Apache Accumulo RowHash Example
This example shows a simple map/reduce job that reads from an accumulo table and writes back into that table.
To run this example you will need some data in a table. The following will put a trivial amount of data into accumulo using the accumulo shell:
$ ./bin/accumulo shell -u username -p password Shell - Apache Accumulo Interactive Shell - version: 1.6.0 - instance name: instance - instance id: 00000000-0000-0000-0000-000000000000 - - type 'help' for a list of available commands - username@instance> createtable input username@instance> insert a-row cf cq value username@instance> insert b-row cf cq value username@instance> quit
The RowHash class will insert a hash for each row in the database if it contains a specified colum. Here's how you run the map/reduce job
$ bin/tool.sh lib/accumulo-examples-simple.jar org.apache.accumulo.examples.simple.mapreduce.RowHash -u user -p passwd -i instance -t input --column cf:cq
Now we can scan the table and see the hashes:
$ ./bin/accumulo shell -u username -p password Shell - Apache Accumulo Interactive Shell - version: 1.6.0 - instance name: instance - instance id: 00000000-0000-0000-0000-000000000000 - - type 'help' for a list of available commands - username@instance> scan -t input a-row cf:cq [] value a-row cf-HASHTYPE:cq-MD5BASE64 [] IGPBYI1uC6+AJJxC4r5YBA== b-row cf:cq [] value b-row cf-HASHTYPE:cq-MD5BASE64 [] IGPBYI1uC6+AJJxC4r5YBA== username@instance>
