How to select rows in cassandra for indexing in solr - solr

Question

I have rows in cassasndra, how would I go on about quering those rows in order to index them for example in solr. What query or what way should i use in order to query all those rows in cassandra once?

Answer 1

Please find below the example to integrate Cassandra and Solr:
CREATE TABLE tutor (
id int,
name text,
org text,
dep text,
sal text,
place text,
PRIMARY KEY ((org),name)
)
cqlsh:test> select * FROM tutor;
org | name | dep | id | place | sal
------+------+------+----+---------+------
org1 | abc | dep1 | 1 | sanjose | 4500
org1 | bbb | dep1 | 2 | sanjose | 5500
org2 | ccc | dep1 | 3 | sanjose | 5500
org2 | ddd | dep2 | 4 | sanjose | 5500
org2 | eee | dep3 | 5 | sanjose | 4500
org2 | fff | dep4 | 6 | sanjose | 7500
Requirements for SOLR and Cassandra integration:
SOLR version:
solr 4.9.0
Lib/Jar:
Cassandra :
cassandra-all-1.2.5.jar
libthrift-0.6.0.jar
cassandra-thrift-1.2.5.jar
Daata Import Handler:
solr-dataimporthandler-4.9.0.jar
solr-dataimporthandler-extras-4.9.0.jar
MySql:
mysql-connector-java-5.1.31-bin.jar
In Solor: Following files to be update:
• dataconfig.xml
• schema.xml
• solorconfig.xml
• dataconfig.xml
Here we have to update the JDBC connector for CASSANDRA.
< dataConfig>
< dataSource type="JdbcDataSource"
driver="org.apache.cassandra.cql.jdbc.CassandraDriver"
url="jdbc:cassandra://10.234.31.231:9160/test"
autoCommit="true"/>
< document name="content">
< entity name="test"
query="SELECT id,org,name,dep,place,sal from tutor" autoCommit="true">
< field column="id" name="id" />
< field column="org" name="org" />
< field column="name" name="name" />
< field column="dep" name="dep" />
< field column="place" name="place" />
< field column="sal" name="sal" />
< entity>
< document>
< dataConfig>
schema.xml
< field name="id" type="string" indexed="true" stored="true" required="true" />
< field name="org" type="string" indexed="true" stored="true" required="true" />
< field name="dep" type="string" indexed="true" stored="true" required="true" />
< field name="place" type="string" indexed="true" stored="true" required="true" />
< field name="sal" type="string" indexed="true" stored="true" required="true" />
Solorconfig.xml
< ! - - Add your library Path - →
< lib dir="/home/solr/lib" regex="solr-dataimporthandler-.*.jar" />
< lib dir="/home/solr/lib" regex="cassandra-jdbc-.*.jar" />
< lib dir="/home/solr/lib" regex="cassandra-all-.*.jar" />
< lib dir="/home/solr/lib" regex="cassandra-thrift-.*.jar" />
< lib dir="/home/solr/lib" regex="libthrift-.*.jar" />
. . . . . . . . . . .
. . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
< requestHandler name="/dataimport" class="org.apache.solr.handler.dataimport.DataImportHandler">
< lst name="defaults">
< str name="config">dataconfigCassandra.xml
< /lst>

Answer 2

Not sure how is your setup (which language you are using), but probably the best is to use a Cassandra client library and write an applications to query all the entries (rows) of your cassandra "column family" (tables) and then write the data you want to index from each row in Solr. Here you have a nice overview of several clients for cassandra: http://www.datastax.com/download/clientdrivers.
To perform the "read all entries" you can perform the following "native query":
select * from columnfamilyname;
This will depend very much on the client library you use... but I imagine most of the clients allow you to do such "native queries" (like the ones you perform in Cassandra cassandra-cli or cqlsh).
Be careful how big is your DB to perform this query... In that case if you if they are indexed/ordered (by key) you can perform a query such as: select * from columnfamily where indexkey > 101 limit 100 allow filtering.
After you create the "initial index" in Solr, most probably you should also use an update method that keeps solr index updated with new entries of the Cassandra DB.