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November 23, 2024

Tag: Accumulo

June 23, 2015

Accumulo and Hbase – Differences in its API, classes

by viggy — Categories: tech — Tags: , , , , , , , , , — Leave a comment

As part of my GSoC project, I am working on adding support of HBase in GeoWave. Currently Accumulo is already well supported. Hence one of my main task is to understand the existing tests and examples and add support for the same for a HBase store.
One of the main challenge I am facing is there is no easily available mapping of Accumulo Classes to HBase classes. So in this blog, I will try to do the same.

Basic Entity Classes
Accumulo HBase Remarks
Key KeyValue HBase doesnt have separate entity for Key and Value. It stores everything as byte[].
Value KeyValue
Mutation RowMutations Accumulo exposes put/putDelete method whereas HBase has Put and Delete classes to Put in and Delete a single row respectively.
Scanner/Writer Classes
Accumulo HBase Remarks
Scanner/ScannerBase Scan Accumulo has a structured class heirarchy for scanning where in HBase I have only used Scan as of now.

TODO: To add about establishing connection, authentication, Write to store, Iterators/Coprocessors

April 8, 2015

Setting up Geowave and integrating it with GeoServer for the development environment

by viggy — Categories: FSMK, project, Uncategorized — Tags: , , , , , , , — Leave a comment

Geowave is a library used to store, index and analyze geospatial data on top of Accumulo which is a free software implementation of Google’s Big Table. Accumulo in turn makes use of Zookeeper to handle distributed synchronization and uses Hadoop FileSystem for distributed and scalable storage of the data. Geowave decomposes multi-dimensional data to single dimensional data using a transformation called as Space Filling Curves. GeoServer is a java based server which provides a platform to view and edit geospatial data. Hence at an abstract level, we can summarize that the data which is transformed by goewave and stored(ingested) in Accumulo can be extracted and viewed from geoserver.
Following article will explain how we can setup the system to have Geowave and Geoserver working with Accumulo for a development environment.

Part 1: (more…)