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Hi all,

After upgrading our external (memory caching) proxies to XRootD 5, we was spotted that some of our internal monitoring is showing less data transferred than expected in some cases. Our monitoring uses the f-stream, and is mostly just consuming the f-stream close messages XFR and OPS sections, along with other messages needed to make sense of them (user connections, fstream opens).

I tracked it down to our XRootD 5 gateways serving some reads as pgreads (specifically, reads from offsite XCaches). I don’t fully understand what pgreads are[1], but I think the change in reporting comes from the fact that previously, our XRootD 4 gateways did not support pgreads, so the pgreads fell back to reads, which then contributed to the XFR ‘read’ total in the close message. Now the gateways are serving pgreads, and I can’t work out how to get the pgread summary stats. As far as I can tell, pgread operations don’t contribute to any XFR or OPS counters in the f-stream close messages.

Is there a setting I’m missing when specifying the monitoring directive[2], or have I missed a f-stream datagram format change that adds pgread stats? Or alternatively, have I completely misunderstood what is going on here?

Thanks,

Tom

[1] I think they are some sort of paged read that can make use of consistency checking ‘per page’ if the server supports it, but I may be completely off the mark here…

[2] We currently use these monitoring directives:

xrootd.monitor all auth fstat 10s ops lfn xfr 5 ident 5m dest fstat info user redir HOST:PORT

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