What is below is taken from an actual analysis of heavy latching and invalid objects after a change was made. This was done in early 2011. For a long period of time, we have avoided making changes that would result…
Author: Steve
Apologies for site slowness
All, I am aware the site has been slow for the better part of a month. This morning, I finally took the time to look at the host on which my hosting partner (1and1.com) stores the site. User CPU utilization…
Does java reuse closed sockets when the host still has one open?
We were curious as to what the handoff is between an application that opens a network socket, and how the Linux OS handles it. Let’s assume we do what is below: import java.net.*; public class checkSocket { public static void…
Simulating shopper abandonment in JMeter
It is unrealistic to generate traffic to a website for load testing without taking into consideration the ongoing experience of the virtual shopper. For example, if pages took 30 seconds to load on a site, how likely would you be…
Crawling all SQL Server tables and columns for a specific value
We had a quick need to search all columns in every table during a data discovery exercise. This is by no means the most efficient, but it does work. It pulls 10,000 rows at a time from each table, and…
Akamai GTM
Akamai’s Global Traffic Manager, or GTM for short, is technology that allows a user to configure traffic to be sent to more than one data center, or at least more than one origin URL. For an Akamai primer, go here.…
net.ipv4.ip_no_pmtu_disc and don’t fragment
We received an email asking that we restart a given server as the ATG lock manager had a required lock and a scheduled job could not move forward. I don’t like to do that without some triage. We were stuck…
Querying hive from Excel
Install 32 bit driver from the following URL https://downloads.cloudera.com/connectors/hive-2.5.5.1006/Windows/ClouderaHiveODBC32.msi Start Excel and run the query wizard Create a new Data Source Enter the values shown below Enter the values shown below Click the Test button Select the stores table from…
Purging Akamai cache
To purge content from the cache on the Akamai edge servers, you can use the main LUNA control center, which will push the request out to the edge servers affected. As such, keep in mind the cache is not immediately…
Where is a given thread connecting?
We start by getting the PID of our running JVM… -bash-4.1$ jps 29527 Main 3560 Jps …then we print each lightweight process (threads in our JVM) in which we are interested. In our case, these are threads with zafu in…