Download - Apache Sqoop: Unlocking Hadoop for Your Relational Database

Unlocking Hadoop for Your Rela4onal DB

Kathleen Ting | @kate_ting Technical Account Manager, Cloudera | Sqoop PMC Member Hadoop User Group UK 10 April 2014

Who Am I?

•  Started 3 yr ago as 1st Cloudera Support Eng •  Now manages Cloudera’s 2 largest customers

•  Sqoop CommiJer, PMC Member •  Co-‐Author of the Apache Sqoop Cookbook

What is Sqoop?

•  Apache Top-‐Level Project •  SQl to hadOOP •  Tool to transfer data from rela4onal databases

•  Teradata, MySQL, PostgreSQL, Oracle, Netezza

•  To/From Hadoop ecosystem •  HDFS (text, sequence file), Hive, HBase, Avro

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Why Sqoop?

•  Efficient/Controlled resource u4liza4on •  Concurrent connec4ons, Time of opera4on

•  Datatype mapping and conversion •  Automa4c, and User override

• Metadata propaga4on •  Sqoop Record •  Hive Metastore •  Avro

Agenda

Sqoop 1 •  Sqoop 1 Architecture •  Sqoop 1 Command Line •  Sqoop 1 Examples •  Sqoop 1 Challenges •  Troubleshoo4ng Sqoop 1 •  Common Sqoop 1 Issues

•  Protec4ng Your Password •  Sqoop Works on CLI Not in Oozie •  Choosing Proper Connector •  Overriding Type Mapping

Sqoop 2 •  Sqoop 2 Architecture •  Sqoop 2 Design Goals •  Sqoop 2 UI in Hue Resources

Sqoop 1 Architecture

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Sqoop 1 Command Line

sqoop TOOL PROPS ARG [-- EXTRA] •  TOOL: import, export •  PROPS

•  Hadoop (java) proper4es •  -Dwhatever.whenever=yes

•  ARG •  Generic SQOOP arguments •  --table, --connect, ...

•  EXTRA •  connector specific •  --schema (PostgreSQL and Microsoa SQL Server)

Sqoop 1 Example

sqoop import \ --connect jdbc:mysql://mysql.example.com/sqoop \ --username sqoop --password sqoop \ --table cities

sqoop export \ --connect jdbc:mysql://mysql.example.com/sqoop \ --username sqoop --password sqoop \ --table cities \ --export-dir /temp/cities

Sqoop 1 Challenges

•  Cryp4c, contextual command line arguments •  Security concerns •  Type mapping is not clearly defined •  Client needs access to Hadoop binaries/configura4on and database

•  JDBC model is enforced

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Troubleshoo4ng Sqoop 1

•  Versions: Sqoop, Hadoop, OS, JDBC •  Console log aaer running with the --verbose flag

•  Capture the en4re output via sqoop import … &> sqoop.log •  En4re Sqoop command including the op4ons-‐file if applicable •  Expected output and actual output •  Table defini4on •  Small input data set that triggers the problem

•  Especially with export, malformed data is oaen the culprit •  Hadoop task logs

•  Oaen the task logs contain further informa4on describing the problem •  Permissions on input files

Troubleshoo4ng Sqoop 1

Imported table has more rows than source table? •  Data contains char used as Hive’s delimiters

•  Clean up data •  --hive-drop-import-delims

•  Removes \n, \t, and \01 char

•  --hive-delims-replacement “SPECIAL” •  Replaces \n, \t, and \01 char with string SPECIAL

•  Not restricted to Hive -‐ any import job using text files •  Ensure output files have one line per imported row

Agenda




Common Sqoop 1 Issues


Protec4ng Your Password

sqoop import \ --connect jdbc:mysql://mysql.example.com/sqoop \ --username sqoop \ --table cities \ -P

sqoop import \ --connect jdbc:mysql://mysql.example.com/sqoop \ --username sqoop \ --table cities \ --password-file my-sqoop-password

Sqoop Works on CLI Not in Oozie

Character parameter '|' has multiple characters; only the first will be used.

Got error creating database manager: java.io.IOException:

No manager for connect string: "jdbc:teradata...”

Sqoop Works on CLI Not in Oozie

sqoop import --password "spEci@l\$" \ –connect 'jdbc:x:/yyy;db=sqoop’

•  Remove all escaping that you’ve added for the shell •  Use <arg> vs <command> tags as content is considered to be one parameter

•  Put all -‐D parameters into configura4on sec4on •  Install driver into workflow’s lib/ directory or shared ac4on library /user/oozie/share/lib/sqoop/

Choosing Proper Connector

•  JDBC driver is dependency for all three connectors

•  Sqoop automa4cally chooses most op4mal connector (OraOoop, built-‐in,

Generic JDBC Connector) •  Or explicitly chose: --connection-manager com.quest.oraoop.OraOopConnManager

Overriding Type Mapping

-‐-‐map-‐column-‐java parameter •  comma separated list of key-‐value pairs

•  key = exact column name •  value = target Java type

sqoop import \

--map-column-java \

c1=Float,c2=String,c3=String ...

Agenda




Sqoop 2 Architecture

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Sqoop 2 Design Goals

•  Security and Separa4on of Concerns •  Role based access and use

•  Ease of extension •  No low-‐level Hadoop knowledge needed •  No func4onal overlap between Connectors

•  Ease of Use •  Uniform func4onality •  Domain specific interac4ons

Sqoop 2 UI in Hue

•  Troubleshoo4ng •  sqoop.log file is located in @LOGDIR@ and the rest should be in server/logs/*

•  Look for catalina.out, catalina.log, localhost-‐*.log

Agenda




Resources

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Sqoop 2 http://archive-primary.cloudera.com/cdh5/cdh/5/sqoop2/

Sqoop 1