Maria del Carmen Barandela PazosCERNCHEP 2-7 Sep 2007 Victoria

LHCb Online Interface to the Conditions Database

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

OUTLINE

● Conditions , Conditions DB & LHCb Online

● LHCb Online Interface to the CONDB

○ System components

○ Data flow

● Summary

- 1-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

CONDITIONS

- 2-

● Non-event detector data that vary with time

TIME

DATA ITEM

VERSION

● Condition Object:

- Metadata

- Payload

• Data item identifier• Interval of Validity: [since, until]• Version information

• Actual data variables: temperatures, calibration parameters, etc.

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

CONDITIONS DBFOLDER SETS

FOLDERS

IOVs

OBJECT DATA

Hierarchical organization&

Versioning

Interval of Validity access&

Versioning

Data payload<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE DDDB SYSTEM "conddb:/DTD/structure.dtd"><DDDB><condition name=""><param name="" type=""> </param></condition></DDDB>

- 3-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

ONLINE CONDB

2

Expe

rimen

tal E

quip

men

t

PVSSPVSS

PVSSPVSS

Online

Offline

Online

Offline

- Subset of monitoring data from HW

- Online Usage

• Publisher: control system

• Consumer: trigger processes

LHCb pit CERN

- 4-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

INTERFACE TO CONDB

2

● Store data produced in the LHCb pit

● System components

- Communication layer

- PVSS panel

- PVSS control scrip

• SCADA(Supervisory Control and Data Acquisition)• Developed by ETM• Software package for control and visualization

- Conditions database server: COOL• API for reading and writing conditions data• Developed by LCG group at CERN• Management condition data in the LHC experiment

• DIM (Distributed Information Management ) system• Developed at CERN • Machine independent inter-process communications

- 5-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

PVSS PANEL

2

● Display existing nodes in the CONDB● Define conditions● LHCb framework component

● Select parameters &

update type

● Condition update type- Time

- Change value- Value + or – value or %

- Opt. Combination

● Server status & error msn● Visualization XML

- 6-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

PVSS CTRL SCRIPT

2

● Creates 1 thread per condition

● Gets the existing definitions stored as dpe.

● When is the right moment :

- Builds the XML string

● Independent from the panel - Gets automatically new condition definitions

-Sents the condition to the server

dpe

CTRL SCRIPT

XML XML XML

dpe dpe

- 7-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

CONDB SERVER

2

● Receives the conditions as DIM command

● Publishes the CONDB nodes as DIM service

● Generic implementation

COOL Different relational backends

SQLITE &

Oracle

- 8-

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

DATA FLOW

2- 9-

PVSS DNSDIM Name Server

CONDBSERVER

Online CONDDB

1. Get conditions info

3. Request conditions service

4. Service info

5. Condition Service info

6. Command: updated condition

7. Insert the updated condition

2. Register services

Maria del Carmen Barandela Pazos CHEP 2007, Victoria

SUMARY

2- 10-

● Simple and flexible way to define conditions

● System fully functional (still being tested by users)

● Generic implementation of the server

Questions