Synchronizing of second combined ASCS to the system
What is the right way to synchronize the second combined ASCS to the first one (system)?
The system is 800xA ver. 6.0.3. Initially both ASCS1 and ASCS2 have been installed from SCC and synchronized, and the new system created.
Then one of the servers has been disconnected from the system and the engineering of the system is done only with one of the servers.
There are no any additional services, options or updates installed to 800xA during the engineering.
Now we want to connect both servers and synchronize them as redundant pair.
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ASCS1 should now slave to ASCS2 and synchronize with it (the only server having an Aspect Directory and other services in Service State).
If possible, try this in some VMware Player/Workstation setup (who hasn't a virtualization solution in his laptop nowadays?).
The individual order of service providers in a service group is crucial during synchronization, if AS1 meet AS2 after an outage and their content differ, the one "highest" in provider order will win. The old AspDir folder will be renamed to AspDir.1 and can serve as a way out (stop, rename, start), but there are other databases like FSD that acts differently. A Control Builder M project may become damaged if the .hwd files inserted/modified by the "loosing" aspect server are wiped out.
I assume that ASCS1 and ASCS2 were initially configured as a pair of redundant servers.
I assume that you by "disconnect" mean a physically disconnect on the level of such as a network disconnect.
As I understand your situation, both ASCS were synchronized before disconnecting the one of the ASCS from the other, right?
In case this is correct, I will assume that synchronization will happen automatically when you connect both ASCS to each other again.
Nothing needs to be done manually to initiate synchronization.
If this is not the case, with only 2 servers (1 out of 2 redundant) it can happen that you will synchronize back to the old state and loose all changes.
Thank you all for your kind advices. Both servers are now synchronized.
I found a valuable ideas in all your posts ! Mostly about master/slave roles and the behaviour of both servers.
Next time we will may be try with renaming of OperateITData folder.
What we did:
- in service structure, we moved the services for ASCS2 on top of their service groups (because we needed ASCS2 as Master)
- start Control Builder in OnLine mode to the controllers
- connected ASCS1 to the networks and start-up the server
- wait for synchronizing of the servers
- manually adjust some services to run properly on ASCS1 and reboot of ACSC1 in single mode
- stop and start Server on ASCS1 trough Configuration Wizard. That fixed missing data from OPC Server in ASCS1
- reconnect ASCS2