Indirect Synchronization without Synchronizer on Server

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

rdemyan@hotmail.com - 22 Dec 2006 06:13 GMT

Here's the situation;

1) Not allowed to install Jet Synchronizer on server, but can install
it on remote PCs.
2) Can't add a desktop to the LAN to handle synchronization in lieu of
the server.
3) Assume 4 locations. The server that will be used by all locations
is at Location 1. Access to this server is quite fast for any user at
Location 1 as it is on a LAN network. The other locations probably
include a WAN in the network to access the server at Location 1.

So I'm wondering if the following is a possibility.

1) Locate the common dropbox for the synchronization messages from the
remotes on the server. Is it then possible to somehow send these
messages to the dropbox of each user so that they can synchronize with
these messages. This would avoid the need to have the Jet Synchronizer
on the server. The server would have the dropbox, but any messages
deposited in it would then somehow be forwarded (pushed or pulled) to
each user's machine and the synchronization done at each remote
machine.
2) It would still, however, be desirable to have a replica on the
server that could serve as a means for making new remote replicas as
needed. So how about having one of the users at Location 1, which has
the fast LAN including the server, create the replica for the server
and use direct synchronization with that copy to keep it uptodate.
Only a user on the server's LAN would do this (i.e Location 1); no
direct synchronization over WANs or dial-ups.

Can this work??

Reply to this Message

David W. Fenton - 22 Dec 2006 18:53 GMT

> Here's the situation;
>
[quoted text clipped - 14 lines]
> these messages to the dropbox of each user so that they can
> synchronize with these messages.

Each synchronizer needs a dropbox, rather than each replica. All
messages put into the dropbox are applied to all replicas managed by
a synchronizer (unless they're from a different replica set, of
course).

So, you don't need a different dropbox for each user, but for each
machine that has a synchronizer.

That's only relevant to users who are synching via indirect
replication. My understanding is that you have 3 sites, each with a
server. In that situation, I'd set up indirect replication on the
three servers and have them synch with each other indirect on a
schedule.

Now, of course, as you say, you can't install on the servers, but if
you had a workstation in each location acting as host for the
synchronizer, that would work, too. The actual replicas being
synched and the dropbox would be on the server, instead of on the
workstation hosting the synchronizer.

> This would avoid the need to have the Jet Synchronizer
> on the server. The server would have the dropbox, but any
> messages deposited in it would then somehow be forwarded (pushed
> or pulled) to each user's machine and the synchronization done at
> each remote machine.

No, it's precisely the opposite. The synchronizer places messages in
the remote machine's dropbox. The dropbox on the server would be
receiving messages from the remote machine, and the synchronizer on
the workstation would then apply the messages to the managed
replica(s) stored on the local server.

That is, the setup works, just not the way you describe it.

> 2) It would still, however, be desirable to have a replica on the
> server that could serve as a means for making new remote replicas
> as needed.

I'd never store my replicas for indirect synch anywhere else.

> So how about having one of the users at Location 1,
> which has the fast LAN including the server, create the replica
> for the server and use direct synchronization with that copy to
> keep it uptodate. Only a user on the server's LAN would do this
> (i.e Location 1); no direct synchronization over WANs or dial-ups.

I lost you on this last one.

You have three locations with local LAN users at each location.
Indirect synch should be between the replication hubs stored on the
server at each location. The synchronizer can run on any machine on
the LAN local to each server, and the dropboxes and replicas
involved can be stored on the server local to the machine running
the synchronizer.

Signature

David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

Reply to this Message

rdemyan@hotmail.com - 22 Dec 2006 19:18 GMT

Can a synchronizer on a remote machine grab a message from a dropbox on
a server; said server not having a synchronizer on it.

> > Here's the situation;
> >
[quoted text clipped - 73 lines]
> David W. Fenton http://www.dfenton.com/
> usenet at dfenton dot com http://www.dfenton.com/DFA/

Reply to this Message

David W. Fenton - 22 Dec 2006 23:34 GMT

> Can a synchronizer on a remote machine grab a message from a
> dropbox on a server; said server not having a synchronizer on it.

Every remote synchronizer has to running on a "server", i.e., a
machine that offers up shared folders, one of which is the dropbox.

Synchronizer A running on Workstation A has DropBox A.

Server B running on Server B has DropBox B.

When the two synchronizers perform an indirect synch, Workstation A
puts files in Dropbox B (on Server B), and Server B puts files in
Dropbox A (on Workstation A). Each synchronizer monitors its own
dropbox for new files and then reads them and does something in
response (it may be taking the files and applying them to its
managed replicas, or it may be dropping some files in the other
synchronizer's dropbox to tell the remote synchronizer something
that it needs to know).

If any files are lost in the transition, it doesn't matter, because
changes have not been made to the replicas, just to the contents of
the dropboxes. This is why Indirect replication is so safe and
efficient.

Signature

David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

Reply to this Message