TAGME V1.1 - HOW TO

COPYRIGHT

Copyright 2014 - A3 lab (Dipartimento di Informatica, Università di Pisa)

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Please note that some of TAGME's dependencies, are licensed under the terms of the GPLv3 or LGPLv3 licenses. Please check license and copying information for all dependency libraries (see below).

AUTHORS' NOTE

Even if the live demo of TAGME that is available at https://services.d4science.org/web/tagme/documentation has been queried more than 400 millions of times since its introduction in 2011, and has been able to handle thousands of queries per minute without any issue (hence proving a certain stability), this code has still to be considered an academic prototype: it is the result of several refinement iterations and multiple researchers have put their hands on the code with a "trial and error" approach.

For this reason, it is not meant be used in production environments or critical applications. As stated in the license, the software is distributed as is, without warranties or conditions of any kind.

If you are using this software for your researches and you are going to publish results based on TAGME annotation process, please add this citation to your paper:

Paolo Ferragina, Ugo Scaiella: Fast and Accurate Annotation of Short Texts with Wikipedia Pages. IEEE Software 29(1): 70-75 (2012)

For more information on TagMe and some of its applications, please visit: http://acube.di.unipi.it/tagme/

REQUIREMENTS

TAGME requires Java 6 to compile, run and process Wikipedia data. Apache Ant tool ( http://ant.apache.org/ ) is required to build the code, download and to process Wikipedia data.

Minimum RAM required to run TAGME is about 2 gigabytes. More resources are required to index Wikipedia data. See below for further details.

DEPENDENCIES

The following is the directory structure required to build the code:

./
  src/
  lib/
  ext_lib/
  preproc_lib/

./src/ directory contains TAGME's source files, provided within this package.

The following artifacts are required to build and run TAGME. Standard Maven notation has been used to identify them: <groupId>:<artifactId>:<version>. You can download those libraries from http://search.maven.org, or use the following ant task

$ ant get-deps

The directory ./lib/ must contain all libraries required to compile and run TAGME:

com.martiansoftware:jsap:2.1.jar
commons-beanutils:commons-beanutils:1.8.3
commons-codec:commons-codec:1.5
commons-collections:commons-collections:3.2.1
commons-configuration:commons-configuration:1.7
commons-io:commons-io:2.0.1
commons-lang:commons-lang:2.6
commons-logging:commons-logging:1.1.1
it.unimi.dsi:dsiutils:2.0.4
it.unimi.dsi:fastutil:6.4.1
it.unimi.dsi:sux4j:3.0.2
it.unimi.dsi:webgraph:3.0.4
org.apache.commons:commons-digester3:3.0
org.apache.lucene:lucene-core:3.4.0
org.json:json:20131018
log4j:log4j:1.2.16
snowball (provided within the package)

The directory ./ext_lib/ must contain all libraries required to compile TAGME, but are not required when running it:

org.apache.tomcat:catalina:6.0.37
javax.servlet:servlet-api:2.4

The directory ./preproc_lib/ must contain all libraries required to during pre-processing of Wikipedia data:

javax.mail:mailapi:1.4.3
com.sun.mail:smtp:1.4.4

BUILDING

Ant build file is provided within the package. You can run the command from the base directory

$ ant jar

to build TAGME. A jar file named ./tagme.jar will be created inside the base directory.

CONFIGURATION

The configuration file has to be provided using JVM system properties from command line

-Dtagme.config=<path_to_config_file>

A sample configuration is provided within this package, look at the file ./config.sample.xml. Also, the file ./config.template.xml contains a model of the configuration that can be used as a reference like an XML DTD.

Finally, a log4j configuration file is provided, look at ./log4j.xml.

FAST VS LIGHT MODE

TAGME supports for two execution modes: the 'fast' one that pre-load several data into memory and needs for several GBs of heap space, and the 'light' one that requires less memory but is also slower.

In order to run TAGME in fast mode, two parameters must be set as follow (using XPath-like notation):

/tagme/settings(parsing)/data = TERNARY_TRIE
/tagme/settings(annotation)/relatedness = MATRIX

Using the above settings, you need for approximatively 16G of RAM to use English Wikipedia and 6G of RAM to use Italian. The JVM Heap Space has to be set accordingly, using JVM properties. Eg, to use both Italian and English (about 24G ) you must include this to java command line: -Xmx24G. Alternatively, you can reduce the memory consumption, removing those two settings. In this case, 2G of RAM are enough to run both Italian and English. Obviously, annotation process will be less faster.

RUNNING

Before running TAGME you have to process Wikipedia sources in order to create data that is needed at runtime. This process may take several hours and it is detailed in the next sections.

Once the data is available, you can run TAGME. First of all, the initialization process has to be executed, by calling the method

it.acubelab.tagme.config.TagmeConfig.init();

This will read the configuration, set the logging (logging framework is Log4j) and load data structures.

Main class for annotating texts is it.acubelab.tagme.wrapper.Annotator. The constructor accepts a String identifying a language code (can be "de", "en", "es", "fr" or "it") and provides few methods to get annotations from a text. Namely the method

List<Annotation> getAnnotationList(String to_annot)

can be used to annotate the string "to_annot". A list of Annotation objects is returned.

Check the source code and JavaDoc of it.acubelab.tagme.wrapper.Annotator class for further details.

CODE SAMPLES

A couple of code samples are provided within this package in the samples folder:

./
  samples/
    Example1.java
    Example2.java

Both classes contain a simple main method that can be used to understand the main TAGME's objects, how to access data structures, how to annotate texts and get the results.

You can compile them providing all dependencies and TAGME classes in the classpath of java compiler (you must first compile TAGME using ant script as detailed above)

$ javac -cp lib/*:ext_lib/*:bin/ samples/Example1.java

then you can run it using:

$ java -cp lib/*:ext_lib/*:bin/:samples/ \
        -Xmx16G -Dtagme.config=<path to tagme config> \
        Example1

It may take some time to load into memory all required data, based on the configuration you have selected (see details above).

TAGME'S REPOSITORY

TAGME requires several pre-processed data structures for annotating. Those datasets are build from Wikipedia source files (see below) and are stored within a directory that is called TAGME repository. The absolute path of this directory has to be specified in the TAGME's configuration file. See the configuration sample for further details.

STOPWORD REPOSITORY

A set of files containing stopword lists is provided within this package (look at ./stopwords/ directory). The directory containing this set of file is the stopword repository and the absolute path has to be specified in the TAGME's configuration file. See the configuration sample for further details.

INDEXING

TAGME repository can be built from Wikipedia dumps provided by the Wikimedia Foundation at http://dumps.wikimedia.org/ . Additionally, information about article categories are extracted from a DBpedia dataset, that can be found at http://downloads.dbpedia.org/

TAGME repository has the following structure:

<repository root>/
  de/
    source/
    ...
  en/
    source/
    ...
  es/
    source/
    ...
  fr/
    source/
    ...
  it/
    source/
    ...
  wikipatterns.properties

The wikipatterns.properties file is the one that is provided within this package and must be copied in the base directory of the repository.

An Ant task can be used to download all required datasets from Wikipedia and DBpedia:

$ ant get-source -Dlang=... -Ddd=... -Ddbpedia=... -Dtargetdir=...

where:

• lang can be de (German), en (English), es (Spanish), fr (French) or it (Italian).
• dd is the version of the Wikipedia dump in the format YYYYMMDD (the date of the snapshot). See http://dumps.wikimedia.org/backup-index.html for further details.
• dbpedia is the version of DBpedia, in the format X.Y. See http://downloads.dbpedia.org/ for additional details.
• targetdir is the directory where files will be stored, ie <repository root>/de/source for German, <repository root>/en/source for English, and so on.

This task downloads and extracts Wikipedia and DBpedia data. Note that for English Wikipedia, this requires about 90G of disk space. Additionally, the process generates several datasets and to complete the indexing you should need for about 180 GB.

When all data has been downloaded, another Ant task can be executed to index Wikipedia/DBpedia data.

$ ant index.all -Dconfig.file=... -Dmem=... -Dmailto=... -Dlang=

where:

• lang can be de (German), en (English), es (Spanish), fr (French) or it (Italian).
• config.file is the absolute path to the TAGME config file, where the repository path, log4j configuration file path and other parameters are specified.
• mem is the amount of JVM heap space to allocate for the process (basically you need for the same amount of memory that is required to run TAGME), for example -Dmem=24G.
• mailto (optional) the email address where a notification of the end of the process will be sent. An SMTP server must be installed in the machine.

This task creates all data structures, also the ones used in fast mode, so the task itself requires a lot of memory (see above). If you need to generate data just to run in 'light mode', you can execute this Ant task:

$ ant index.light -Dconfig.file=... -Dmem=... -Dmailto=... -Dlang=

Indexing may take several hours (about 40 hours for English wikipedia), so it is recommended running it with a tool like screen or tmux.

If you are using the log4j configuration file attached to this package, the output of the process is redirect to the standard output, that Ant redirects to a file that will be create for each task run. You can find this file in ./logs/ directory. Ant task takes care to generate a unique a file name for each task run.

Disclaimer by Aurélien Géron

I am not the original author of this project. I contacted Paolo Ferragina, who provided me with this code under the Apache 2.0 License, and kindly authorized me to publish it on GitHub. I made a few minor modifications before the first commit:

• Renamed LICENSE.txt to LICENSE, and README.txt to README.md, and updated build.xml accordingly.
• Made purely cosmetic changes to this README.md file and added this final section.
• Added the .gitignore file.

Feel free to clone & submit pull requests.