Tech Blog

How should a "perfect" search project be run?

Gaston Gonzalez — Mon, 06 Feb 2012 16:50:12 +0000

Mark Owen, an ECM expert blogger from AIIM, adapted one of the discussion threads I was involved in on LinkedIn into a blog post. Check out the post on "How should a 'perfect' search project be run?"

CQ5 WebDAV Support for Windows 7 64-bit

Gaston Gonzalez — Fri, 30 Dec 2011 15:21:55 +0000

After a long break from working in the content management space, I returned to my CMS roots with a focus on CQ5. As a novice CQ5 developer, I've been chipping away at CQ5 recipes such as: As a developer, I would to like to access the CRX via WebDAV on my Windows 7 workstation. Simple question, right? Wrong. As it turns out Windows 7 64-bit does not support mapping a WebDAV resource easily. Sure, there were claims that applying KB907306 would do the trick. This didn't work. There were instructions on mucking with the registry. Really, this isn't the 90s. No thank you. Oh, wait...there are third-party freeware packages such as BitKinex. Again, no thank you. Lastly, there were some articles around changing the authentication scheme from Basic Authentication to Digest Authentication. Why can't I have native support!

Enough with the rant. I recently had a good experience building a command line WebDAV client under Linux (CentOS) called cadaver. As a command line guy, I already had Cygwin running under Windows 7. Sure enough, Cygwin supports cadaver under All > Web.

For those of you running Windows 7, need WebDAV support and don't mind using the command line, try cadaver out. Once installed, connecting to the CRX is pretty painless.

Launch Cygwin
Create a file called ~/.netrc and include the following lines. This will allow you to interact with the CRX without being promoted for a username and password.
```
machine localhost
login admin
password admin
```

Run cadaver.

$ cadaver http://localhost:4502/crx/repository/crx.default

You should now receive a shell to interact with the CRX. Most of the commands are similar to a command line FTP client (ls, cd, get, etc.). Simply type help for a list of available commands.

Apache Felix - Example 3 Continued: Testing Service Unregistration

Gaston Gonzalez — Wed, 07 Dec 2011 00:21:54 +0000

Apache Felix Tutorial Example 3 walks the user through an implementation of a simple dictionary service. At the end of the tutorial, it describes a use case in which the dictionary service is unregistered. Under this scenario, the code in the example should throw a null pointer exception.

I was curious how to force this use case and came up with the following additional steps to experiment with unregistering the service while the client was using it. We just need access to another shell so that we can have the client running in one shell, and stop the service in a second shell.

Begin, by downloading the Remote Shell bundle under the subprojects section of the download page.
Install and start the Remote Shell bundle. This will provide remote access to the Felix shell via Telnet.
```
start file:/path/to/download/org.apache.felix.shell.remote-1.1.2.jar
```
Open your preferred Telnet application, such as putty, and set the port to 6666 and the host to localhost.

In your original shell (not the remote) start the example 3 client.

g! lb | grep Client
START LEVEL 1
   ID|State      |Level|Name
   12|Resolved   |    1|Dictionary Client (1.0.0)
g! start 12
Enter a blank line to exit.
Enter a word:
testing
No match found!

Find the ID of the English dictionary service and stop it.

g! lb | grep English
 10|Resolved  |   1|English dictionary (1.0.0)
g! stop 10

Lastly, go back to the shell running the dictionary client and enter a new word. You should now receive a null pointer exception!

Enter a word:
testing2
org.osgi.framework.BundleException: Activator start error in bundle [12].
        at org.apache.felix.framework.Felix.activateBundle(Felix.java:2027)
        at org.apache.felix.framework.Felix.startBundle(Felix.java:1895)
        at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:944)
        at org.apache.felix.gogo.command.Basic.start(Basic.java:729)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.felix.gogo.runtime.Reflective.invoke(Reflective.java:137)
        at org.apache.felix.gogo.runtime.CommandProxy.execute(CommandProxy.java:82)
        at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:477)
        at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:403)
        at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:183)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:120)
        at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:89)
        at org.apache.felix.gogo.shell.Console.run(Console.java:62)
        at org.apache.felix.gogo.shell.Shell.console(Shell.java:203)
        at org.apache.felix.gogo.shell.Shell.gosh(Shell.java:128)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.felix.gogo.runtime.Reflective.invoke(Reflective.java:137)
        at org.apache.felix.gogo.runtime.CommandProxy.execute(CommandProxy.java:82)
        at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:477)
        at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:403)
        at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:183)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:120)
        at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:89)
        at org.apache.felix.gogo.shell.Activator.run(Activator.java:75)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
        at com.gastongonzalez.felix.tutorial.example3.Activator.start(Unknown Source)
        at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:641)
        at org.apache.felix.framework.Felix.activateBundle(Felix.java:1977)
        ... 32 more
java.lang.NullPointerException

Apache Felix - Bundle Installation and NoClassDefFoundError

Gaston Gonzalez — Thu, 01 Dec 2011 23:21:50 +0000

I am on day two of a long journey to master OSGi. As such, I have been working through the OSGi tutorials on the Apache Felix site. As I continue down this path, I thought I would document the issues that I encounter as a novice, hopefully, helping others at my same level.

This afternoon, I tried installing a new bundle (felix-tutorial-example5.jar) and received a java.lang.NoClassDefFoundError exception for the ServiceTracker class. As it turns out, I forgot to import the org.osgi.util.tracker package in my manifest. So next time you receive a NoClassDefFoundError exception when installing a bundle, check that you have all of your import packages defined.

The Solution:

Import-Package: org.osgi.framework, 
 org.osgi.util.tracker,
 com.gastongonzalez.felix.tutorial.example2.service

The Problem:

g! felix:start file:/c:/temp/felix-tutorial-example5.jar
org.osgi.framework.BundleException: Activator start error in bundle [28].
        at org.apache.felix.framework.Felix.activateBundle(Felix.java:2027)
        at org.apache.felix.framework.Felix.startBundle(Felix.java:1895)
        at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:944)
        at org.apache.felix.gogo.command.Basic.start(Basic.java:729)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.felix.gogo.runtime.Reflective.invoke(Reflective.java:137)
        at org.apache.felix.gogo.runtime.CommandProxy.execute(CommandProxy.java:82)
        at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:477)
        at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:403)
        at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:183)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:120)
        at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:89)
        at org.apache.felix.gogo.shell.Console.run(Console.java:62)
        at org.apache.felix.gogo.shell.Shell.console(Shell.java:203)
        at org.apache.felix.gogo.shell.Shell.gosh(Shell.java:128)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.felix.gogo.runtime.Reflective.invoke(Reflective.java:137)
        at org.apache.felix.gogo.runtime.CommandProxy.execute(CommandProxy.java:82)
        at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:477)
        at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:403)
        at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:183)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:120)
        at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:89)
        at org.apache.felix.gogo.shell.Activator.run(Activator.java:75)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: org/osgi/util/tracker/ServiceTracker
        at com.gastongonzalez.felix.tutorial.example5.Activator.start(Unknown Source)
        at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:641)
        at org.apache.felix.framework.Felix.activateBundle(Felix.java:1977)
        ... 32 more
Caused by: java.lang.ClassNotFoundException: org.osgi.util.tracker.ServiceTracker not found by[28]
        at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1460)
        at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringIm
pl.java:72)
        at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadCla
ss(BundleWiringImpl.java:1843)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 35 more
java.lang.NoClassDefFoundError: org/osgi/util/tracker/ServiceTracker

FAST ESP Error: Document summary too short, couldn't unpack

Gaston Gonzalez — Sat, 24 Sep 2011 14:50:05 +0000

The FAST ESP error, Document summary too short, couldn't unpack, occasionally occurs after performing an index profile update. In the past, my solution to this problem involved executing a manual cold update. While this works every time, it does require that you refeed all of your content. Definitely not the ideal solution when dealing with a production system.

I discovered a TechNet posting this morning that offers another solution that's not destructive. The following are the steps described in the post:

Stop the QR Server (nctrl stop qrserver).
Delete the %FASTSEARCH%\var\qrserver\webcluster\15100\cache_cs directory.
Start the QR Server (nctrl start qrserver).
Stop Search (nctrl stop search-1).
Delete the %FASTSEARCH%\var\searchctrl directory.
Start Search (nctrl start search-1)
Repeat the above steps on any systems in the cluster running a QR Server or Search component.

A big thanks to Rob Va for the solution!

FAST Search Engineer's Guide: An Alternate Approach to SBC Absolute Position Boosting

Gaston Gonzalez — Mon, 05 Sep 2011 23:36:35 +0000

Given the relatively closed nature of FAST ESP, there are a number of areas that are not well documented. This makes our jobs as search engineers difficult when we are required to solve a problem in one of these undocumented, or lightly documented areas.

In March 2011 I wrote a white paper, FAST Search Engineer's Guide: An Alternate Approach to SBC Absolute Position Boosting, that describes a method for applying SBC-style Top 10 or Absolute Position boosts without the use of SBC.