[omniORB] How can I creat a hot-standby name service?
zlr
zhanglr@stee.com.sg
Tue Jul 23 03:20:01 2002
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Hi:
At first, Duncan and Lars thank you for your suggestion.
About the suggestion form Lars:
I have tried to set the same OMNINAMES_LOGDIR path in two pcs where =
I
have installed NameService. But I found, when NameService started, it =
will
create two files (one is *.log, another is *.bak). They is both include =
the
PC name in their file name. ( E.g. I have tow PC--PC1 as master and PC2 =
as
slave in hot-standby. it will create four files --omninames-PC1.log,
omninames-PC1.bak and omninames-PC2.log, omninames-PC2.bak).
And I also try to synchronization these files. I rename the
omninames-PC1.log to omninames-PC2.log and omninames-PC1. bak to
omninames-PC2.bak. But I found the NameService cannot be started in PC2.
About the suggestion form Duncan:
Now I am using omniORB 3.0:
As you say: In omniORB 3.0, there's no option but to make the
applications aware of the situation and have them retry if they get
COMM_FAILUREs.
But my problem is the server is running. And the server is also =
include
Messaging Server, Routing Server ...besides Database Server. They are
running on different PCs with the PC where Database Server (Name =
Servcie) is
running.
And I am not sure the two Hot-standby Name Service PC (PC1 and PC2) =
will
be both started before all servers running. So I cannot register server =
in
two NameServices.
But if I register the servers to another NameService (PC2) after
swiching over. Do I have to restart all servers (Messaging Server, =
Routing
Server ...)?
Best Regards
ZHANG Liren
-------------------------------------------------------------------------=
---
Singapore Technologies Electronics Ltd.
Product Development & Management Division (PDMD)
(65) 413 1613 (Direct)
zhanglr@stee.com.sg
----- Original Message -----
From: "Lars von Wedel" <vonWedel@lfpt.rwth-aachen.de>
To: <omniorb-list@realvnc.com>
Sent: Monday, July 22, 2002 11:26 PM
Subject: Re: [omniORB] How can I creat a hot-standby name service?
>
>
> Duncan,
>
> I may lack some understanding here, but I doubt this will work
> because I see no synchronization between the two name servers'
> log files?
>
> I guess some kind of synchronization or access to
> the same log files via some network file system would be
> required in addition?
>
> Lars
>
>
> Duncan Grisby wrote:
> >
> > On Monday 22 July, "zlr" wrote:
> >
> > > This is a multi-part message in MIME format.
> >
> > Please don't send HTML mail to the mailing list.
> >
> > > In our project, we want to install name service and Database =
in
same
> > > pc.
> > > The problem is our database can suppore hot standby. If the
Database
> > > is switch over( the name service also switch over to another PC ), =
the
> > > new client will cannot connect to server which is running.
> > >
> > > Who can tell me how can I resolve this problem?
> >
> > If you are using omniORB 4.0, you can create a reference to the =
naming
> > service that contains multiple addresses, with a URI like
> > "corbaname::1.2@first.host.name,:1.2@second.host.name". The 1.2
> > version selection is important, since 1.0 doesn't support the
> > alternate addresses.
> >
> > If you do that, omniORB will transparently fall over to using the
> > second address if the first one fails (and go back to the first one =
if
> > the second one fails, and so on...).
> >
> > If you want all the NamingContexts within the name service to =
publish
> > both addresses, look into the endPointNoPublish option.
> >
> > In omniORB 3.0, there's no option but to make the applications aware
> > of the situation and have them retry if they get COMM_FAILUREs.
> >
> > Cheers,
> >
> > Duncan.
> >
> > --
> > -- Duncan Grisby --
> > -- duncan@grisby.org --
> > -- http://www.grisby.org --
> > _______________________________________________
> > omniORB-list mailing list
> > omniORB-list@realvnc.com
> > http://www.realvnc.com/mailman/listinfo/omniorb-list
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<BODY bgColor=3D#ffffff>Hi:<BR> At first, Duncan and =
Lars thank=20
you for your suggestion.<BR><BR> About the suggestion =
form=20
Lars:<BR> I have tried to set the same =
OMNINAMES_LOGDIR path=20
in two pcs where I<BR>have installed NameService. But I found, when =
NameService=20
started, it will<BR>create two files (one is *.log, another is *.bak). =
They is=20
both include the<BR>PC name in their file name. ( E.g. I have tow =
PC--PC1 as=20
master and PC2 as<BR>slave in hot-standby. it will create four files=20
--omninames-PC1.log,<BR>omninames-PC1.bak and omninames-PC2.log,=20
omninames-PC2.bak).<BR><BR> And I also try to =
synchronization=20
these files. I rename the<BR>omninames-PC1.log to omninames-PC2.log and=20
omninames-PC1. bak to<BR>omninames-PC2.bak. But I found the NameService =
cannot=20
be started in PC2.<BR><BR> About the suggestion form=20
Duncan:<BR> Now I am using omniORB =
3.0:<BR> =20
As you say: In omniORB 3.0, there's no option but to make =
the<BR>applications=20
aware of the situation and have them retry if they=20
get<BR>COMM_FAILUREs.<BR> But my problem is the server =
is=20
running. And the server is also include<BR>Messaging Server, Routing =
Server=20
...besides Database Server. They are<BR>running on different PCs with =
the PC=20
where Database Server (Name Servcie) =
is<BR>running.<BR> And I=20
am not sure the two Hot-standby Name Service PC (PC1 and PC2) will<BR>be =
both=20
started before all servers running. So I cannot register server =
in<BR>two=20
NameServices.<BR> But if I register the servers to =
another=20
NameService (PC2) after<BR>swiching over. Do I have to restart all =
servers=20
(Messaging Server, Routing<BR>Server ...)?<BR><BR>Best Regards<BR>ZHANG=20
Liren<BR>----------------------------------------------------------------=
------------<BR><BR>Singapore=20
Technologies Electronics Ltd.<BR>Product Development & Management =
Division=20
(PDMD)<BR>(65) 413 1613 (Direct)<BR><A=20
href=3D"mailto:zhanglr@stee.com.sg">zhanglr@stee.com.sg</A><BR><BR>----- =
Original=20
Message -----<BR>From: "Lars von Wedel" <<A=20
href=3D"mailto:vonWedel@lfpt.rwth-aachen.de">vonWedel@lfpt.rwth-aachen.de=
</A>><BR>To:=20
<<A=20
href=3D"mailto:omniorb-list@realvnc.com">omniorb-list@realvnc.com</A>>=
<BR>Sent:=20
Monday, July 22, 2002 11:26 PM<BR>Subject: Re: [omniORB] How can I creat =
a=20
hot-standby name service?<BR><BR><BR>><BR>><BR>>=20
Duncan,<BR>><BR>> I may lack some understanding here, but I doubt =
this=20
will work<BR>> because I see no synchronization between the two name=20
servers'<BR>> log files?<BR>><BR>> I guess some kind of =
synchronization=20
or access to<BR>> the same log files via some network file system =
would=20
be<BR>> required in addition?<BR>><BR>> =
Lars<BR>><BR>><BR>>=20
Duncan Grisby wrote:<BR>> ><BR>> > On Monday 22 July, "zlr"=20
wrote:<BR>> ><BR>> > > This is a multi-part message in =
MIME=20
format.<BR>> ><BR>> > Please don't send HTML mail to the =
mailing=20
list.<BR>> ><BR>> > > In our =
project, we=20
want to install name service and Database in<BR>same<BR>> > >=20
pc.<BR>> > > The problem is our =
database can=20
suppore hot standby. If the<BR>Database<BR>> > > is switch =
over( the=20
name service also switch over to another PC ), the<BR>> > > new =
client=20
will cannot connect to server which is running.<BR>> > =
><BR>> >=20
> Who can tell me how can I resolve this=20
problem?<BR>> ><BR>> > If you are using omniORB 4.0, you can =
create=20
a reference to the naming<BR>> > service that contains multiple =
addresses,=20
with a URI like<BR>> >=20
"corbaname::1.2@first.host.name,:1.2@second.host.name". The 1.2<BR>> =
>=20
version selection is important, since 1.0 doesn't support the<BR>> =
>=20
alternate addresses.<BR>> ><BR>> > If you do that, omniORB =
will=20
transparently fall over to using the<BR>> > second address if the =
first=20
one fails (and go back to the first one if<BR>> > the second one =
fails,=20
and so on...).<BR>> ><BR>> > If you want all the =
NamingContexts=20
within the name service to publish<BR>> > both addresses, look =
into the=20
endPointNoPublish option.<BR>> ><BR>> > In omniORB 3.0, =
there's no=20
option but to make the applications aware<BR>> > of the situation =
and have=20
them retry if they get COMM_FAILUREs.<BR>> ><BR>> > =
Cheers,<BR>>=20
><BR>> > Duncan.<BR>> ><BR>> > --<BR>> =
> --=20
Duncan Grisby --<BR>> =
> -- <A=20
href=3D"mailto:duncan@grisby.org">duncan@grisby.org</A> =
=20
--<BR>> > -- <A=20
href=3D"http://www.grisby.org">http://www.grisby.org</A> --<BR>> > =
_______________________________________________<BR>> > =
omniORB-list=20
mailing list<BR>> > <A=20
href=3D"mailto:omniORB-list@realvnc.com">omniORB-list@realvnc.com</A><BR>=
> >=20
<A=20
href=3D"http://www.realvnc.com/mailman/listinfo/omniorb-list">http://www.=
realvnc.com/mailman/listinfo/omniorb-list</A><BR></BODY></HTML>
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