# Presentation: 198580

## NOVAA  Networked  Object-Based  EnVironment  for  Analysis

- “Framework Components for Distributed Computing”
- Pavel Nevski, _Sasha Vanyashin_, Torre Wenaus
- US ATLAS Collaboration Meeting
- July 21-22, 1999

## Outline

- Goals
- Requirements
- Architecture
- Components
- Status
- Summary

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Motivations

- Unprecedented data volume and software complexity in new large HENP experiments (RHIC, LHC...)
- New approaches to analysis and data handling software
- Distributed computing environment (DCE) is vital and increasingly powerful
- Experience in developing DCE solutions for STAR
- Build on experience to develop DCE tools for use in similarly challenging environments
- BNL is planning to have a significant role in computing and physics analysis of LHC data

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Goals

- Develop software tools for
- coordination and control of widely distributed analysis development and physics analysis activity
- distributed management and analysis of very large datasets
- enhanced robustness, reusability and maintainability of analysis software
- For application in many global computing environments (ATLAS, STAR, ...)
- generic tools not tied to specific implementation choices
- select, templatable implementations provided such that NOVA components can be used in a baseline framework

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Requirements

- Support wide area data intensive analysis
- Define middleware services are required to permit analysis applications to effectively run over wide area networks
- Provide a rich set of features that applications can select and use to obtain the level of service they need to operate
- Define the features and the API's necessary to allow the application and middleware to communicate
- Integrate the middleware API's with the applications

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Design Approach

- Small, modular components; application-neutral interfaces
- Can be used as a coherent framework or in isolation to extend existing analysis systems
- Focused on support for C++ based analysis
- Used for all RHIC, LHC, other large experiments
- Emphasis on user participation in iterative development; real-world prototyping and testing (STAR, ATLAS)
- Extensive use of existing tools and technologies
- Must be readily available, true or de facto standards, well supported, widely used or showing good growth

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Component-based Architecture

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Tools and Technologies

- Third party tools and technologies used in NOVA:
- MySQL: relational database for catalogs, state information and simple objects: C-structs
- Apache: customizable (perl & PHP) web server for communication and monitoring
- XML: low-volume data exchange, software source distribution
- CORBA: low-volume interprocess data exchange
- ROOT: visualization and analysis tools

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Components

- NOVA components fall into four domains
- Regional Center
- Central management and execution of analysis
- Remote Client
- Mobile Analysis
- Middleware Components
- Data exchange and navigation tools
- Client/Server object request brokerage
- Data Management
- Data repository, catalogue, and interface
- Data model for simple objects (C-structs)

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Object Broker Use Cases

**Problem:**
- A user has a new idea that was not foreseen at the beginning. User modifies the structure of one object in his application. Application stores new objects in the database.
- Remote applications unaware of a new functionality may request objects in old format.
**Solution:**
- Application: provides metadata request (name, time, selectors...) and the application DataObject dictionary
- Database server: provides DataObject and the dictionary
- Object Request Broker module: converts DataObject according to the application dictionary
-                                *(Dynamic Brokerage)*

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Dynamic Object Broker

- NOVA Object Request Broker

- Regional Center Database Server

- Middleware Services

- Remote Application Client

- Object
- Request
- Broker

- Application
- DataObject

- Database
- DataObject

- Database
- Dictionary

- Application
- Dictionary

- Parameters Repository

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Dynamic Object Broker (2)

**Benefits:**
- Separation of database and analysis applications
- Robust interface (via built-in type checking)
- Dictionary built from C-header files or IDL-files
- Database access is independent of application code version: *user can read new dataObjects   with an old executable*

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Object Broker Use Cases (2)

**Problem:**
- Remote application (web browser) navigates current database hierarchy.
**Solution:**
- Object Request Broker at the Regional Center serves dynamic HTML DataObjects in format tailored according to application ID: Netscape or MS Internet Explorer
-  *(Static Brokerage) *

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Static Object Broker

- Remote Application Client

- NOVA Browser

- Regional Center Database Server

- Middleware Services

- Database
- API
- Module

- Application
- DataObject

- Database
- DataObject

- Database
- API Call

-   Application
- ID

- Parameters Repository

- Apache
- Web
- Server

- http://www.usatlas.bnl.gov/parameters

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Layered Interface

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Data Model

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL

## Summary

- What is NOVA?
- framework components for distributed computing
- What is NOVA status?
- several tools are tested in STAR,       others to be developed
- components prototyped for ATLAS:
- database storage of GEANT geometry/digitization  parameters        for simulation/reconstruction
- web-based database navigation

- US ATLAS Collaboration Meeting 7/21/99

- Sasha Vanyashin, BNL