# Presentation: 328295

## Data Management

**Data Management**

- D0 Monte Carlo needs
- The NIKHEF D0 farm
- The data we produce
- The SAM data base
- The network
- Conclusions

**Kors Bos, NIKHEF, Amsterdam**
**Fermilab, May 23 2001**

## D0 Monte Carlo needs

**D0 Trigger rate is 100 Hz, 10****7**** seconds/yr ******** 10****9**** events/yr**
**We want at least 10% of that be simulated ******** 10****8**** events/yr**
**To simulate 1 QCD event takes ~3 minutes (size ~2 Mbyte)**
- On a 800 MHz PIII
**So 1 cpu can produce ~10****5**** events/yr (~200 Gbyte)**
- Assuming a 60% overall efficiency
**So our 100 cpu farm can produce ~10****7**** events/yr (~20 Tbyte)**
- And this is only 10% of the goal we set ourselves
- Not counting Nijmegen D0 farm yet
**So we need at least an order of magnitude more**
- UTA (50), Lyon (200), Prague(10), BU(64),
- Nijmegen(50), Lancaster(200), Rio(25),

## Example: Min.bias

- Did a run with 1000 events on all cpu’s
- Took ~2 min./event
- So ~1.5 days for the whole run
- Ouput file size ~575 MByte
- We left those files on the nodes
- reason for enough local disk space !
- Intend to repeat that “sometimes”

## Output data

- -rw-r--r--   1 a03      computer               298 Nov  5 19:25 RunJob_farm_qcdJob308161443.params
- -rw-r--r--   1 a03      computer 1583995325 Nov  5 10:35 d0g_mcp03_pmc03.00.01_nikhef.d0farm_isajet_qcd-incl-PtGt2.0_mb-none_p1.1_308161443_2000
- -rw-r--r--   1 a03      computer                791 Nov  5 19:25 d0gstar_qcdJob308161443.params
- -rw-r--r--   1 a03      computer                809 Nov  5 19:25 d0sim_qcdJob308161443.params
- -rw-r--r--   1 a03      computer      47505408 Nov  3 16:15 gen_mcp03_pmc03.00.01_nikhef.d0farm_isajet_qcd-incl-PtGt2.0_mb-none_p1.1_308161443_2000
- -rw-r--r--   1 a03      computer              1003 Nov  5 19:25 import_d0g_qcdJob308161443.py
- -rw-r--r--   1 a03      computer                912 Nov  5 19:25 import_gen_qcdJob308161443.py
- -rw-r--r--   1 a03      computer              1054 Nov  5 19:26 import_sim_qcdJob308161443.py
- -rw-r--r--   1 a03      computer                752 Nov  5 19:25 isajet_qcdJob308161443.params
- -rw-r--r--   1 a03      computer                636 Nov  5 19:25 samglobal_qcdJob308161443.params
- -rw-r--r--   1 a03      computer    777098777 Nov  5 19:24 sim_mcp03_psim01.02.00_nikhef.d0farm_isajet_qcd-incl-PtGt2.0_mb-poisson-2.5_p1.1_308161443_2000
- -rw-r--r--   1 a03      computer              2132 Nov  5 19:26 summary.conf

## Output data translated

**0.047** Gbyte  gen_*
**1.5** Gbyte  d0g_*
**0.7** Gbyte sim_*
- import_gen_*.py
- import_d0g_*.py
- import_sim_*.py

- isajet_*.params
- RunJob_Farm_*.params
- d0gstar_*.params
- d0sim_*.params
- samglobal_*.params
- Summary.conf

**12** files for generator+d0gstar+psim
- But of course only 3 big ones
- Total ~2 Gbyte

- Per Day, on 100 cpu’s
- Total 200 Gbyte/day !

## Automation

- Mc_runjob (modified)
- Prepares MC jobs (gen+sim+reco+anal)
- (f.e.) 300 events per job/cpu
- Repeat (f.e.) 500 times
- Submits them into the batch (FBSNG)
- Ran on the nodes
- Moves the executable to the nodes + some files
- Copy to fileserver after completion
- A separate batch job onto the fileserver
- Data moves between nodes and server
- Submits them into SAM
- Sam does file transfers to Fermi and SARA
- Runs for a week ...

## fbs job:

- file server

- node

- SAM DB

- datastore

- fbs(rcp)
- fbs(sam)

- fbs(mcc)

- mcc request

- mcc input

- mcc output

- 1.2 TB

- 40 GB

- SARA

- control

- data

- metadata

- 1 mcc
- 2 rcp
- 3 sam

- 50 +

- datastore

- FNAL

## Network bandwidth

- NIKHEF SURFnet			1 Gbit
- SURFnet: Amsterdam  Chicago 	622 Mbit
- Esnet: Chicago  Fermilab		155 Mbit ATM
- But ftp gives us ~4 Mbit/sec
- bbftp gives us ~25 Mbit/sec
- bbftp processes in parallel ~45 Mbit/sec

- For 2002
-   NIKHEF SURFnet			2.5 Gbit
-   SURFnet: Amsterdam  Chicago	622 Mbit
-   SURFnet: Amsterdam  Chicago	2.5 Gbit optical
-   Chicago  Fermilab			? More than 155

## network capacity internally

## TA network capacity

- Geneva

- Abilene

- ESNET

- MREN

**NewYork**

**STAR-TAP**

**STAR**-**LIGHT**

- 622 Mb

- 2.5 Gb

## Network load last week

- Needed for 100  MC CPU’s: ~10 Mbit/s (200 GB/day)
- Available to Chicago: 622 Mbit/s
- Available to FNAL: 155 Mbit/s

- Needed next year (double cap.): ~25 Mbit/s
- Available to Chicago: 2.5 Gbit/s:  factor 100 more !!
- Available to FNAL: ??

## Conclusions

- Producing a lot of data is easy
- Storing a lot of data less easy, but still easy
- Moving a lot of data even less easy, but still easy

- So what is the problem?
- Managing a lot of data is difficult  metadata dbase
- The network around Fermilab/CERN  is getting tight
- Otherwise there is enough bandwidth !

- Conclusion:
- Do the easiest thing:
- Don’t store or move: recalculate !!