Sunday, October 26, 2008

WebDAV with Apache2 and Windows

In case you haven't looked in a while, WebDAV modules are included with Apache 2 and 2.2. See for example for an installation overview.

This will work great for Mac clients (from "Finder" hit apple-k to connect as a remote web folder) with HTTPD basic authentication, but they will fail for Windows XP clients (either mapping as a drive or adding network location). The reason, it turns out, is that Windows is actually working correctly: it won't do Basic Auth over an insecure connection.

To solve this, use SSL. There's an overview of the problem and variuos solutions at See for example for some Apache + SSL instructions.

One Final Trick: Windows clients seem to have a problem with the trailing "/", so in your Apache httpd.conf file, use something like

<location /dav>

and not

<location /dav/>

for your WebDAV folder name.

Wednesday, October 08, 2008

Abstract: Services and Components for the QuakeSim Project

[Posting is part of our lab seminar series.]

We discuss two recent enhancements to the QuakeSim grid infrastructure. First, we describe our work to integrate QuakeSim Web services with large scale Globus deployments such as the US TeraGrid and Open Science Grid. Our implementation is based on the Condor BirdBath client libraries and provides a simplified and stateless API for accessing Globus resources. In addition to QuakeSim, we are developing a variation of this service to support the University of Minnesota’s VLAB project. We discuss integration of this service with TeraGrid information services for system load and queue wait time prediction, as well as security issues and prospects for deployment on NASA resources.

Our second focus is on work performed with the Scripps Orbit and Permanent Array Center’s archival data services for permanently deployed California GPS stations. We have developed a daily historical analysis Web service of the GPS data using RDAHMM. This service has been combined with an interactive Web interface that allows the user to view historical state changes in the GPS network. This archival data is available on a fourteen day delay, so we conclude with a discussion of the prospects for a nearer real-time network event detection system.