From oracle to hadoop with Sqoop and other tools
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This document discusses tools for transferring data between relational databases and Hadoop, focusing on Apache Sqoop. It describes how Sqoop was optimized for Oracle imports and exports, reducing database load by up to 99% and improving performance by 5-20x. It also outlines the goals of Sqoop 2 to improve usability, security, and extensibility through a REST API and by separating responsibilities.
From oracle to hadoop with Sqoop and other tools
- 1. From Oracle to Hadoop: Unlocking Hadoop for Your RDBMS with Apache Sqoop and Other Tools Guy Harrison, David Robson, Kate Ting {guy.harrison, david.robson}@software.dell.com, [email protected] October 16, 2014
- 2. About Guy, David, & Kate Guy Harrison @guyharrison - Executive Director of R&D @ Dell - Author of Oracle Performance Survival Guide & MySQL Stored Procedure Programming David Robson @DavidR021 - Principal Technologist @ Dell - Sqoop Committer, Lead on Toad for Hadoop & OraOop Kate Ting @kate_ting - Technical Account Mgr @ Cloudera - Sqoop Committer/PMC, Co-author of Apache Sqoop Cookbook
- 6. RDBMS and Hadoop The relational database reigned supreme for more than two decades Hadoop and other non-relational tools have overthrown that hegemony We are unlikely to return to a “one size fits all” model based on Hadoop - Though some will try For the foreseeable future, enterprise information architectures will include relational and non-relational stores
- 7. Scenarios 1. We need to access RDBMS to make sense of Hadoop data Analytic output YARN/ MR1 HDFS Weblogs Products RDBMS Flume SQOOP
- 8. Scenarios 1. Reference data is in the RDBMS 2. We want to run analysis outside of the RDBMS Analytic output HDFS Products RDBMS SQOOP YARN/ MR1 Sales SQOOP
- 9. Scenarios 1. Reference data is in the RDBMS 2. We want to run analysis outside of the RDBMS 3. Feeding YARN/MR output into RDBMS Analytic output HDFS Weblogs Weblog Summary RDBMS Flume SQOOP YARN/ MR1
- 10. Scenarios 1. We need to access RDBMS to make sense of Hadoop data 2. We want to use Hadoop to analyse RDBMS data 3. Hadoop output belongs in RDBMS Data warehouse 4. We archive old RDBMS data to Hadoop HDFS BI platform Sales RDBMS SQOOP HQL Old Sales SQL
- 11. SQOOP SQOOP was created in 2009 by Aaron Kimball as a means of moving data between SQL databases and Hadoop It provided a generic implementation for moving data It also provided a framework for implementing database specific optimized connectors
- 12. How SQOOP works (import) Hive Table HDFS Table Metadata Table Data RDBMS Hive DDL Table.java SQOOP Map Task FileOutputFormat DataDrivenDBInputFormat Map Task DataDrivenDBInputFormat FileOutputFormat HDFS files
- 13. SQOOP & Oracle
- 14. SQOOP issues with Oracle SQOOP uses primary key ranges to divide up data between mappers However, the deletes hit older key values harder, making key ranges unbalanced. Data is almost never arranged on disk in key order so index scans collide on disk Load is unbalanced, and IO block requests >> blocks in the table. ORACLE TABLE on DISK ID > 0 and ID < MAX/2 MAPPER ORACLE SESSION RANGE SCAN Index block Index block ID > MAX/2 MAPPER ORACLE SESSION RANGE SCAN Index block Index block Index block Index block
- 15. Other problems Oracle might run each mapper using a full scan – clobbering the database Oracle might run each mapper in parallel – clobbering the database Sqoop may clobber the database cache 1800 1600 1400 1200 1000 800 600 400 200 0 0 2 4 6 8 10 12 14 16 18 Elasped time (s) 7000 6000 5000 4000 3000 2000 1000 Database load 0 Number of mappers 0 4 8 12 16 20 24 Database Time (s) Number of mappers
- 16. High speed connector design Partition data based on physical storage By-pass Oracle buffering By-pass Oracle parallelism Do not require or use indexes Never read the same data block more than once Support Oracle datatypes ORACLE TABLE HDFS HADOOP MAPPER ORACLE SESSION HADOOP MAPPER ORACLE SESSION HADOOP MAPPER ORACLE SESSION
- 17. Imports (Oracle->Hadoop) Uses Oracle block/extent map to equally divide IO Uses Oracle direct path (non-buffered) IO for all reads Round-robin, sequential or random allocation All mappers get an equal number of blocks & no block is read twice If table is partitioned, each mapper can work on a separate partition – results in partitioned output ORACLE TABLE HDFS HADOOP MAPPER ORACLE SESSION HADOOP MAPPER ORACLE SESSION HADOOP MAPPER ORACLE SESSION
- 18. Exports (Hadoop-> Oracle) Optionally leverages Oracle partitions and temporary tables for parallel writes Performs MERGE into Oracle table (Updates existing rows, inserts new rows) Optionally use oracle NOLOGGING (faster but unrecoverable) ORACLE TABLE HDFS HADOOP MAPPER ORACLE SESSION HADOOP MAPPER ORACLE SESSION HADOOP MAPPER ORACLE SESSION
- 19. Import – Oracle to Hadoop When data is unclustered (randomly distributed by PK), old SQOOP scales poorly Clustered data shows better scalability but is still much slower than the direct approach. New SQOOP outperforms 5-20 times typically We’ve seen limiting factor as: - Data IO bandwidth, or - Network out of DB, or - Hadoop CPU 1600 1400 1200 1000 800 600 400 200 0 0 5 10 15 20 25 30 35 Elapsed time (s) Number of mappers direct=false - unclustered Data direct=false clustered data direct=true
- 20. Import - Database overhead As you increase mappers in old sqoop, database load increases rapidly - (sometimes non-linear) In new Sqoop, queuing occurs only after IO bandwidth is exceeded 3000 2500 2000 1500 1000 500 0 0 4 8 12 16 20 24 DB time (minutes) Number of mappers Sqoop Direct
- 21. Export – Oracle to Hadoop On Export, old SQOOP would hit database writer bottleneck early on and fail to parallelize. New SQOOP uses partitioning and direct path inserts. Typically bottlenecks on write IO on Oracle side 120 100 80 60 40 20 0 0 4 8 12 16 20 24 Elapsed time (minutes) Number of mappers Sqoop Direct
- 22. Reduction in database load 45% reduction in DB CPU 83% reduction in elapsed time 90% reduction in total database time 99.9% reduction in database IO 8 node Hadoop cluster, 1B rows, 310GB 55.31 83.45 90.59 99.98 99.28 0 20 40 60 80 100 IO time IO requests DB time Elapsed time CPU time % reduction
- 23. Replication No matter how fast we make SQOOP, it’s a drag to have to run a SQOOP job before every Hadoop job. Replicating data into Hadoop cuts down on SQOOP overhead on both sides and avoids stale data. Shareplex® for Oracle and Hadoop
- 24. Sqoop 1.4.5 Summary Sqoop 1.4.5 without –direct Sqoop 1.4.5 with --direct Minimal privileges required Access to DBA views required Works on most object types: e.g. IOT 5x-20x faster performance on tables Favors Sqoop terminology Favors Oracle terminology Database load increases non-linearly Up to 99% reduction in database IO
- 25. Future of SQOOP
- 26. Sqoop 1 Import Architecture sqoop import --connect jdbc:mysql://mysql.example.com/sqoop --username sqoop --password sqoop --table cities
- 27. Sqoop 1 Export Architecture sqoop export --connect jdbc:mysql://mysql.example.com/sqoop --username sqoop --password sqoop --table cities --export-dir /temp/cities
- 28. Sqoop 1 Challenges Concerns with usability - Cryptic, contextual command line arguments Concerns with security - Client access to Hadoop bin/config, DB Concerns with extensibility - Connectors tightly coupled with data format
- 29. Sqoop 2 Design Goals Ease of use - REST API and Java API Ease of security - Separation of responsibilities Ease of extensibility - Connector SDK, focus on pluggability
- 30. Ease of Use Sqoop 1 Sqoop 2 sqoop import - Dmapred.child.java.opts="Djava.security.egd=file:///dev/ura ndom“ -Ddfs.replication=1 -Dmapred.map.tasks.speculative.execution=false --num-mappers 4 --hive-import --hive-table CUSTOMERS --create-hive-table --connect jdbc:oracle:thin:@//localhost:1521/g12c --username OPSG --password opsg --table OPSG.CUSTOMERS --target-dir CUSTOMERS.CUSTOMERS
- 31. Ease of Security Sqoop 1 Sqoop 2 sqoop import - Dmapred.child.java.opts="Djava.security.egd=file:///dev/ura ndom“ -Ddfs.replication=1 -Dmapred.map.tasks.speculative.execution=false --num-mappers 4 --hive-import --hive-table CUSTOMERS --create-hive-table --connect jdbc:oracle:thin:@//localhost:1521/g12c --username OPSG --password opsg --table OPSG.CUSTOMERS --target-dir CUSTOMERS.CUSTOMERS • Role-based access to connection objects • Prevents misuse and abuse • Administrators create, edit, delete • Operators use
- 32. Ease of Extensibility Sqoop 1 Sqoop 2 Tight Coupling • Connectors fetch and store data from db • Framework handles serialization, format conversion, integration
- 33. Takeaway Apache Sqoop - Bulk data transfer tool between external structured datastores and Hadoop Sqoop 1.4.5 now with a --direct parameter option for Oracle - 5x-20x performance improvement on Oracle table imports Sqoop 2 - Ease of use, security, extensibility
- 34. Questions? Guy Harrison @guyharrison David Robson @DavidR021 Kate Ting @kate_ting Visit Dell at Booth #102 Visit Cloudera at Booth #305 Book Signing: Today @ 3:15pm Office Hours: Tomorrow @ 11am
Editor's Notes
- #4: When you think about Dell you probably think about laptops
- #5: Or servers that might run databases or a Hadoop cluster, but you probably don't think of Dell as having expertise in either Oracle or Hadoop
- #6: But actually Dell now has a billion-dollar software arm which includes the world's number one independent database tool – toad – used by millions of users and supporting almost every data platform
- #7: Guy to improve diagram