[OpenAFS] ForwardMulti sessions

Derrick Brashear shadow@gmail.com
Wed, 18 Sep 2013 08:10:26 -0400


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In general, you can't. that's to ensure not all the replicas are offline at
once.

However, vos release has the -stayonline switch, which will do them all in
parallel...
it changes the order of how refreshed replicas come online,
instead of a small number at a time until they are done, all the data is
moved, and then the replicas
all come online at the same time.



On Wed, Sep 18, 2013 at 4:13 AM, Antony Mayi <antonymayi@yahoo.com> wrote:

> Hi,
>
> When releasing a volume I can see it starting an operation called
> ForwardMulti. I have 5 remote replicas for a volume and it seems to start
> three ForwardMulti sessions (two with single replica fileserver (ro3, ro5)
> and 1 with three (ro1 + ro2 + ro4)). Based on the observation (see the
> release report at the bottom) the sessions are started in sequence and all
> replications within same session run in parallel. If each individual
> replication operation takes T_repl time it means each ForwardMulti session
> also takes T_repl time and in my case the whole release operation takes
> 3*T_repl time. That makes me to think that it could have taken only
> 1*T_repl time had all the replications been made within single ForwardMulti
> session.
>
> I don't seem to be able to find any information about what the ForwardMulti
> is and why some replications are made within single ForwardMulti session
> and others in separate ones. Just to give some background all the roX
> fileservers are in same rack, on same network.
>
> How can I make all the replication to run within single ForwardMulti
> session?
>
> Thanks,
> Antony.
>
>
> The typical release in my case produces following report:
>
> /usr/sbin/vos release proj.prj1 -verbose
> proj.prj1
>     RWrite: 536871449     ROnly: 536871450     Backup: 536871451
>     number of sites -> 7
>        server rw1 partition /vicepa RW Site
>        server rw1 partition /vicepa RO Site
>        server ro5 partition /vicepa RO Site
>        server ro1 partition /vicepa RO Site
>        server ro4 partition /vicepa RO Site
>        server ro2 partition /vicepa RO Site
>        server ro3 partition /vicepa RO Site
> This is a complete release of volume 536871449
> Re-cloning permanent RO volume 536871450 ... done
> Getting status of parent volume 536871449... done
> Starting transaction on RO clone volume 536871450... done
> Setting volume flags for volume 536871450... done
> Ending transaction on volume 536871450... done
> Replacing VLDB entry for proj.prj1... done
> Starting transaction on cloned volume 536871450... done
> Updating existing ro volume 536871450 on ro5 ...
> Starting ForwardMulti from 536871450 to 536871450 on ro5 (as of Wed Sep 18
> 08:23:33 2013).
> Updating existing ro volume 536871450 on ro1 ...
> Updating existing ro volume 536871450 on ro4 ...
> Updating existing ro volume 536871450 on ro2 ...
> Starting ForwardMulti from 536871450 to 536871450 on ro1 and ro4 and ro2
> (as of Wed Sep 18 08:23:33 2013).
> Updating existing ro volume 536871450 on ro3 ...
> Starting ForwardMulti from 536871450 to 536871450 on ro3 (as of Wed Sep 18
> 08:23:33 2013).
> updating VLDB ... done
> Released volume proj.prj1 successfully
>
>


-- 
Derrick

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<div dir=3D"ltr"><div><div>In general, you can&#39;t. that&#39;s to ensure =
not all the replicas are offline at once.<br><br></div>However, vos release=
 has the -stayonline switch, which will do them all in parallel... <br>it c=
hanges the order of how refreshed replicas come online,<br>
</div>instead of a small number at a time until they are done, all the data=
 is moved, and then the replicas<br>all come online at the same time.<br><b=
r></div><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On We=
d, Sep 18, 2013 at 4:13 AM, Antony Mayi <span dir=3D"ltr">&lt;<a href=3D"ma=
ilto:antonymayi@yahoo.com" target=3D"_blank">antonymayi@yahoo.com</a>&gt;</=
span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div><div style=3D"font-size:12pt;font-famil=
y:times new roman,new york,times,serif"><div style=3D"font-family:&#39;time=
s new roman&#39;,&#39;new york&#39;,times,serif;font-size:12pt">
Hi,</div><div style=3D"font-family:&#39;times new roman&#39;,&#39;new york&=
#39;,times,serif;font-size:12pt"><br></div><div style=3D"font-style:normal;=
font-size:16px;background-color:transparent;font-family:&#39;times new roma=
n&#39;,&#39;new york&#39;,times,serif">
When releasing a volume I can see it starting an operation called ForwardMu=
lti. I have 5 remote replicas for a volume and it seems to start three Forw=
ardMulti sessions (two with single replica fileserver (ro3, ro5) and 1 with=
 three (ro1 + ro2 + ro4)). Based on the observation (see the release report=
 at the bottom) the sessions are started in sequence and all replications w=
ithin same session run in parallel. If each individual replication operatio=
n takes T_repl time it means each
 ForwardMulti session also takes T_repl time and in my case the whole relea=
se operation takes 3*T_repl time. That makes me to think that it could have=
 taken only 1*T_repl time had all the replications been made within single =
ForwardMulti session.</div>
<div style=3D"font-style:normal;font-size:16px;background-color:transparent=
;font-family:&#39;times new roman&#39;,&#39;new york&#39;,times,serif"><br>=
</div><div style=3D"font-style:normal;font-size:16px;background-color:trans=
parent;font-family:&#39;times new roman&#39;,&#39;new york&#39;,times,serif=
">
I don&#39;t seem to be able to find any information about what the=A0<span =
style=3D"font-size:12pt">ForwardMulti is and why some replications are made=
 within single=A0</span><span style=3D"font-size:12pt">ForwardMulti session=
 and others in separate ones. Just to give some background all the roX file=
servers are in same rack, on same network.</span></div>
<div style=3D"font-style:normal;font-size:12pt;background-color:transparent=
;font-family:&#39;times new roman&#39;,&#39;new york&#39;,times,serif"><spa=
n style=3D"font-size:12pt"><br></span></div><div style=3D"font-size:16px;fo=
nt-style:normal;background-color:transparent;font-family:&#39;times new rom=
an&#39;,&#39;new york&#39;,times,serif">
<span style=3D"font-size:12pt">How can I make all the replication to run wi=
thin single=A0</span>ForwardMulti session?</div><div style=3D"font-size:12p=
t;font-style:normal;background-color:transparent;font-family:&#39;times new=
 roman&#39;,&#39;new york&#39;,times,serif">
<br></div><div style=3D"font-size:16px;font-style:normal;background-color:t=
ransparent;font-family:&#39;times new roman&#39;,&#39;new york&#39;,times,s=
erif">Thanks,</div><div style=3D"font-size:16px;font-style:normal;backgroun=
d-color:transparent;font-family:&#39;times new roman&#39;,&#39;new york&#39=
;,times,serif">
Antony.</div><div style=3D"font-style:normal;font-size:16px;background-colo=
r:transparent;font-family:&#39;times new roman&#39;,&#39;new york&#39;,time=
s,serif"><span style=3D"font-size:12pt"><br></span></div><div style=3D"font=
-style:normal;font-size:16px;background-color:transparent;font-family:&#39;=
times new roman&#39;,&#39;new york&#39;,times,serif">
<span style=3D"font-size:12pt"><br></span></div><div style=3D"font-style:no=
rmal;font-size:16px;background-color:transparent;font-family:&#39;times new=
 roman&#39;,&#39;new york&#39;,times,serif"><span style=3D"font-size:12pt">=
The typical release in my case produces following report:</span></div>
<div style=3D"font-style:normal;font-size:12pt;background-color:transparent=
;font-family:&#39;times new roman&#39;,&#39;new york&#39;,times,serif"><spa=
n style=3D"font-size:12pt"><br></span></div><div style=3D"background-color:=
transparent">
<font face=3D"times
 new roman, new york, times, serif">/usr/sbin/vos release proj.prj1 -verbos=
e</font></div><div style=3D"background-color:transparent"><font face=3D"tim=
es new roman, new york, times, serif">proj.prj1=A0</font></div><div style=
=3D"background-color:transparent">
<font face=3D"times new roman, new york, times, serif">=A0 =A0 RWrite: 5368=
71449 =A0 =A0 ROnly: 536871450 =A0 =A0 Backup: 536871451=A0</font></div><di=
v style=3D"background-color:transparent"><font face=3D"times new roman, new=
 york, times, serif">=A0 =A0 number of sites -&gt; 7</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">=A0 =A0 =A0 =A0server rw1 partition /vicepa RW Site=
=A0</font></div><div style=3D"background-color:transparent"><font face=3D"t=
imes new roman, new york, times, serif">=A0 =A0 =A0 =A0server rw1 partition=
 /vicepa RO Site=A0</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">=A0 =A0 =A0 =A0server ro5 partition /vicepa RO Site=
=A0</font></div><div style=3D"background-color:transparent"><font face=3D"t=
imes new roman, new york, times, serif">=A0 =A0 =A0 =A0server ro1 partition=
 /vicepa RO Site=A0</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">=A0 =A0 =A0 =A0server ro4 partition /vicepa RO Site=
=A0</font></div><div style=3D"background-color:transparent"><font face=3D"t=
imes new roman, new york, times, serif">=A0 =A0 =A0 =A0server ro2 partition=
 /vicepa RO Site=A0</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">=A0 =A0 =A0 =A0server ro3 partition /vicepa RO Site=
=A0</font></div><div style=3D"background-color:transparent"><font face=3D"t=
imes new roman, new york, times, serif">This
 is a complete release of volume 536871449</font></div><div style=3D"backgr=
ound-color:transparent"><font face=3D"times new roman, new york, times, ser=
if">Re-cloning permanent RO volume 536871450 ... done</font></div><div styl=
e=3D"background-color:transparent">
<font face=3D"times new roman, new york, times, serif">Getting status of pa=
rent volume 536871449... done</font></div><div style=3D"background-color:tr=
ansparent"><font face=3D"times new roman, new york, times, serif">Starting =
transaction on RO clone volume 536871450... done</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">Setting volume flags for volume 536871450... done</=
font></div><div style=3D"background-color:transparent"><font face=3D"times =
new roman, new york, times, serif">Ending transaction on volume 536871450..=
. done</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">Replacing VLDB
 entry for proj.prj1... done</font></div><div style=3D"background-color:tra=
nsparent"><font face=3D"times new roman, new york, times, serif">Starting t=
ransaction on cloned volume 536871450... done</font></div><div style=3D"bac=
kground-color:transparent">
<font face=3D"times new roman, new york, times, serif">Updating existing ro=
 volume 536871450 on ro5 ...</font></div><div style=3D"background-color:tra=
nsparent"><font face=3D"times new roman, new york, times, serif">Starting F=
orwardMulti from 536871450 to 536871450 on ro5 (as of Wed Sep 18 08:23:33 2=
013).</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">Updating existing ro volume 536871450 on ro1 ...</f=
ont></div><div style=3D"background-color:transparent"><font face=3D"times n=
ew roman, new york, times, serif">Updating existing ro volume 536871450 on =
ro4 ...</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york,
 times, serif">Updating existing ro volume 536871450 on ro2 ...</font></div=
><div style=3D"background-color:transparent"><font face=3D"times new roman,=
 new york, times, serif">Starting ForwardMulti from 536871450 to 536871450 =
on ro1 and ro4 and ro2 (as of Wed Sep 18 08:23:33 2013).</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">Updating existing ro volume 536871450 on ro3 ...</f=
ont></div><div style=3D"background-color:transparent"><font face=3D"times n=
ew roman, new york, times, serif">Starting ForwardMulti from 536871450 to 5=
36871450 on ro3 (as of Wed Sep 18 08:23:33 2013).</font></div>
<div style=3D"background-color:transparent"><font face=3D"times new roman, =
new york, times, serif">updating VLDB ... done</font></div><div style=3D"ba=
ckground-color:transparent"><font face=3D"times new roman, new york, times,=
 serif">Released volume proj.prj1 successfully</font></div>
<div><br></div></div></div></blockquote></div><br><br clear=3D"all"><br>-- =
<br>Derrick
</div>

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