_posts/2014-01-12-0.4-migration-guide.md

---
layout: post
title:  'Stratosphere Version 0.4 Migration Guide'
date:   2014-01-12 19:57:18
categories: news
---

This guide is intended to help users of previous Stratosphere versions to migrate their programs to the new API of v0.4.

Version `0.4-rc1`, `0.4` and all newer versions have the new API. If you want to have the most recent version before the code change, please set the version to `0.4-alpha.3-SNAPSHOT`. (Note that the `0.4-alpha` versions are only available in the snapshot repository).

#### Maven Dependencies
Since we also reorganized the Maven project structure, existing programs need to update the Maven dependencies to `stratosphere-java` (and `stratosphere-clients`, for examples and executors).

The typical set of Maven dependencies for Stratosphere Java programs is:

```diff
       <groupId>eu.stratosphere</groupId>
-      <artifactId>pact-common</artifactId>
-      <version>0.4-SNAPSHOT</version>
+      <artifactId>stratosphere-java</artifactId>
+      <version>0.4</version>

-      <artifactId>pact-clients</artifactId>
-      <version>0.4-SNAPSHOT</version>
+      <artifactId>stratosphere-clients</artifactId>
+      <version>0.4</version>
```


#### Renamed classes

We renamed many of the most commonly used classes to make their names more intuitive:

<table class="table table-striped">
  <thead>
  	<tr>
  	<th>Old Name (before <code>0.4</code>)</th>
  	<th>New Name (<code>0.4</code> and after)</th>
  </tr>
  </thead>
 	<tbody>
	  <tr>
	  	<td>Contract</td>
	  	<td>Operator</td>
	  </tr>
	  <tr>
	  	<td>MatchContract</td>
	  	<td>JoinOperator</td>
	  </tr>

	  	  <tr>
	  	<td>[Map, Reduce, ...]Stub</td>
	  	<td>[Map, Reduce, ...]Function</td>
	  </tr>
	  	  <tr>
	  	<td>MatchStub</td>
	  	<td>JoinFunction</td>
	  </tr>
	  	  <tr>
	  	<td>Pact[Integer, Double, ...]</td>
	  	<td>IntValue, DoubleValue, ...</td>
	  </tr>	  
	  <tr>
	  	<td>PactRecord</td>
	  	<td>Record</td>
	  </tr>
	  	  <tr>
	  	<td>PlanAssembler</td>
	  	<td>Program</td>
	  </tr>
	  	  <tr>
	  	<td>PlanAssemblerDescription</td>
	  	<td>ProgramDescription</td>
	  </tr>
	  	  <tr>
	  	<td>RecordOutputFormat</td>
	  	<td>CsvOutputFormat</td>
	  </tr>
	</tbody>
</table>


Package names have been adapted as well.
For a complete overview of the renamings, have a look at [issue #257 on GitHub](https://github.com/stratosphere/stratosphere/issues/257).


We suggest for Eclipse user adjust the programs as follows: Delete all old Stratosphere imports, then rename the the classes (`PactRecord` to `Record` and so on). Finally, use the “Organize Imports” function (`CTRL+SHIFT+O`) to choose the right imports. The names should be unique so always pick the classes that are in the `eu.stratosphere` package.

Please contact us in the comments below, on the mailing list or on GitHub if you have any issues migrating to the latest Stratosphere release.