Replication In 11.7

[ForEachInvoiceDelete]

Im trying to turn on the new "Inter-Agent Communication" or "Target Sync". It seems to have multiple names depending on what part of the documentation you find.

Cant for the life of me find anything about turning it on. Just that you need it and its amazing.

Anyone point me in the right direction?

- Jason

 

[Cringer]

There was a load of discussion about it in the ESAP group on Communities but it looks like that's all been deleted which is annoying. I would post up in Communities though. I believe George Potemkin has been using it and there's a couple of others as well. There's obviously the PSC folk around there too.

 

[Rob Fitzpatrick]

I stepped through the exercise in ESAP 3, I think it was. As I recall it wasn't so much a case of turning on a feature as the way you set up the repl.properties. I'll see if I still have the docs from that ESAP to fill you in further.

 

[ForEachInvoiceDelete]

Yeah that would be great. Cant find anything in the documentation still!

Ill probably set up a Progress communities login later tonight. My progress ID doesnt seem to be working either!

 

[Rob Fitzpatrick]

The NeRF manual throws a third term into the mix: Replication Sets. That's what they called it during the ESAP, but I think the new marketing name is Replication Target Synchronization.

I've gone through my ESAP docs and downloads and it looks like I no longer have the instructions from ESAP 3 that detail how to set up and test a replication set; sorry. I've looked at the 11.7 docs as well and the only reference I can find to this feature is the little blurb in the NeRF manual. There's a two-page marketing sheet on the web site that mentions it but it doesn't contain any real details.

 

[Rob Fitzpatrick]

OK, I've checked again.

It looks like Marketing and Documentation are not on speaking terms. The docs (apart from NeRF) call this feature Replication Sets. If you search the Replication User Guide for "Replication Set", you'll find lots of hits.

 

[ForEachInvoiceDelete]

OpenEdge 11.7 Documentation

I found this.

I still dont see how to create a replication set!/Target Synchronisation/Inter-Agent Communication

Am i being blind, stupid or a combination of both?

 

[Rob Fitzpatrick]

I see what you're saying. This feature isn't explained as well as it could be. It seems like there is some missing info on Replication Sets in chapter 4, about defining properties files. There are lots of references in the docs like "if you have defined a replication set..." but I can't find any clear instructions on how to do so.

Chapter 5, page 118 (of the PDF), Transition of a Replication Set has a hint, in this excerpt of a server properties file:

[transition]
replication-set=1                        <=====
transition-to-agents=agent1,agent2       <=====
database-role=reverse
restart-after-transition=1

The following pages give a bit more detail, explaining the individual properties. Search for the explanations of "replication-set" and "transition-to-agents".

 

[ForEachInvoiceDelete]

!! Brilliant. Thanks for finding that hidden nugget of information.

ill play around with setting these.

 

[DBA_learner]

Hello All,

Please help me about replication set. By checking below parameters, it seems like we could have multiple targets synced with one replication source.

     [transition]
           replication-set=1                        
           transition-to-agents=agent1,agent2

We have few replication servers running (one to one mapped) with Live servers and if Live goes down for some reason then we have to stop target database, stop replication as target and run it as source and after that we are able to run (read/update) the application with latest transaction of Live server.

Please let me know if Replication-set is a better option of accessing Target application.

Regards,

 

[Rob Fitzpatrick]

Please help me about replication set. By checking below parameters, it seems like we could have multiple targets synced with one replication source.

The new feature, Replication Sets, doesn't change the number of replication targets you can have. OpenEdge Replication and Replication Plus both let you have either one or two target databases updated by a source.

Prior to 11.7, a target database could transition to a source or to a normal (non-replicated) database. There are certain things you can automate, like enabling adding AI extents and after-imaging in the new source after transition. But the two targets have no knowledge of each other. After the failure of the original source and the transition, there is a period of time where you have a single point of failure until you set up the former target2 as the new replication target of the new source (which used to be target1).

The new feature in 11.7 is inter-agent communication, i.e. the agents of targets 1 and 2 are aware of and communicate with each other, when the three are configured as a replication set. When the source fails, target1 transitions to become the new source and target2 also transitions to become its new target, preserving failover capability.

 

[DBA_learner]

Thanks for this valuable information @Rob Fitzpatrick