SAM Doc : SRM

This page last changed on Nov 23, 2010 by kskaburs.

SRM-probe
SRM Metrics
Execution

Locking of working directory

Troubleshooting

SRM-probe

SRM Metrics

Metrics	Description
org.sam.SRM-All	Wrapper metric to launch the other metrics and publish passive checks results to Nagios.
org.sam.SRM-GetSURLs	Get full SRM endpoint(s) and storage areas from BDII.
org.sam.SRM-LsDir	List content of VO's top level space area(s) in SRM.
org.sam.SRM-Put	Copy a local file to the SRM into default space area(s).
org.sam.SRM-Ls	List (previously copied) file(s) on the SRM.
org.sam.SRM-GetTURLs	Get Transport URLs for the file copied to storage.
org.sam.SRM-Get	Copy given remote file(s) from SRM to a local file.
org.sam.SRM-Del	Delete given file(s) from SRM.

Dependency tree for the metrics in org.sam.SRM-probe (launched by org.sam.SRM-All metric):

        1:GetSURLs
         ^     ^
        /       \
   2:LsDir  ____3:Put________
            ^   ^     ^     ^
           /   /       \     \
       4:Ls 5:GetTURLs 6:Get 7:Del

   eg.:
   2:LsDir - "sequence number":"metrics abbreviation"

metrics use file-based IPC to communicate endpoints and other required info between each other. The files are located under metric's working directory: /var/lib/gridprobes/<VO or FQAN>/<namespace>/SRM/<hostname>/

for all metrics except org.sam.SRM-GetTURLs Python lcg_util/gfal API is used. Due to a severe bug (https://gus.fzk.de/ws/ticket_info.php?ticket=63399) in lcg_gt3() C API crashing CPython org.sam.SRM-GetTURLs had to be re-implemented to use lcg-gt CLI.

Execution

Locking of working directory

Time limited metric working directory locking was implemented to eliminate race conditions when metrics are executed too close in time (clashes in scheduling or manual invocations). The file name is lock. Time limit is 5 min. The lock is created by org.sam.SRM-GetSURLs and removed by org.sam.SRM-Del. If by any reason the file was not removed, the directory is considered to be locked until 5 min has passed since the file creation.

Troubleshooting

TODO

Document generated by Confluence on Feb 27, 2014 10:19