Alternative to Redundancy

Ignition
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1

We are trying to setup 2 servers with Independent Ignitions and start the Ignition service on backup server only when master server is down. The reason for not using Ignition redundancy is that both servers will have different postgres DBs and Ignition needs to connect to DB on its own machine. My question is how to redirect Clients to the backup ignition when Master server is not reachable?

2

configuration>redundancy

then uncheck autodetect http address and put the 2 servers in the http addresses list. I am not sure that this will work with 2 separate projects, but it is worth a shot I guess.

3

If databases are your only problem, you could consider adding a fallback DB connection.

See https://docs.inductiveautomation.com/display/DOC/Database+Considerations

Then you can use regular redundancy and when one server fails with its DB, the clients will switch to the redundant server, and the redundant server should use either the DB on the primary server (if that’s still up and f.e. only Ignition crashed), or fall back to its own redundant DB.

4

Thanks. This sounds good. I will definitely give it a try.

5

What about using redundancy and pointing the DB to localhost?

1 Like
6

Can we use different configurations in backup ignition? I could not change the backup project. It uses the same project as master.It shows the Error " Cannot make configuration changes to a non-master node". If there is a way to change backup projects, I would like to give it a shot.

7

@diat150 I was successful in setting up 2 servers in the http address list and with separate DB connections. If I shutdown gateway on my primary server, clients move to the backup server. However when primary server is restarted, the clients won’t move back to primary as they would if redundancy was set master/backup. I am now trying to write some script to have only one gateway running at a time. Any ideas will be appreciated.

8

You also have to watch out with that approach when you use tag triggers or gateway scripts to update other tags. With the regular master/backup config, the connections to the PLC are disabled, so the backup can’t write to the PLC. If you have two independent gateways, the one you use as backup can write to the PLC.