NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/comp/sys/isis/207

Text File | 1992-07-25 | 1.8 KB | 38 lines

Newsgroups: comp.sys.isis
Path: sparky!uunet!zaphod.mps.ohio-state.edu!rpi!scott.skidmore.edu!psinntp!psinntp!ibism!kpt
From: [e-mail] (Kevin P. Tyson)
Subject: A question about network partition on process groups
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: IISA
Date: Thu, 23 Jul 1992 19:00:06 GMT
Lines: 27

I am very new to ISIS so please forgive me if this is a FAQ.  I am interested
in using ISIS to implement replicated resource managers.  My understanding is
that the Client-Server Group mechanism is the technique to use for this type
of processing and that the logging facility is the mechanism to use when new
replicas need to be added to the group.

My question concerns the effect of network partition on the server members of
the process group.  Suppose we have a server process group running on four
nodes on a single ethernet segment.  Each node has at least the Protos process
and the server process running.  Each server process is responding to all rpc
calls made to the group.  At some point the segment is split into two segments
of two nodes each.  I assume that the Protos processes on each node will
detect the missing nodes and on the segment which now lacks the primary server
will promote one of the two remaining server processes to the role of primary.
The result of this will be two server process groups, each of which will
continue to operate.

At some point the segments will have to be re-united.  What support is there
in ISIS for detecting the changes that may have gone to one but not both of
the server groups while the network was partitioned?  What support is there
for merging the two server groups into a single server group?

Thanks in advance,
--

Kevin P. Tyson        Phone:  [phone]    Fax:    [phone]
E-Mail: [e-mail]