real-time merge w/ multiple subscribers and a publisher

[Shon]

Hi,

In my app I want 2 subscribers and a publisher and I want all 3 DBs to
be synchronized in real-time.

The User Guide says: "Daffodil Replicator does not support
simultaneous synchronization between multiple Subscribers and a
Publisher."

Okay, before we get to that, I want to first understand how real-time
synchronization is handled with just 1 Subscriber and Publisher. So
say I add a schedule that specifies real-time synchronization. Now if
synchronize() is called only by the Subscriber, how can the scheduler
(which is running on the Subscriber) know to call synchronize() after
a commit is done on the Publisher end?

I presume the Publisher sends a message to the scheduler on the
Subscriber telling it to do one?

Shon

[Nitin Goyal]

Dear Shon

Replicator is actually a third entity which controls both publisher and subscriber. So this is done by replicator and not by code residing on subscriber/publisher.

Thanks
Nitin Goyal

[Shon]

Thank you for your answer.

"Replicator" is a term I see on the website but not in the
documentation that comes in the download. Same with "Replication
DataSource". I see Publication Server and Subscription Server only in
documentation downloaded with the product. Please what are the status
and meanings of these terms as they relate to my question.

Shon

[Shon]

OK so while I wait for an answer to my previous let's go back to my
initial question.

I want 2 subscribers and a publisher and I want all 3 DBs to be

synchronized in real-time. The documentation says this can not be
done. What are the technical issues that prevent this? Is there a work-
around? A solution that comes close to this, perhaps one that is not
"simultaneous"?

Shon

[Vinod Pahuja]

See this for further clearance

http://enterprise.replicator.daffodilsw.com/creating_subscription.html

--
Vinod Pahuja (विनोद पाहुजा)
+91 9896789651
Sr. Software Engineer
Daffodil Software Ltd.

[Shon]

Thank you for your answer.

I was asking about the status and meanings of "Replicator",
"Replication DataSource" and "Publication Server", "Subscription
Server" as they relate to my question in the first message. The link
about creating subscriptions does not mention these terms. So it is
still not clear to me.
Shon

On Sep 12, 10:29 pm, "Vinod Pahuja" <vinod.pah...@daffodildb.com>
wrote:

> See this for further clearance
>
> http://enterprise.replicator.daffodilsw.com/creating_subscription.html
>
>

[Nitin Goyal]

Hi Shon

Replicator - a software piece which acts as the controller of two types of data sources which are:

• JDBC Data Dource - used when you have Replicator installed in LAN with your database.
• RDS or Replicatio Data Source - This is a piece of software which helps you connect between a database and Replicator over WAN.

For e.g. there can be multiple scenarios
1.
                   LAN                            LAN
JDBC DS --------------- Replicator-------------------------- JDBC DS

2.
                   LAN                            WAN                       LAN
JDBC DS --------------- Replicator-------------------------- RDS -------------- JDBC

3.
                  LAN               WAN                            WAN                       LAN
JDBC DS ------------- RDS --------------- Replicator-------------------------- RDS -------------- JDBC


In the last scenario one can have RDS and JDBC on same system as well instead of in LAN. Also Replicator can be on a same system as of JDBC instead of on LAN in first and second scenario.

"Publication Server" and "Subscription Server" are terms used for Source Data Source and Target Data Source respectively. You just need to specify which one is "winner" to handle conflicts, if any occurs at sync time.

Hope this clears all queries.

Thanks
Nitin Goyal

[Nitin Goyal]

Hi Shon

Regarding your query

I want 2 subscribers and a publisher and I want all 3 DBs to be synchronized in real-time. The documentation says this can not be done. What are the technical issues that prevent this? Is there a work-around? A solution that comes close to this, perhaps one that is not "simultaneous"?

This can be done simultaneously using one to many job however there are some known issues in this. We are working on those issues and we will be providing a new version for it very soon. For time being we recommend you to use one to one job.

Thanks
Nitin Goyal