Scavenger

Machine Learning methods and algorithms are often highly modular in the sense that they rely on a large number of subalgorithms that are in principle interchangeable. For example, it is often possible to use various kinds of pre- and post-processing and various base classifiers or regressors as components of the same modular approach. Scavenger is a framework, that allows evaluating whole families of conceptually similar algorithms efficiently. The algorithms are represented as compositions, couplings and products of atomic subalgorithms. This allows partial results to be cached and shared between different instances of a modular algorithm, so that potentially expensive partial results need not be recomputed multiple times. Furthermore, Scavenger deals with issues of the parallel execution, load balancing, and with the backup of partial results for the case of implementation or runtime errors.

Build

Scavenger is in Maven central, include the following dependency in your pom.xml:

<dependency>	
    <groupId>org.kramerlab</groupId>
    <artifactId>scavenger</artifactId>
    <version>2.1</version>
</dependency>

if you do not use Maven in your project, you can use

mvn clean install

to build the jar files.

Run

Depending on your projects configuration, you can run the seed via:

java -cp <jar-files> scavenger.app.SeedMain

or, using

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>exec-maven-plugin</artifactId>
  <version>1.1</version>
  <executions><execution>
  </execution></executions>
</plugin>

mvn exec:java -Dexec.mainClass="scavenger.app.SeedMain" -Dconfig.file=<configFile>

The worker is in the class:

mvn exec:java -Dexec.mainClass="scavenger.app.WorkerMain" -Dakka.remote.netty.tcp.hostname=<host> -Dakka.remote.netty.tcp.port=<port> -Dconfig.file=<configFile>

is any arbitrary port that the worker uses to communicate with the seed.

For the basic demo run:

mvn exec:java -Dexec.mainClass="scavenger.demo.Demo" -Dakka.remote.netty.tcp.hostname=<host> -Dakka.remote.netty.tcp.port=<port>  -Dconfig.file=<configFile>

Examples

We have a seperate demo git repository with a few examples at https://github.com/joergwicker/scavenger_demo (note that the README file uses sbt, but Scavenger uses Maven).

Cite

If you use Scavenger, please cite:

@inproceedings{tyukin2015scavenger,
title = {Scavenger - A Framework for the Efficient Evaluation of Dynamic and Modular Algorithms},
author = { Andrey Tyukin and Stefan Kramer and Jörg Wicker},
editor = {Albert Bifet and Michael May and Bianca Zadrozny and Ricard Gavalda and Dino Pedreschi and Jaime Cardoso and Myra Spiliopoulou},
url = {http://dx.doi.org/10.1007/978-3-319-23461-8_40},
doi = {10.1007/978-3-319-23461-8_40},
isbn = {978-3-319-23460-1},
year = {2015},
date = {2015-09-07},
booktitle = {Machine Learning and Knowledge Discovery in Databases},
volume = {9286},
pages = {325-328},
publisher = {Springer International Publishing},
series = {Lecture Notes in Computer Science}
}

Mixed Java and Scala Classes

If you have a maven project with java and scala classes, this seems to work:

   <dependency>
      <groupId>org.scala-lang</groupId>
    <artifactId>scala-library</artifactId>
      ...

  <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.scala-tools</groupId>
                <artifactId>maven-scala-plugin</artifactId>
                <version>2.15.2</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
            </plugin>
        </plugins>
    </pluginManagement>
    <plugins>
        <plugin>
            <groupId>org.scala-tools</groupId>
            <artifactId>maven-scala-plugin</artifactId>
            <executions>
                <execution>
                    <id>scala-compile-first</id>
                    <phase>process-resources</phase>
                    <goals>
                        <goal>add-source</goal>
                        <goal>compile</goal>
                    </goals>
                </execution>
                <execution>
                    <id>scala-test-compile</id>
                    <phase>process-test-resources</phase>
                    <goals>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <executions>
                <execution>
                    <phase>compile</phase>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>