LhcbApplicationsWorkflows < LHCb

LHCb Web>LHCbComputing>LhcbApplicationsWorkflows (2016-08-16, FedericoStagni) (raw view)

---+ LHCb Applications and Workflows

This twiki provides information about the LHCb application stack, LHCb applications and workflows used on the grid

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---++ LHCb application stack

The LHCb software stack can be divided into three layers (see Fig 1), these are

   * *LHCb applications* (see below) such as simulation, reconstruction, etc
   * The *LCG Applications Area software*, these are middleware packages for different kinds of purposes, developed within HEP (such as the ROOT and GAUDI frameworks, GEANT4 detector simulation,  COOL Conditions Database access, CORAL relational database abstaction, etc.), Grid middleware clients (LFC, FTS, WMS, ...) and packages developed outside HEP (e.g. Boost, GSL, gcc, ...). 
   * The *Operating System*, at the moment these are Scientific Linux versions and Mac OSX

<figure>
 <img src="%PUBURLPATH%/%WEB%/%TOPIC%/softwarestack.png" alt="softwarestack.png" height="200" />
<figcaption>Figure 1: LHCb Software Stack<figcaption>
</figure>

The whole stack is made available on different combinations of Operating System, architecture, compiler and optimizations. These are denoted by a "platform string" such as "slc6-gcc47-x86_64-opt". 


---++ LHCb applications

LHCb applications are separate projects denoted to a specific task in the different possible workflows of LHCb data processing, these are 

| *Name* | *Purpose* | *Description* |
| GAUSS | Simulation | event generation and simulation of the detector response via GEANT4 |
| BOOLE | Digitization | simulation of the detector electronics |
| MOORE | Trigger | trigger software and generation of RAW events |
| BRUNEL | Reconstruction | reconstruction of RAW events into physics objects |
| DAVINCI | Analysis | analysis software used by physicists and also for stripping |
| NOETHER | ? | ? |

in addition there are underlying projects supporting these applications developed also within LHCb, these are 

| *Name* | *Purpose* | *Description* |
| LHCBDIRAC | Grid Interaction | used for all data processing and data management operations on the grid |
| GANGA | Analysis submission | used by physicists to submit their jobs to computing facilities |
| LHCB | Common software | contains the event model description and common algorithms |
| LHCBGRID | grid middleware | contains CMT interfaces to grid middleware clients (can overwrite LCGCMT) |
| LCGCMT | LCG/AA software | contains CMT interfaces to the LCG Applications Area software stack (maintained by CERN PH/SFT) |

---+++ Runtime environment 

A runtime environment for any of the above LHCb projects can be generated (after a LHCb group login) with *lb-run <PROJECT>*

This is the simplest way to generate a runtime environment and will provide you the latest available version. lb-run has many more options, you may consult "lb-run --help" for more details. 


---++ LHCb grid workflows

This section contains descriptions of the LHCb workflows used for data processing on the distributed computing facilities. 

---+++ Stripping

Stripping will use the reconstructed physics objects as input (file type FULL.DST) and select the events contained within into different physics streams (e.g. DIMUON, BHADRON, etc). The individual output files are merged in a second step into larger files of the same stream if either all events of a given run have been processed of the output of the individual files supersedes N GB of output (usually N=5). 

-- Main.StefanRoiser - 18 Feb 2014

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
png	softwarestack.png	r1	manage	80.6 K	2014-02-18 - 14:58	StefanRoiser	LHCb Software Stack

Topic revision: r2 - 2016-08-16 - FedericoStagni

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