Summary file
The summary file tracks global properties of a dataset, such as dataset id, its size, the total number of files, and the time it was created. It is stored in the dataset directory on the parallel file system. Internally, the data of the summary file is organized as a hash. Here are the contents of an example summary file.
VERSION
6
COMPLETE
1
DSET
ID
18
NAME
scr.dataset.18
CREATED
1312853507675143
USER
user1
JOBNAME
simulation123
JOBID
112573
CKPT
18
FILES
4
SIZE
2097182
COMPLETE
1
The VERSION
field records the version number of file format of the
summary file. This enables future SCR implementations to change the
format of the summary file while still allowing SCR to read summary
files written by older implementations.
A COMPLETE
flag concisely denotes whether all files for this dataset
are thought to be valid. The properties of the dataset are then
contained within the DSET
hash.
When fetching a checkpoint upon a restart, rank 0 reads the summary file and broadcasts its contents to the other ranks.