Troubleshooting javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure

Re-published from the Telia Tech Blog. The infamous Java exception javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure is hardly understandable to a mere mortal. What it wants to say is, most likely, something like this: Sorry, none of the cryptographic protocols/versions and cipher suites is accepted both by the JVM and the server. For instance the server

Kioo: How to Troubleshoot Template Processing

So you have created an Om/Reagent/React component using a Kioo template and the result is not as you expected, perhaps just an empty element? Let me share what I have discovered about troubleshooting this (though I am no expert). You will se how to invoke the underlying Clojure function component* manually, how to expand the

Installing & Troubleshooting Google Analytics 2013 (ga / analytics.js)

Setting up the new Google Universal Analytics (still in beta) is not completely obvious. You normally won’t be able to send events from localhost and it will claim that “Tracking Not Installed.” Here are some tips how to use Analytics from localhost and test it.

Note To Self: What to Do When a Vagrant Machine Stops Working (Destroy or Up Failing)

Sometimes “vagrant destroy” fails with an exception from the depths of the virtualbox Ruby gem or vagrant up freezes for a long time only to fail with SSH connection failure message. Here are some tips how to solve such problems. See also my Vagrant Notes.

Inspect Your Webapp in a Live Environment Interactively with GroovyConsole

Have you ever needed to check the state of your webapp’s objects/Session/.. to find out why the hell something doesn’t work or have you had to learn a weird 3rd party API that is only available on the server? Then you were doomed … until the publication of GroovyConsole. JeeUtils GroovyConsole provides a JSP page that

Troubleshooting logging configuration (Log4j, commons-logging)

Did it ever happen to you that your logging didn’t behave as expected? Here are some tips how to find out what’s going on. Commons-logging (since 1.1) Set the system property org.apache.commons.logging.diagnostics.dest to STDOUT (or STDERR or a file name); docs: -Dorg.apache.commons.logging.diagnostics.dest=STDOUT Extract of a sample output (no commons-logging.properties): Extract of a sample output (incorrect

Troubleshooting Class/Resource Loading on an Application Server

If you need to find out where is a certain class loaded from or where a class has loaded a resource (typically a configuration file) from, you can use the JSP below – just put it to your web app and point a browser to it. Note: The resource loading tracking assumes that the loading

DB2: Find out current locks, long transactions etc. [snapshot]

To find out current locks in a DB and other information about its current state, you need to take a “snapshot”: db2 “attach to user using ” db2 “get snapshot for applications on ”  > mydatabase_snapshot.txt Look into the resulting mydatabase_snapshot.txt for “Application ID holding”  (if there is a lock, this will read the ID