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ENS Performance Meter (EPM) Tool

In order to provide users with a mean to assess current level of performance, the ENS Performance Meter (EPM) tool is made available.

It can be downloaded from the following link: https://www.onda-dias.eu/cms/dias-ens-tools/

The following parameters have been defined to characterise ENS performances:

  • Data browsing performance value (sec): time needed for the execution of a “ls” command.
    • To be evaluated outside and inside products
  • Data Access Performance value (sec): time needed for the execution of a “cat” command on a full manifest.safe file in Sentinels products
  • Data Access Rate (Mbytes/s): Average data rate, in the case of a full product transfer.
  • Data Access TIFF Rate (Mbytes/s): Average data rate, accessing a full TIFF file within a S1 Level-1 product.
  • Data Access jp2 Rate (Mbytes/s): Average data rate, accessing a full jp2 file within a S-2 product.

Executing the EPM Tool from anyONDA VM, the above performance parameters are measured and are reported in the output file of the script, separately per each Sentinel mission.

For each Sentinel mission, the following is computed, when applicable:

  • Average of 3 Data browsing performance value (sec) checks, performed in random folders listing products.
  • Average of 3 Data browsing performance value (sec) checks, performed within random products.
  • Average of 3 Data Access Performance value (sec) checks, measured on random products.
  • Average of 3 Data Access Rate (Mbytes/s) checks, measured on random products.
  • Average of 3 Data Access TIFF/jp2 Rate (Mbytes/s) checks, measured on random products

Instructions for the usage of EPM Tool are given here below:

usage: epm.py [-h] -m M [-l L] [-o O]

optional arguments:
-h, –help          show this help message and exit
-m M                  Specify the path of the ENS mount point
-l L                      Specify the log file (i.e. path/logfile)
-o O                    Specify the output file (i.e. path/outputfile)

Sample Output Report:

{
   "Description": "E.P.M. ENS Performance Meter",
   "S1": {
      "Data Browsing Performance value (Outside Product)": "0.007798 s",
      "Data Browsing Performance value (Inside Product)": "0.031485 s",
      "Data Access Performance value": "0.138308 s",
      "Data Access Rate (Full Product)": "43.50 Mbyte/s",
      "Data Access Rate (TIFF)": "51.36 Mbyte/s"
   },
   "S2": {
      "Data Browsing Performance value (Outside Product)": "0.047387 s",
      "Data Browsing Performance value (Inside Product)": "0.018768 s",
      "Data Access Performance value": "0.109096 s",
      "Data Access Rate (Full Product)": "43.29 Mbyte/s",
      "Data Access Rate (JP2)": "8.58 Mbyte/s"
   },
   "S3": {
      "Data Browsing Performance value (Outside Product)": "0.007178 s",
      "Data Browsing Performance value (Inside Product)": "3.093074 s",
      "Data Access Performance value": "0.130043 s",
      "Data Access Rate (Full Product)": "43.00 Mbyte/s"
   }
}

As a reference for users’ evaluation of the resulting ENS performances, the following table provides typical values for each performance parameter.

Performance parameterDescriptionValues
Data browsing performance value (sec)Time needed for the execution of a “ls” command5-100 ms (outside products)

 

100-5000 ms (within products)

Data Access Performance value (sec)Time needed for the execution of a “cat” command on a full manifest.safe file included in Sentinels products.100-5000 ms
Data Access Rate (Mbytes/s)Average data rate, in the case of a full product transfer.10-50 Mbytes/s
Data Access TIFF Rate (Mbytes/s)Average data rate, when transferring a full TIFF file from within a Sentinel-1 Level-1 product.10-50 Mbytes/s
Data Access jp2 Rate (Mbytes/s)Average data rate, when transferring a full jp2 file from within a Sentinel-2 product.1-10 Mbytes/s