Heritrix-Cassandra

A library for writing Heritrix 3 output directly to Cassandra as records.

Getting Started

1. Visit http://github.com/openplaces/heritrix-cassandra/tree/master/releases/ and obtain a release of heritrix-cassandra that corresponds to the versions of Heritrix and Cassandra you are running. Consult the "Releases" section for more information.
2. Copy the heritrix-cassandra-{version}.jar file into your Heritrix install's lib folder.

3. Copy the following list of files from your Cassandra lib folder into your Heritrix install's lib folder:

   • apache-cassandra-*.jar
   • libthrift-*.jar
   • log4j-*.jar
   • slf4j-api-*.jar
   • slf4j-log4j*.jar

4. Modify your Heritrix job configuration to use the heritrix-cassandra writer

crawler-beans.cxml:

<!-- DISPOSITION CHAIN -->
<bean id="cassandraParameters" class="org.archive.io.cassandra.CassandraParameters">
  <!-- "seeds" and "keyspace" are required, while port defaults to 9160 -->

  <!-- Pass a comma-separated list of servers to Cassandra here -->
  <property name="seeds" value="localhost,127.0.0.1" />

  <!-- This is the thrift port -->
  <property name="port" value="9160" />

  <!-- Your application specific keyspace -->
  <property name="keyspace" value="MyApplication" />

  <!-- Change the crawlColumnFamily from its default value of 'crawl' -->
  <property name="crawlColumnFamily" value="crawled_pages" />

  <!-- Other parameters are overridden similarly and a full list is provided below -->
</bean>

<bean id="cassandraWriterProcessor" class="org.archive.modules.writer.CassandraWriterProcessor">
  <property name="cassandraParameters">
    <!-- Referencing the named bean we defined above -->
    <ref bean="cassandraParameters" />
  </property>
</bean>

[...]

<bean id="dispositionProcessors" class="org.archive.modules.DispositionChain">
  <property name="processors">
    <list>
      <!-- write to aggregate archival files... -->
      <ref bean="cassandraWriterProcessor"/>
      <!-- other references -->
    </list>
  </property>
</bean>

org.archive.io.cassandra.CassandraParameters

Parameter	Default Value	Description
seeds	(none)	Comma-separated list of Cassandra servers (can be a list of any nodes in your cluster).
port	9160	The Thrift port.
keyspace	(none)	The name of your Cassandra keyspace.
crawlColumnFamily	crawl	Name of the column family to use.
encodingScheme	UTF-8	Encoding scheme you're using.
framedTransport	false	Whether to used Thrift's Framed Transport
contentPrefix	content	Name of the logical prefix used to save the raw content to. If contentColumnName is redefined, then this prefix will be overridden and no longer used.
contentColumnName	raw_data	Name of the column used to save the raw content to.
headersColumnName	headers	Name of the column used to save the headers to (if separateHeaders is set to true).
curiPrefix	curi	Name of the logical prefix used to store the metadata related to the crawl. If any of the following parameters are redefined, then this prefix will be overridden and no longer used with it.
ipColumnName	ip	Name of the column used to save the resolved ip to.
pathFromSeedColumnName	path-from-seed	Name of the column used to save the path from the seed to.
isSeedColumnName	is-seed	Name of the column used to store the boolean of whether the current entry is a seed.
viaColumnName	via	Name of the column used to store the via information.
urlColumnName	url	Name of the column used to store the url.
requestColumnName	request	Name of the column used to store the request header.
separateHeaders	false	Separate the HTTP response headers from the content.
maximumContentSize	-1	Maximum size of the content string that will be saved. Anything larger will just not write to Cassandra. -1 indicates unlimited size.

Building

If you can't find a release that corresponds to your combination of Heritrix and Cassandra versions, then you can build your own version of heritrix-cassandra (granted that the APIs of each application haven't changed dramatically).

1. Obtain the heritrix-cassandra source from http://github.com/openplaces/heritrix-cassandra
2. Install Gradle (http://www.gradle.org/installation.html)
3. Edit build.gradle and change the properties "version", "heritrix_version", "cassandra_version" accordingly.
4. Run "gradle jar" in the command line, and your new jar should be in the build/libs folder.

Releases

Each release of heritrix-cassandra is compiled against different version combinations of Heritrix and Cassandra. The following table summarizes them.

heritrix-cassandra	Heritrix	Cassandra
0.8	3.1.0	0.7.6-2
0.7	3.0.1	0.6.5
0.5	3.0.0	0.6.1
0.4	3.0.0	0.6.1
0.3	3.0.0	0.6.0
0.2	3.0.0	0.6.1
0.1	3.0.0	0.6.0