<font size=2 face="sans-serif">Hello Kristy,</font>
<br>
<br><font size=2 face="sans-serif">The GPFSFileSystemAPI and GPFSNodeAPI
sensor metrics are from the point of view of "applications" in
the sense that they provide stats about I/O requests made to files in GPFS
file systems from user level applications using POSIX interfaces like open(),
close(), read(), write(), etc.</font>
<br>
<br><font size=2 face="sans-serif">This is in contrast to similarly named
sensors without the "API" suffix, like GPFSFilesystem and GPFSNode.
Those sensors provide stats about I/O requests made by the GPFS code
to NSDs (disks) making up GPFS file systems.</font>
<br>
<br><font size=2 face="sans-serif">The relationship between application
I/O and disk I/O might or might not be obvious. Consider some examples.
An application that starts sequentially reading a file might, at
least initially, cause more disk I/O than expected because GPFS has decided
to prefetch data. An application write() might not immediately cause
a the writing of disk blocks due to the operation of the pagepool. Ultimately,
application write()s might cause twice as much data written to disk due
to the replication factor of the file system. Application I/O concerns
itself with user data; disk I/O might have to occur to handle the user
data and associated file system metadata (like inodes and indirect blocks).</font>
<br>
<br><font size=2 face="sans-serif">The difference between GPFSFileSystemAPI
and GPFSNodeAPI: GPFSFileSystemAPI reports stats for application I/O per
filesystem per node; GPFSNodeAPI reports application I/O stats per node.
Similarly, GPFSFilesystem reports stats for disk I/O per filesystem
per node; GPFSNode reports disk I/O stats per node.</font>
<br>
<br><font size=2 face="sans-serif">I hope this helps.</font>
<br><font size=2 face="sans-serif">Eric Agar</font>
<br>
<br>
<br><font size=2 face="sans-serif">Regards, The Spectrum Scale (GPFS) team<br>
<br>
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<br>
<br>
<br>
<br><font size=1 color=#5f5f5f face="sans-serif">From:
</font><font size=1 face="sans-serif">"Oesterlin, Robert"
<Robert.Oesterlin@nuance.com></font>
<br><font size=1 color=#5f5f5f face="sans-serif">To:
</font><font size=1 face="sans-serif">gpfsug main discussion
list <gpfsug-discuss@spectrumscale.org></font>
<br><font size=1 color=#5f5f5f face="sans-serif">Date:
</font><font size=1 face="sans-serif">06/12/2017 04:43 PM</font>
<br><font size=1 color=#5f5f5f face="sans-serif">Subject:
</font><font size=1 face="sans-serif">Re: [gpfsug-discuss]
Meaning of API Stats Category</font>
<br><font size=1 color=#5f5f5f face="sans-serif">Sent by:
</font><font size=1 face="sans-serif">gpfsug-discuss-bounces@spectrumscale.org</font>
<br>
<hr noshade>
<br>
<br>
<br><font size=2 face="Calibri">Hi Kristy</font>
<br><font size=2 face="Calibri"> </font>
<br><font size=2 face="Calibri">What I *think* the difference is:</font>
<br><font size=2 face="Calibri"> </font>
<br><font size=2 face="Calibri">gpfs_fis: - calls to the GPFS file system
interface</font>
<br><font size=2 face="Calibri">gpfs_fs: calls from the node that actually
make it to the NSD server/metadata</font>
<br><font size=2 face="Calibri"> </font>
<br><font size=2 face="Calibri">The difference being what\u2019s served out
of the local node pagepool.</font>
<br><font size=2 face="Calibri"> </font>
<br><font size=2 face="Calibri">Bob Oesterlin<br>
Sr Principal Storage Engineer, Nuance<br>
</font>
<br><font size=2 face="Calibri"> </font>
<br><font size=3 face="Calibri"><b>From: </b><gpfsug-discuss-bounces@spectrumscale.org>
on behalf of Kristy Kallback-Rose <kkr@lbl.gov><b><br>
Reply-To: </b>gpfsug main discussion list <gpfsug-discuss@spectrumscale.org><b><br>
Date: </b>Monday, June 12, 2017 at 3:17 PM<b><br>
To: </b>gpfsug main discussion list <gpfsug-discuss@spectrumscale.org><b><br>
Subject: </b>[EXTERNAL] [gpfsug-discuss] Meaning of API Stats Category</font>
<br><font size=2 face="Calibri"> </font>
<br><font size=2 face="Calibri">Hi, </font>
<br><font size=2 face="Calibri"> </font>
<br><font size=2 face="Calibri"> Can anyone provide more detail about
what is meant by the following two categories of stats? The PDG has a limited
description as far as I could see. I'm not sure what is meant by Application
PoV. Would the Grafana bridge count as an "application"?</font>
<br><font size=2 face="Calibri"> </font>
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