Visit of SLAC Folks to Caltech, August 20 2002

Participants were Julian Bunn, Tony Johnson, Joseph Perl, Edwin Soedarmadji, Conrad Steenberg, Max Turri, Mark Donszelmann, and Rick Wilkinson.

These notes authored by Conrad.


Julian gave a summary of the Caltech activities, focussing on data storage and analysis (as opposed to production) using a combination of two RDBMs (SQL server and Oracle) and web services. Slides.

Conrad gave a summary of the architecture of the Clarens web services layer, and a demo of remote analysis using Root as a Clarens client. (

Tony gave an overview of work being done on distributed analysis using JAS (

JAS was installed on some of the laptop machines handy at the meeting, and a set of JetMET data (or metadata at least) stored on a Caltech machine (Baldrick) was browsed on the spot using directions from Tony.

The concrete outcome/action items are as follows:

  1. An instance of distributed JAS should be installed at Caltech, and Edwin and Julian should look into using JAS, and specifically the SQL database connectivity support to complement their RDBMS data analysis efforts. [Tony, Julian or Edwin could probably give more details...]
  2. An instance of the Clarens server should be installed at SLAC (Max is the contact for this, Conrad to assist where needed). Tony and Max should look into where Clarens might be useful for fetching small bits of data that doesn't need the high throughput and low latency required for distributed JAS operation. Max will look into interfacing Clarens to SRB ( and/or the associated metadata catalog (MCAT) using the Python layer that SRB/MCAT provides.

Reservations were expressed as to reported setup difficulties with SRB/MCAT.

(It should be pointed out that a release of MCAT (and SRB?) running on top of PostgreSQL may be available soon according to Reagan Moore of SDSC)

Tony will look into putting Clarens client functionality into JAS, with the main hurdle to overcome being the security implementation that needs to be done on the JAS side.