ASG
IBM
Zystems
Cressida
Icon
Netflexity
 
  MQSeries.net
Search  Search       Tech Exchange      Education      Certifications      Library      Info Center      SupportPacs      LinkedIn  Search  Search                                                                   FAQ  FAQ   Usergroups  Usergroups
 
Register  ::  Log in Log in to check your private messages
 
RSS Feed - WebSphere MQ Support RSS Feed - Message Broker Support

MQSeries.net Forum Index » Clustering » Sequence messages across a cluster?

Post new topic  Reply to topic
 Sequence messages across a cluster? « View previous topic :: View next topic » 
Author Message
pavdaddy72
PostPosted: Wed Jan 07, 2015 6:41 am    Post subject: Sequence messages across a cluster? Reply with quote

Newbie

Joined: 07 May 2014
Posts: 6

How can I ensure that messages remain in sequence across a cluster? Does the sequence node accomplish this or is there further administration work that needs to be setup?

Long story short, we're trying to figure out if we can keep messages in sequence across a cluster of brokers. For example, if a flow was running on 2-4 brokers, can we use sequence nodes to mainatin order. Or is there a different way to accomplish this?

Obviously, any other ideas to meet the same requirement are useful too.

Unable to find any IBM links or docs that talk about maintaining sequence over clusters. Thanks,

Jason
Back to top
View user's profile Send private message
fjb_saper
PostPosted: Wed Jan 07, 2015 6:53 am    Post subject: Reply with quote

Grand High Poobah

Joined: 18 Nov 2003
Posts: 20696
Location: LI,NY

Well there is a kind of round about way.
You need to set the default bind on open property to GROUP.
Then you need to send all the messages that need sequencing in the same group... and to use a re-sequencing node on the broker...

Basically your cluster represents a bunch of threads to which you are going to dispatch work in a round robin manner. Nobody cares about the order and you have no control because you are processing the different threads in parallel...
Setting the default bind to group AND sending the messages as a group allows you to send all the messages in the group to the same "thread". But there is no guarantee that they will arrive in order on the thread...

Hence the potential need to re-sequence at arrival point.
And you need to give a lot of thought about how you are going to handle out of sequence messages...., and what represents a new sequence rather than the continuation of an existing one?

How do you handle a sequence that skips a number between 2 quiet intervals???

Have fun
_________________
MQ & Broker admin
Back to top
View user's profile Send private message Send e-mail
mqjeff
PostPosted: Wed Jan 07, 2015 8:46 am    Post subject: Reply with quote

Grand Master

Joined: 25 Jun 2008
Posts: 17447

You would use a single Sequence node to assign a sequence to each message.

You would then fan the messages across the cluster for processing.

You would then use a single REsequence node to emit the messages in the proper sequence.

This is essentially a fan-out/fan-in process.

If you want to ensure that Message 2 is always processed after message 1 and before message 3, you can't process them on different servers.

Unless you want to do something dumb like use Global Cache to implement a lock.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic  Reply to topic Page 1 of 1

MQSeries.net Forum Index » Clustering » Sequence messages across a cluster?
Jump to:  



You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Protected by Anti-Spam ACP
 
 


Theme by Dustin Baccetti
Powered by phpBB © 2001, 2002 phpBB Group

Copyright © MQSeries.net. All rights reserved.