| Title: Apache Accumulo RowHash Example |
| Notice: Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you 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. |
| |
| 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: 1.5.0 |
| - 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: 1.5.0 |
| - 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> |
| |