LFN to PFN AlgorithmΒΆ

Gravitational wave frame files follow the naming convention ::

  • Observatory from which data is taken. E.g., H (Hanford), L (Livingston), V (Virgo), G (GEO600), K (KAGRA).

  • Frame type: description of instrument and data reduction level / calibration version. E.g., H1_HOFT_C00.

  • Epoch: GPS start time of data in frame file.

  • Duration: number of seconds of data.

In rucio, the names of files, datasets and containers (collections of data objects) are composed of two strings: the scope and a name. The combination of both is called a data identifier (DID). For instance a file identifier (logical filename, LFN) is composed of a scope and a file name like scope:name. For gravitational wave data we adopt the convention:

  • Scope: observing epoch.

  • Name: LFN of file

Example: the frame file L-L1_HOFT_C01-1164513280-4096.gwf (calibration level-1 Livingston strain data taken during the 10th engineering run, ER10), appears in rucio simply as ER10:L-L1_HOFT_C01-1164513280-4096.gwf.

The path to files on storage (physical filename, PFN) follows a deterministic algorithm whereby the PFN is determined directly from the LFN and a site-specific prefix.

Note that some data types (e.g., Virgo data, raw frames and C00 frame types) have followed slightly different PFN conventions, requiring some exeptions to be built into our LFN2PFN algorithm.

Examples of LFN->PFN conversion:

LFN Epoch/Scope PFN DID
H-H1_HOFT_C01-1188003840-4096.gwf O2 /hdfs/frames/O2/hoft_C01/H1/H-H1_HOFT_C01-11880/H-H1_HOFT_C01-1188003840-4096.gwf O2:H-H1_HOFT_C01-1188003840-4096.gwf
L-L1_HOFT_C00-1158533120-4096.gwf postO1 /hdfs/frames/postO1/hoft/L1/L-L1_HOFT_C00-11585/L-L1_HOFT_C00-1158533120-4096.gwf postO1:L-L1_HOFT_C00-1158533120-4096.gwf
V-V1Online-1192294000-2000.gwf AdVirgo /hdfs/frames/AdVirgo/HrecOnline/V-V1Online-11922/V-V1Online-1192294000-2000.gwf AdVirgo:V-V1Online-1192294000-2000.gwf
H-H1_R-1126631040-64.gwf O1 /hdfs/frames/O1/raw/H1/H-H1_R-11266/H-H1_R-1126631040-64.gwf O1::H-H1_R-1126631040-64.gwf