[Spread-users] How to determine if message sent to a group was delivered to a consumer

John Schultz jschultz at spreadconcepts.com
Wed Feb 2 10:34:51 EST 2011


Spread is an ephemeral messaging system.  The only people that can receive a message are those that are present in the group (in the same partition) when the message is delivered.  Messages are not stored or queued for recipients who come to the group later or are in a different partition.

The only way to know whether or not a message was processed by a receiver is through some form of explicit ACK sent by that receiver.  Spread can give you a weaker guarantee using SAFE delivery.  In particular, if a receiver gets a SAFE message prior to a transitional signal in a membership, then it can know that that message will be delivered to all current members of the membership, unless they crash.

Cheers!

-----
John Lane Schultz
Spread Concepts LLC
Phn: 301 830 8100
Cell: 443 838 2200

On Feb 1, 2011, at 11:13 PM, Bernardinis, Mark wrote:

Hi All,
 
Background
 
I am investigating the uses of Spread for a project I am working on and have been successfully able to deliver messages  from the producer to the spread messaging system and retrieve them.
 
Objective
To publish a message to the spread system and find out if any subscribers received it (i.e. it is important that the message is processed).
 
Attempted
If I publish a message and there are no subscribers to the group where it was published to, the message is dropped on the floor (or so I believe)… I have confirmed this behaviour by starting a separate instance of my test program and joining the group where the message was delivered to and seeing if any messages existed (there wasn’t any).
 
I believe this is probably an elementary question and would appreciate any help. My setup is defined as follows;
 
System Setup
Spread Toolkit 4.1
Spread win32 binary running with the following configuration;
 
DebugFlags = { PRINT EXIT }
EventLogFile = testlog.out
EventTimeStamp = "[%a %d %b %Y %H:%M:%S]"
DangerousMonitor = false
 
Spread_Segment 10.230.51.17:3333 {
  machineD1 10.230.51.17
}
 
Regards,
Mark
 
 
************** IMPORTANT MESSAGE *****************************       
This e-mail message is intended only for the addressee(s) and contains information which may be
confidential. 
If you are not the intended recipient please advise the sender by return email, do not use or
disclose the contents, and delete the message and any attachments from your system. Unless
specifically indicated, this email does not constitute formal advice or commitment by the sender
or the Commonwealth Bank of Australia (ABN 48 123 123 124) or its subsidiaries. 
We can be contacted through our web site: 
commbank.com.au
. 
If you no longer wish to receive commercial electronic messages from us, please reply to this
e-mail by typing Unsubscribe in the subject line. 
**************************************************************



_______________________________________________
Spread-users mailing list
Spread-users at lists.spread.org
http://lists.spread.org/mailman/listinfo/spread-users

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 3805 bytes
Desc: not available
Url : http://lists.spread.org/pipermail/spread-users/attachments/20110202/46484066/attachment.bin 


More information about the Spread-users mailing list