Database Server Concepts and Possibilities

1
Database Server Concepts and Possibilities

• Lee Lueking
• D0 Data Browser Workshop
• April 8, 2002

2
What Role Does The DB Server Play?

• The DB server represents the middle tier of a
  three tier architecture.
• Reference material available at
  http//d0db-dev.fnal.gov/db_server_gen

Client
Client
Client
CORBA
DB Server
SQLnet
Database
Oracle
3
What Are Pros and Cons of 3 Tier Architecture?

• Advantages
• Significantly reduces the required number of
  concurrent client licenses required (significant
  savings when using commercial db).
• Enables any internet connected node to run
  client processes.
• Insulates client from changes in DB schema, and
  visa versa.
• Enables client applications to be coded in any
  language.
• Much more scalable approach 1) Allows customized
  caching and other services to be built into
  middle tier, 2) Dbservers can be operated on
  cheap hardware.
• Disadvantages
• Complex environment
• Debugging at all tiers more complicated.
• Adds additional level of abstraction for
  developers and users.
• Reduces effectiveness of Oracle server caching
  and optimization

4
Where Do We Use DB Serves?

• SAM specific servers
• SAM user (serves SAM users)
• SAM prd (serves most SAM stations)
• SAM web (dedicated to web-based dataset editor)
• DLSAM (dedicated to online station)
• Central-Analysis (dedicated to CA station)
• D0 Farm (dedicated to D0 FNAL processing farm)
• Offline Trigger DB
• Offline Luminosity
• Generalized servers
• Offline Calibration (many)
• Offline Run Config

5
Using a DB Server With a Browser

• Can easily develop a DB browser for any CORBA
  enabled framework.
• Could create interface ROOT interface to allow
  creation of ROOT trees for analysis (similar to
  Andreis approach).
• The web-based SAM dataset editor uses a Java
  Servlet and Java Server Pages (JSP) to provide a
  performant tool for viewing (and modifying in the
  SAM case) database tables.
• Other tools could be used, like php.

6
The SAM Dataset Definition Editor

• Uses the Apache and Tomcat (specific
  implementation of JS and JSP)
• Dataset definition editor

7
Future DB Server Features

• The Second Generation general DB server is now
  in design.
• Has much better caching, monitoring, connection,
  and robustness features.
• Jim can discuss this