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<div class="moz-cite-prefix">On 04/09/2015 07:26 PM, Eric Mortensen
wrote:<br>
</div>
<blockquote
cite="mid:CAHRqbZFB3uEdSyaMvYSyabn3Rp91N483en6jG0Cphc9say1_qw@mail.gmail.com"
type="cite">
<div dir="ltr">Yes that is correct, read from a different mount
(different brick/server). The error from the app server when
reading is that the file was not found. (The actual error from
the OS which leads to the 404 error from the app server is not
visible, I will try and log it. I am pretty sure the OS error is
file not found, though.)
<div><br>
</div>
<div>The fact that if I add a 1 second wait in the (automated)
test client between create and read, then everything is fine,
that is what leads me to believe that the problem is that the
second server (where the read happens) has not been
synchronized with the first server. </div>
<div><br>
</div>
<div>But this would make no sense if the replication is
synchronous, no?</div>
</div>
</blockquote>
+gluster-users<br>
<br>
hi Eric,<br>
Replication is synchronous, but there are performance
translators like write-behind which keep the written data in memory
before flushing to the replication module which in turn send the
data to the respective bricks synchronously. One more question, are
the app servers accessing the files directly through the backend
filesystem or using a gluster mount?<br>
<br>
Pranith<br>
<blockquote
cite="mid:CAHRqbZFB3uEdSyaMvYSyabn3Rp91N483en6jG0Cphc9say1_qw@mail.gmail.com"
type="cite">
<div dir="ltr">
<div><br>
</div>
<div>Eric Mortensen</div>
<div>Appstax Technologies</div>
<div>
<div><br>
</div>
<div> </div>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Thu, Apr 9, 2015 at 3:32 PM, Pranith
Kumar Karampuri <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:pkarampu@redhat.com" target="_blank">pkarampu@redhat.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div>
<div class="h5"> <br>
<div>On 04/09/2015 04:39 PM, Eric Mortensen wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">We have a Gluster replicated setup
with 2 servers. Each server also runs an app
server that functions as a client of the gluster
files. Client access to the appservers are load
balanced using round robin.
<div><br>
</div>
<div>Sometimes, when a client creates a new file
and then immediately tries to read it, the read
fails because the appserver cannot find it. If
the client sleeps for about 1 second between
creating the file and reading it, the read
always succeeds. </div>
<div><br>
</div>
<div>I was under the impression that gluster
replication was synchrounous, so the appserver
would not return back to the client until the
created file was replicated to the other server.
But this does not seem to be the case, because
sleeping a little bit always seems to make the
read failures go away. Is there any other reason
why a file created is not immediately available
on a second request? </div>
<div><br>
</div>
<div>I am running 3.6.2 and have not configured
anything special except storage.owner-id and
auth.allow.</div>
</div>
</blockquote>
<br>
</div>
</div>
If I understand correctly, creates are happening from one
mount and reads are happening from another mount?<br>
<br>
What do you mean by read failing? Does it give any error?
or the data read is not complete?<br>
<br>
Pranith<br>
<blockquote type="cite"><span class="">
<div dir="ltr">
<div><br>
</div>
<div>Thanks!</div>
<div>Eric Mortensen</div>
<div>Appstax Technologies</div>
</div>
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