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Command Line Tool

usage: edg-replica-manager getAccessCost [options]
Get the access cost of the cheapest replicas for each LFN at each CE site.
 -d,--computing-elements <ceID>   The destination Computing Elements.
 -l,--logical-file-names <file>   The logical file names
 -p,--protocol <protocol>         The protocol to be used for transfer.
                                  Defaults to gsiftp.

Calculate the expected file access cost for each CE to access the set of LFNs. It makes the assumptions that no replication occurs. The -l and -d options are mandatory.

Semantics

Firstly each LFN is resolved into a list of SURLs using the listReplicas command. Then for each CE the set of best replicas for it to access is found using listBestFile for each LFN. The access cost for all the best replicas is summed up to give a total estimated access cost for each CE to access the full set of LFNs.

The access-cost array is returned, which is then printed on screen, with the best SURL for each LFN at each CE, with the corresponding estimated time to actually copy the files to local store.

Arguments

no arguments.

Options

computing-elements
A list of valid CE IDs.
logical-file-names
A list of valid LFNs or GUIDs.
protocol
The protocol to be used. If it is omitted, the default protocol used, currently GridFTP.

Return value

The call returns 0 on success and -1 on failure. It prints the access cost to stdout, grouped by CEs and sub-grouped by LFNs.

Example:

Access Cost 0 :
CE = lxshare0286.cern.ch:2119/jobmanager-pbs-short
Best Files:
0:srm://lxshare0291.cern.ch/flatfiles/file-1
Total Access Time = 0.0

Access Cost 1 :
CE = grid01.ph.gla.ac.uk:2119/jobmanager-pbs-short
Best Files:
0:srm://lxshare0291.cern.ch/flatfiles/file-1
Total Access Time = 10.0

For the CE at CERN, the access cost is zero since the best replica is located on the same site. Since the best replica for the CE at Glasgow is still the replica at CERN the estimated access cost for the file according to the network information provider is 10s. Using these results, a user would be most likely to submit their job to the CE at CERN.

Errors

The call can fail for many reasons. Some of the reasons are:


next up previous contents
Next: File Transfer Commands Up: Optimization Commands Previous: getAccessCost   Contents
2005-02-04