HBase Write Path by Jimmy Xiang.
From the post:
Apache HBase is the Hadoop database, and is based on the Hadoop Distributed File System (HDFS). HBase makes it possible to randomly access and update data stored in HDFS, but files in HDFS can only be appended to and are immutable after they are created. So you may ask, how does HBase provide low-latency reads and writes? In this blog post, we explain this by describing the write path of HBase — how data is updated in HBase.
The write path is how an HBase completes put or delete operations. This path begins at a client, moves to a region server, and ends when data eventually is written to an HBase data file called an HFile. Included in the design of the write path are features that HBase uses to prevent data loss in the event of a region server failure. Therefore understanding the write path can provide insight into HBase’s native data loss prevention mechanism.
Whether you intend to use Hadoop for topic map processing or not, this will be a good introduction to updating data in HBase. Not all applications using Hadoop are topic maps so this may serve you in other contexts as well.