Very elegant example at http://blog.derekfarren.com/2015/02/how-to-implement-large-scale-market.html. What is below is just a complete script with what the link above provides, along with example of our output. Our file was formatted slightly differently, so we had to change the split command. We…
Author: Steve
React JS example with web service call
This is a simple example of using React JS to call a web service (simple web page in our example). Of course, a true web service would normally be the source of the data, this is just a simple example…
Oracle global temporary table and connection pool
Our question was what happens to the rows in a global temporary table when populated from a session obtained from a connection pool. Are they still there for the next application user to borrow the same session from the pool?…
Testing the overhead of creating connections vs using a pool in Weblogic
We had a need to understand the overhead of creating connections versus using a pool. Connection pooling is most beneficial when using very short lived database sessions. If the associated database request takes longer than a few seconds, we needed…
Getting memory by thread
This is not perfect, as the heap is shared. However, the documentation indicates that a ThreadMXBean can calculate how much is in use by each. The idea behind this would be to either instrument your code, or use byte code…
Impact of socket.SO_REUSEADDR
This is often used to get around an “address already in use” error. If you know the previous server program has been shutdown, you can set this socket option prior to the initial server bind, and then restart your program.…
Setting java command line flags when value is default
Just a snippet of how I proved we were setting values to the default. While this has no negative impact, it does result in needless conversations like… “Why did we set that?” “It’s the default, don’t worry about it.” “Really?…
Pentaho row level security example
Using the Metadata Editor, it should be placed at the Business Model layer, above any business tables. Click the data constraints section (or add that section with the olive green plus button in the screenshot below, if necessary), select the…
TCP zero window flow
When troubleshooting this condition, it is imperative that you obtain a thread dump on the client. There is a reason it cannot consume the data being sent to it from the server, so you need to understand why it is…
Can two switches talk to each other?
Yes, and you don’t even need a crossover cable for the connection on newer switches. One important proviso is that this can be only on the default VLAN. If you use a different VLAN, the mode must be trunk rather…