Split mode in distributed system

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claire.lam
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Joined: Wed Jan 06, 2016 10:29 am

Split mode in distributed system

Post by claire.lam »

We have a distributed system composed of 4 redundant systems (2 redundant servers on each system).

The question is : can split mode be activated simultaneously on the 4 systems ? Or should we have split mode activated on only one system and the other systems have to remain in redundancy mode ?

Thank you

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leoknipp
Posts: 2567
Joined: Tue Aug 24, 2010 7:28 pm

Re: Split mode in distributed system

Post by leoknipp »

There is no function available to switch all redundant systems in split mode in one command.
Why do you want to use the split mode?
What is done after switching the systems into the split mode?

Best Regards
Leopold Knipp
Senior Support Specialist

claire.lam
Posts: 3
Joined: Wed Jan 06, 2016 10:29 am

Re: Split mode in distributed system

Post by claire.lam »

It is not necessary to swicth all redundant systems in split mode in one single command.

But can all systems be in split mode at the same time ? For example, if system 1 is already in split mode, can I switch system 2 in split mode and keep system 1 in split mode too ?

We want to use split mode to install new versions in our application. The advantage of split mode is that the application continues to work during version upgrade. And if any error occurs during version upgrade, we can cancel the operation and keep the old version when we switch back to redundancy mode.

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leoknipp
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Joined: Tue Aug 24, 2010 7:28 pm

Re: Split mode in distributed system

Post by leoknipp »

It is possible to use the split mode in several redundant systems at the same time.
If there are more systems in split mode you have to ensure that the "active" dist manager is set correctly in all systems.

When talking about a "version upgrade", is it an upgrade of the WinCC OA version?

Best Regards
Leopold Knipp
Senior Support Specialist

claire.lam
Posts: 3
Joined: Wed Jan 06, 2016 10:29 am

Re: Split mode in distributed system

Post by claire.lam »

No, the WinCC OA software (version V3.17) is not modified.
"Version upgrade" means update of PARA and panels in our WinCC OA project.
Indeed, the data and the panels of our application are configurable.
What can be updated in the PARA :
- Add datapoints (in an existing datapoint type)
- Delete datapoints
- Modify configs : _original, _common, _pv_range, _general, _alert_hdl, _address, _smooth, _archive
What can be updated in the panels :
- Add / delete / move a symbol in an existing panel

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leoknipp
Posts: 2567
Joined: Tue Aug 24, 2010 7:28 pm

Re: Split mode in distributed system

Post by leoknipp »

The split mode can be used to test changes in the database.
If you modify panels/scripts you have to do the rollback on your own if the split mode is left and you want to use the old files.

Best Regards
Leopold Knipp
Senior Support Specialist

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6 posts • Page 1 of 1