[OpenAFS] Client update and failover for afsdb hosts
Steve Simmons
scs@umich.edu
Thu, 22 Aug 2019 15:03:38 -0400
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Awesome, thanks.
Steve
On Thu, Aug 22, 2019 at 2:59 PM Benjamin Kaduk <kaduk@mit.edu> wrote:
> On Thu, Aug 22, 2019 at 02:53:13PM -0400, Steve Simmons wrote:
> > To make a long story short, we're going to be moving the network on which
> > our afsdb servers reside from one data center to another. Trust me, you
> > don't want to know the details. This will required a period of time
> wherein
> > all the current afsdb hosts are down. The fileservers will not be
> affected.
> >
> > To minimize the pain during the transition, we're temporarily adding a
> > fourth non-voting server and updating CellServDB files appropriately.
> Some
> > questions have come up about how the clients will react to this change
> and
> > the best strategy to pursue for them. Complicating this are clients
> running
> > various versions of openafs, most of which are recent 1.6/1.8, but there
> > are a few 1.4.14/15 clients out there. All the clients referred to here
> are
> > running various flavors of Linux. Yeah, I could read the code for all
> > those versions, but in case someone happens to know:
> >
> > Does a client read the CellServDB only at startup? Can it be forced to
> > re-read it without a restart?
> >
> > If a CellServDB contains multiple entries (4) for a given cell, does the
> > client process them in any particular order (round robin, random, other)?
> > If some are non-responsive, will the client give preference to the
> others?
>
> Look at fs newcell and fs setserverprefs.
>
> -Ben
>
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<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-family:arial,he=
lvetica,sans-serif">Awesome, thanks.</div><div class=3D"gmail_default" styl=
e=3D"font-family:arial,helvetica,sans-serif"><br></div><div><div dir=3D"ltr=
" class=3D"gmail_signature" data-smartmail=3D"gmail_signature"><div dir=3D"=
ltr"><div>Steve</div></div></div></div></div><br><div class=3D"gmail_quote"=
><div dir=3D"ltr" class=3D"gmail_attr">On Thu, Aug 22, 2019 at 2:59 PM Benj=
amin Kaduk <<a href=3D"mailto:kaduk@mit.edu">kaduk@mit.edu</a>> wrote=
:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.=
8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Thu, Aug 22=
, 2019 at 02:53:13PM -0400, Steve Simmons wrote:<br>
> To make a long story short, we're going to be moving the network o=
n which<br>
> our afsdb servers reside from one data center to another. Trust me, yo=
u<br>
> don't want to know the details. This will required a period of tim=
e wherein<br>
> all the current afsdb hosts are down. The fileservers will not be affe=
cted.<br>
> <br>
> To minimize the pain during the transition, we're temporarily addi=
ng a<br>
> fourth non-voting server and updating CellServDB files appropriately. =
Some<br>
> questions have come up about how the clients will react to this change=
and<br>
> the best strategy to pursue for them. Complicating this are clients ru=
nning<br>
> various versions of openafs, most of which are recent 1.6/1.8, but the=
re<br>
> are a few 1.4.14/15 clients out there. All the clients referred to her=
e are<br>
> running various flavors of Linux. Yeah, I could read the code=C2=A0 fo=
r all<br>
> those versions, but in case someone happens to know:<br>
> <br>
> Does a client read the CellServDB only at startup? Can it be forced to=
<br>
> re-read it without a restart?<br>
> <br>
> If a CellServDB contains multiple entries (4) for a given cell, does t=
he<br>
> client process them in any particular order (round robin, random, othe=
r)?<br>
> If some are non-responsive, will the client give preference to the oth=
ers?<br>
<br>
Look at fs newcell and fs setserverprefs.<br>
<br>
-Ben<br>
</blockquote></div>
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