This is a list of Frequently Asked Questions about the Longwell Project.
Feel free to add your own questions here, we'll answer them here for others's benefit.
Longwell's initialization script says "./longwell: line 104: mvn: command not found". What's wrong?
Longwell depends on Apache Maven and the Longwell initialization script assumes that Maven's main script mvn is located in your path. Make sure you follow the Maven installation instructions at the bottom of the page.
Longwell's initializaton script says "Error: JAVA_HOME is not defined correctly. We cannot execute java". What should I do?
Longwell needs to know where the Java Virtual Machine is located on your system. To understand if you have one installed you can type java -version from your shell, terminall or DOS prompt. If none is found, you need to download one and install it.
After you have it installed, you have to set the JAVA_HOME environment parameter to point to the location of where you installed the Java Virtual Machine.
On Windows, follow these instructions.
On UNIX, add something like export JAVA_HOME=/path/to/java to your ~/.profile or ~/.bashrd.
Longwell's log say "[ERROR] BUILD ERROR ... Cannot find parent: ...". What can I do?
When you run Longwell the first time and if you have never ran Maven before, Maven will attempt to download all the libraries that it needs and sometimes this results in errors. Our suggestion is to run longwell again until all the dependencies have been downloaded and this error won't appear again.
We don't know why but Maven's repository seems to have frequent failures, probably due to high load as it happens more regularely during business hours, but unfortunately it is not something that we can fix on our end.
Longwell's log says "[ERROR] VM #addNarrowingButton: ...". Should I worry?
This is due to a benign bug in code longwell stands on. Our tracker issue for this problem is here.
When I start Longwell it appears to get stuck and nothing happens?
The first time you start Longwell it creates an RDF data store and then populate it; this can take a while. During that period it will appear to have stalled.
Why is my RDF data not getting updated?
When Longwell is started without arguments, it reads the default repository. When you load data using ./longwell -r /path/to/data it is aggregated with that default repository rather than updated. If you wish to update your RDF data, you must load it into a new repository using the -d switch: ./longwell -r /path/to/data -d /tmp/blah1.
Longwell's log has a Java stacktrace in it. Should I worry?
Yes, it shouldn't do that. You can report those via our issue tracker.
How do I build a WAR to deploy on servlet container like Tomcat?
Type mvn war:war at the command line. Maven will build the war package for you and place it in the ./target directory.
After you have the war installed and expanded, you might want to modify the /WEB-INF/longwell.properties file to match your system settings.
How do I upgrade from older semantic banks?
If you're using an older version of Semantic Bank (anything prior to the switch to Longwell configurations), you'll want to consider upgrading.
If you do want to upgrade, you need to use our upgrading tool. Read the README.txt there for instructions and possible caveats to the upgrade process.
Why the name Longwell?
Longwell Green is the name of a neightborhood in Bristol, UK. The name was choosen by Longwell's original author Mark Butler (who lives in Bristol, UK) by looking searching on Google for "haystack bristol" (Longwell was supposed to be a prototype to show how to do a server-side version of Haystack).
What is the Longwell logo? and how was it made?
The longwell logo is a rendering of a real diamond cut done with the amazing Blender free software modeler and using its toon-shading capabilities. You'll find the source file of the blender scene here.
Is it possible to define Fresnel lenses only for the selection of RDF properties without affecting the default Longwell rendering style?
No, the two subsystems that present the different views are quite separated right now.
How do I make Longwell show maps?
TODO
I'd like to host my own Longwell service on my commercially-hosted server: what capabilities does my ISP have to provide, and what do i need to do?
Longwell is a Java Servlet, so your ISP needs to provide you the ability to run servlets (any J2EE container will do, say Tomcat, JBoss or Geronimo). That's it really, there is no other dependency. After that, type "mvn war:war" to generate a "war" package that you can deploy in your J2EE container (talk to your ISP on how to do this).
Can i use Longwell to browse RDF or OWL data from a URI (not on my local disk)?
No, not at the moment.
Can I change the order used to display facet values (e.g. an alphabetical sort option)?
No, not at the moment.
My question isn't answered here, what should I do?
You can either write your additional questions here directly above this question (a notification will be sent to the developers) or you can post them on our general mailing list (note: it will require you to subscribe).
How does is scale? What about performance?
How many records, facets, and values can you use - some thousands? 100.000? millions? Does SMILE scale with larger sets of data (gigabytes even without the XML/RDF markup) like WorldCat, arXiv etc.? -- Jakob 07:44, 16 November 2006 (EST)
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