We generate a daily health check report for each database that contains high level summaries of the previous days activities. One element of this report is a list of the top ten non idle wait events (disclaimer: I know that…
Author: Steve
Useful script to print session gv$sesstat changes over time
Oracle provides a plethora of tools for monitoring user activity, including tracing, monitoring wait events, as well as ASH. However, sometimes I want a quick (literally) overview of a session. To do this, I query the gv$sesstat view. However, the…
Constructing a thread when you don’t know the class ahead of time
While building a generic load testing toolkit, I found it useful to be able to use a standard invocation framework for running a thread class that contains the actual application code to be stress tested. However, I had some problems…
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…
Printing hadoop properties
The hadoop Configuration class implements the Iterable interface, so you can simply create a default configuration and list all properties, or pass a custom XML configuration file and print the properties from that. Below is a simple example. import java.util.*;…
ipcrm not removing SGA shared memory segment
Today, I had an issue I had seen before, but I can never remember how I fix it. As such, I wanted to document it here. Although rare, periodically an abnormally terminated instance will leave behind a shared memory segment.…
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…
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. import java.util.*; import org.apache.hadoop.hbase.*; import…
Loop through and print directory size
Set objShell = CreateObject(“WScript.Shell”) Set objFSO = CreateObject(“Scripting.FileSystemObject”) Set objFolder = objFSO.GetFolder(“C:\”) Set colSubfolders = objFolder.Subfolders For Each objSubfolder in colSubfolders on error resume next Wscript.Echo objSubfolder.Name, objSubfolder.Size Next
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…