Hi XRootd Community,
We here at DESY were working on interfacing XRootd with dCache.
Currently we need the stage-in capability from dCache (which in this
case is MSS) into XRootd local folder.
And also we need a Migration tool from XRootd local folder into MSS
(dCache). We use the oss.msgwcmd and
oss.stagecmd directives. Also the oss.rcreate directive is set. Well,
whenever the StageIn command is called everything works
fine and the files are staged ok. But we have some problems with
Flushing files to MSS.
Calling "msstalk create mssfn mode" in the most straightforward way does
not work.
It seems to us that
1. The "create" command is called BEFORE the actual file was written
into the local folder by xrdcp. So there is nothing to flush.
2. It is kind of unknown when the file should be start to being flushed.
3. "create" should first touch the file on MSS, return "0" saying that
evrything is ok and then it can actually flush the file. Otherwise the
flushing does not work.
So we wonder how actually the create should function and how it should
communicate with XRootd?
What kind of logic should be behind the implementation of create part of
oss.mssgwcmd command?
Volodymyr Kapchynskyy,
DESY
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