Data Quality Monitoring Data Quality Monitoring of the CMS Tracker of the CMS Tracker
Laura BorrelloScuola Normale Superiore and INFN Pisa, Italy
on behalf of the CMS Tracker collaboration
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
OutlineOutline
• DQM architecture in CMS• Tracker DQM• Graphical User Interface
• CMS GUI• Tracker GUI
• Historic DQM: long term monitoring• Data Certification• Summary
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
IntroductionIntroductionThe Data Quality Monitoring (DQM) is an important tool to ensure high quality data taking throughout the lifetime of the experiment.It is partitioned in:• Online
– Evaluate data integrity and sub-system operation• Check any problem and take a prompt action to solve it
• Offline– Identify problems in calibration constants and reconstruction– Check the quality of each run
• Data Certification– Define good runs for physics analysis
The DQM system in CMS is - implemented using the CMS software framework (C++ code) and ROOT - centralized across sub-detectors, DAQ, trigger
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
DQM overviewDQM overview
DQM Online- Real time - Fraction of data (10-15 Hz)- Full granularity
DQM Express Stream- Within 1-2 h- Fraction of data- Full granularity
DQM Prompt Reco- Within 48 h- Full statistics - Reduced granularity- Best alignment andcalibration constants
DATA
Online DQM
On-line Off-line
Express Stream
Prompt reconstruction
Off-line Condition DB
Alignment andcalibration constant
Visualisation
Data Certification
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
The CMS DQM workflowThe CMS DQM workflow
The DQM application of all CMS sub-systems based on same workflow
DQM Producer– books/fills histograms
DQM Consumer– Accesses histograms from source and performs further analysis, including quality tests– Write DQM output ROOT file (accessible with GUI and stored on disk)
GUI– Visualisation of the informationCMS GUI: common toolTracker GUI: optimised for Tracker
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Quality TestQuality Test
Tool developed to produce automatic qualification of histograms– Comparison with reference histograms using statistical tests to detect
unexpected behavior– Application of cuts to spot outliers
• Different type of results:
OK Warning Error
• Quality tests configured through XML files
• Histogram qualification by attaching a label
with the result of the test
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
The CMS Tracker consists of: 15148 micro-strip detector modules ~10 million channels 1440 pixel detector modules ~67 million channels
The CMS TrackerThe CMS Tracker
Tracker DQM requirements- Check single moduleoperation- Check global performance (track reconstruction)
High granularity results in a large number of histograms produced: ~300k- Need of specific tool to identify and debug problems- Common tools for Pixel and Strip
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Tracker DQMTracker DQMTracker DQM Producers book and fill histograms with information from different levels of reconstruction
– Raw data: readout and unpacking errors– Local reconstruction: Digi, Cluster, on/off track Clusters– Global reconstruction: Track parameters (, , pT, … )– Alignment: Residuals of hits
The Tracker DQM Consumer use information from single module to - Create summary histograms
- Perform Quality Test- Produce global DQM flags
Histograms are arranged in tree like folder structure (mirroring the geometrical layout)• Full Detector
– layers/disks....• Detector modules
Any problem identified from summary information can be investigated at module level
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Graphical User Interface (GUI)Graphical User Interface (GUI)
CMS GUI– Widely used to visualize DQM histograms for both Online and Offline – Very robust Capable of handing all histograms in ~100 ms– Used also for file archival
Tracker Expert GUI– Developed for Tracker experts and shifters– Used only during data taking (Online)
The Graphical User Interfaces used in DQM are web based- Easily accessible from everywhere no software installation is needed- Asynchronous Javascript and XML (Ajax) is used More responsive asynchronous communication minimizes dead time in browser Native “desktop-like” look and feel
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
CMS GUI: Summary PageCMS GUI: Summary Page
PIXEL STRIP TRACKING
•Report from each sub-system•2D map with Quality Test results•Quality Alarm:
95-100%, 85-95%, < 85%elements in a subsystem
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
CMS GUI: Sub-detector Layout CMS GUI: Sub-detector Layout Layouts for sub-detector shifters/experts
Histogram failed in Qtest with red border and comment
Short description and Link to Documentation Page
Histogram Image Size
Flexible options
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Tracker Expert GUITracker Expert GUITracker Expert GUI
- Attached to the DQM client and can interact with it
Complementary to the CMS GUI - allows for efficient debugging: easy switch between global overview plots and detailed histogram
Spot a problem on overview plots Navigate through detector Plot single module distributions on demand using easy click buttons
Main feature is one page overview in form of– TrackerMap (synoptic view of the full detector)– Summary histograms (monitor one variable for all modules simultaneously)
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Tracker Expert GUITracker Expert GUI
STRIP
PIXEL
Button to interact with client
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Tracker Map: StripTracker Map: Strip
Different Views:Geometric and Read-out
Zoom to a layer
Mouse hover enables detailed description
Synoptic view of the Strip detectorTrackerMap interactive SVG (Scalable Vector Graphic) format
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Historic DQMHistoric DQM• Extract summary information from DQM root files & store them in
the offline DB
• Extract quantities from DB to create trends
• Visualization of trends: automatically available in a web page
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Historic DQM: few examplesHistoric DQM: few examples
STRIPMPV of StoN for
On-Track clusters vs Run number
PEAK
DECO
PIXELMean raw charge
in Barrel vs Run number
New calib constant
Strip sub-detectors
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Data Certification in CMSData Certification in CMS• Manual data certification
– based on DQM shifters evaluation of results from Online and Offline DQM
• Automated data certification • Done in DQM application (Online and Offline) and based on DQM, power
supply and DAQ information• Apply defined cuts to some histograms• An algorithm is combining results to define an overall flag (good or bad) for
each subsystem (STRIP and PIXEL)
• Results of this process are stored in DQM root files and accessible through the DQM GUI
Final review of flags done by sub-system experts (Sign-off)
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Data Certification: TrackerData Certification: Tracker
Run Registry:Database to store informationand manage the creation of certification resultsDBS:Dataset Bookkeeping System
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Certification: StripCertification: StripCombine the module and layer level results per sub-systemModule level certification
- FED errors
- #Digis
- #Clusters
Layer level certification
- S/N of each layer
(per sub-system
TIB/TOB/TID/TEC)
Global performance
Performance in terms of sub-detector
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Certification: PixelCertification: PixelCheck the fraction of all Barrel or Endcap modules which pass certain cuts based
on:
- Any FED errors
- #Digis - Digi charge (raw charge in ADC) - Cluster size, #Clusters, cluster charge (OnTrack and OffTrack) - Mean and RMS for X and Y residuals - RecHit errors in X and Y
All information is then combined to define the final flag (good/bad)
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Certification: TrackingCertification: TrackingTracking certification based onTrack Rate, # of Reconstructed Hits per track, Chi2 per degrees of freedom
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
PerformancePerformance• DQM tool extensively used during cosmic data taking in CMS
• DQM system was stressed and tested deeply
• It operated stably even for runs lasted more than 17-18 h on line, and always stable in the offline processing
• About 480M events processed and used to– monitor performance– data certification
Resources usage– Online, with full granularity, together with the reconstruction ~2GB of RAM– Offline, with a reduced granularity in order to share resources with the other
processes, ~0.5 GB of RAM
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
SummarySummary
Tracker DQM successfully working in common CMS framework Sub-system specific tool: Tracker Expert GUI available to improve
identification and debugging of problems
Proved functionality and reliability in cosmic data taking: both in online and offline processing
DQM is ready for proton-proton collision
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Back-up slideBack-up slide
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
• Asynchronous communication minimizes dead time in browser • Only modified parts of browser updated
Ajax modelAjax model
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Traditional Web ModelTraditional Web Model
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Tracker Expert GUITracker Expert GUI
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Strip Expert GUI: Alarm ViewStrip Expert GUI: Alarm View
Layer Selection Get AlarmTree
Follow Alarm structure to find Faulty Modules and plot histograms
Qtest Result
7 October 2009 – ICATTP09
L. Borrello – The Data Quality Monitoring of the CMS Tracker
Strip Expert GUI: Module ViewStrip Expert GUI: Module View
Layer Selection
List of Modules
Get Module list
Select One or Multiple histograms
Draw Selected Histograms