1. Online – Data Storage and Processing
Status
Storage requirements:
Data Volume / Rate
Detector data
C&M data
Different data taking modes
Run Plan?
Simulated data
Processing requirements:
Simulation/Digitisation
Online monitoring
Reconstruction
Next Steps
Malcolm Ellis - DAQ Meeting - 26th September 2006

2. Malcolm Ellis - DAQ Meeting - 26th September 2006
Status
I had meant to have made some progress towards understanding the requirements of the online system by this meeting.
This has not happened.
So the following slides amount to a “to do” list (amongst pleas for help)...
Malcolm Ellis - DAQ Meeting - 26th September 2006

3. Malcolm Ellis - DAQ Meeting - 26th September 2006
Storage Requirements
Last year we came up with a very rough estimate for the data storage requirements for MICE (Stages I – VI).
We now need to refine this to make it a more accurate estimate and understand how much is required as a function of stage/phase.
In order to do this we need to know:
For each detector, what are the potential data taking modes (e.g. SciFi tracker – discriminators only, zero suppressed with ADCs and TDCs, all channels’ ADCs and TDCs, etc...) and the event sizes associated with each.
For the detectors, what different types of data will be taken (calibration, physics, cosmics, source, etc) and what data taking modes are likely for each.
For the controls and monitoring, what is the approximate size of the data and what are the plausible ranges.
For the run plan, for each stage of MICE how many events are we likely to need of physics and calibration data.
Malcolm Ellis - DAQ Meeting - 26th September 2006

4. Malcolm Ellis - DAQ Meeting - 26th September 2006
Detector Data
Detector data size is determined by choice of FEE (and firmware).
For each detector we need to identify the potential read out schemes, the event size for each and the most likely use of each.
SciFi – AFEIIT
Firmware under development. Old extrapolation based on AFEII prototype readout scheme, unlikely to be in the same format for real MICE data taking.
I will work with Terry Hart to get an estimate of the different modes that will be available and the data size for each.
TOF/CKOV/EMCAL
FEE choices still to be made in many cases
Some decisions (e.g. use of flash ADC) can have a significant effect on the data size!
I will work with Jean-Sebastien in the first instance, but it would be nice to have an “official” PID contact person...
Malcolm Ellis - DAQ Meeting - 26th September 2006

5. Malcolm Ellis - DAQ Meeting - 26th September 2006
C&M Data
Depends on decisions yet to be taken (archiving of data, transformation into a DB, partial storage in the detector data stream, etc...)
Once we have a reasonable idea of the number of process variables that we will be archiving, it should be possible to make an estimate of the output data size – perhaps an extrapolation from D0, DIAMOND, etc could be useful as a first guess?
Who should I contact for help with this?
Peter and Fritz can presumably help with the extrapolations, but do we have an idea of what MICE will be monitoring?
Malcolm Ellis - DAQ Meeting - 26th September 2006

6. Calibration and Alignment Scheme
Once we know how much data the experiment will generate under a given configuration (i.e. physics running, calibration, cosmics) from the detectors and C&M we can then need an estimate of the run plan in order to calculate the total data size for each stage/phase of MICE.
I will ask Yagmur for help with this.
Possibly the run plan will be discussed at CM16 and we may come away with a better idea of what to expect.
Malcolm Ellis - DAQ Meeting - 26th September 2006

7. Malcolm Ellis - DAQ Meeting - 26th September 2006
Simulated Data
In addition to the data taken by the detectors, we will need a substantial amount of simulated data.
The exact amount will require discussion with the Analysis group, but we have tended to assume that the order will be the same as for the number of real data physics events.
Once the preparations for the “Data Challenge” are complete (hopefully CM16) we will have a good idea of how much space is required for an average event (Simulated and Digitised) as well as how much CPU is required.
In particular, the simulation of RF background is many orders of magnitude more CPU intensive than the simulation of a muon passing through the complete stage VI, however takes up a much smaller amount of space in the output file.
Malcolm Ellis - DAQ Meeting - 26th September 2006

8. Processing Requirements
With the Data Challenge we will have a first reasonable estimate of the amount of CPU required to reconstruct simulated data.
We will also have reconstructed the KEK tracker data, and with these two pieces of information should be able to make a reasonable extrapolation to the MICE Stage VI case.
Already made a rough estimate of the order of 6-12 CPUs required for quasi real time processing.
Hopefully will just be fine tuning this number.
Once we start using the GRID for simulation tasks we can also start investigating the potential for fast turnaround on the GRID if computing resources vastly in excess of this will be required.
Malcolm Ellis - DAQ Meeting - 26th September 2006

9. Malcolm Ellis - DAQ Meeting - 26th September 2006
Online Monitoring
It has been assumed that we will require online event reconstruction at some level (for example, to allow beam line tuning by doing fast determination of the Twiss parameters).
The same system will also be able to provide low and high level reconstructed parameters for online monitoring.
I feel this is a lower priority than the storage requirements, but once we have a feel for the data rate and CPU requirements we will start to investigate what reconstructed parameters will be useful to monitor during data taking.
Malcolm Ellis - DAQ Meeting - 26th September 2006

10. Malcolm Ellis - DAQ Meeting - 26th September 2006
Next Steps
Actually do some of this work!
Will hopefully take advantage of the influx of mice to RAL in a few weeks time to get some first estimates of the numbers we need at CM16.
Once we have a first version of all of the required information, Paul and I will revisit the complete calculation of the data storage and online processing requirements.
Malcolm Ellis - DAQ Meeting - 26th September 2006