How to auto generate a snapshot for an existing subscriber

External Since: Jan 31, 2008 Posts: 10

Is it possible to set a merge publication to automatically generate a
snapshot for an existing subscriber if the subscription has expired
and the snapshot has become obsolete?

I have the retention period set to 14 days but it is highly likely
that a user may exceed this time, say if they are on vacation and
return to work. At the moment I am getting the error on the client
that the snapshot for the publication has become obsolete. I can
regenerate the snapshot on the server and then the client will
synchronise but this does not seem to be a satisfactory solution.

In Management Studio there is an option "Automatically define a
partition and generate a snapshot if needed when a new subscriber
tries to synchronise" but this just seems to refer to new subscribers
only. I presume in T-SQL the argument
"@allow_subscriber_initiated_snapshot" in sp_addmergepublication is
the same but the definition is not as precise and does not refer to
just new subscribers. In any case it is set to true and does not seem
to work for existing subscribers.

This may have been caused by the fact that I set the subscription for
reinitialisation at one point but I would still want to have this
possibility and the control at the client.

Am I missing a basic principle of replication here? To me it would
seem to be an important feature for the client to be able to
automatically trigger the regeneration of a new snapshot if necessary
without having to rely on intervention on the server.

Any help greatly appreciated.

External Since: Jan 16, 2008 Posts: 143

If a subscriber's retention period has expired and they have not
sync'd within the retention period, they will use the latest generated
snapshot. By default a merge snapshot is generated every 14 days which
is the default retention period.

The @allow_subscriber_initiated_snapshot option is only for dynamic
snapshots for filtered publications.

So you are missing nothing, its just the merge replication is
designed to create a single snapshot which all new subscribers will
use until there is a reinitialization or until they have not sync'd
within the retention period. In both of these later two cases they
will use the new snapshot.

New subscribers will use the snapshot that is generated and waiting
for them.

HTH

On Jan 31, 4:26 pm, JDS wrote:
> Is it possible to set a merge publication to automatically generate a
> snapshot for an existing subscriber if the subscription has expired
> and the snapshot has become obsolete?
>
> I have the retention period set to 14 days but it is highly likely
> that a user may exceed this time, say if they are on vacation and
> return to work. At the moment I am getting the error on the client
> that the snapshot for the publication has become obsolete. I can
> regenerate the snapshot on the server and then the client will
> synchronise but this does not seem to be a satisfactory solution.
>
> In Management Studio there is an option "Automatically define a
> partition and generate a snapshot if needed when a new subscriber
> tries to synchronise" but this just seems to refer to new subscribers
> only. I presume in T-SQL the argument
> "@allow_subscriber_initiated_snapshot" in sp_addmergepublication is
> the same but the definition is not as precise and does not refer to
> just new subscribers. In any case it is set to true and does not seem
> to work for existing subscribers.
>
> This may have been caused by the fact that I set the subscription for
> reinitialisation at one point but I would still want to have this
> possibility and the control at the client.
>
> Am I missing a basic principle of replication here? To me it would
> seem to be an important feature for the client to be able to
> automatically trigger the regeneration of a new snapshot if necessary
> without having to rely on intervention on the server.
>
> Any help greatly appreciated.