NoSQL
HBase has disappearing rows
I guess this may have a place if your application data is transient in nature and doesn’t need to be retained forever. We first take an existing table and for a given column family set its “time to live” to 30 seconds. According to the documentation, the cell will be removed after this time.... »
HBase JMX metrics
HBase exposes several metrics via JMX beans, some of which are similar to the Oracle performance counters recorded by AWR. Actually, they aren’t even *close* to what Oracle provides, but one can hope Below is a simple example of how these can be exposed: Download the jmx command line client jar from http://crawler.archive.org/cmdline-jmxclient/downloads.html Configure... »
Flashback ability with HBase
Oracle has a great feature called flashback query. This allows a user to (try to) query a row as it existed at some point in the past. It provides this functionality by trying to find the necessary UNDO to reconstruct the row as it existed at the time the user requested. If the necessary... »
Printing all property values in an HBase configuration
I’m sure there is an easier (perhaps built-in) way to do this, but for now, I wanted to document how you can print all properties for a given configuration that you load into a JVM. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19... »
Simple HBase stress tester
What is below is a simple class to read a random set of records from a table. This should be a good start if you are looking for a simple one class test case, that may also be useful for simple stress testing. As other example regarding HBase, it assumes you have configured your... »
Simple HBase class to load data
What is below is a simple java class to load the customers table we created in a previous post 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 import java.util.*; import org.apache.hadoop.hbase.client.*; import org.apache.hadoop.hbase.util.*; ... »
Bridging the gap…from SQL to No SQL
For any DBA’s that have had someone call them and ask “What do you know about NoSQL?”, this post is specifically intended. Before you have a conniption fit and began quoting Tom Kyte-ism’s (an exceptionally smart guy, if you do want to quote him ), realize that software is not a religion, and sometimes... »