobs that have different concern level. Level 1 : name resolving Level 2 : smart intermediaries (schema capture, stats, delta, …) Level 3 : smart high level scheduler (replay, load management, coherence) Level 4 : “code as data” (=> continuous delivery, auto QA, auto mep)
- 50. Conclusion
Editor's Notes
- #37: ~15 lines of code