Geo Scada Redundancy - Main and Backup Centre

jouharn · ‎2024-02-14

Hi,

is there a solution in Geo Scada to have 2 sets of Main and Standby server redundancy in 2 locations. To be more specific we need a solution where we have 2 operation centers located in different locations. We can call it as Main and Backup centers. Each location shall have redundant pair of servers. Backup center shall be in listening mode (Only View mode) during normal operation and Main center shall be in control mode. If the servers in Main center (Main and standby) fails backup center shall come online. Both the Main and Backup center require hot standby servers, So a total of 4 servers in redundant configuration.

AdamWoodlandToo · ‎2024-02-14

No, what's you're asking for is quad-standby whereas Geo SCADA currently only supports up to triple-standby. You could in theory crowbar a fourth server in using performance servers (with triple-standby you can attach up to three performance servers) but it would require server restarts so understandably isn't very popular.

With current technologies customers seem to have implement this sort of functionality using the high availability functions of tools like Hyper-V and VMware, and fast backend backup solutions. E.g. have a stretched layer-2 network between the sites and you can usually bring the servers up on either side as necessary when there is a failure. For example having two servers at primary location, one at backup, if primary location fails review the failure scenario and you have the option to bring up one or two of the now "unavailable" servers at the backup location restoring the system back to your minimum required state.

It is much more expensive at the platform layer and I've yet to actually be involved myself in this sort of solution so I can't really say how easy it is, but I have seen some customers with this sort of setup and it seems to work for them. If your OT team aren't currently set up for this sort of failover then it might not be attractive but if your IT side already do this for their apps then it might not be such a big jump for the OT side, although the differences in how SCADA apps work in real-time may still cause some problems. It also comes down to your acceptable duration of running in a single-server mode, recovery might be "seamless" however may take time. It will be a case of thorough testing too!

It is really a case of moving the redundancy down the stack from the application to the platform, and in theory could mean dual-standby could also work for you. Moving to hosting in the cloud might also be something that is a solution that might help you here.

If you do want quad-standby you should raise the request with Schneider Electric formally, I know it has been discussed before in the past and the more customers who request it the more likely it might be added to the product.

See Answer In Context

AdamWoodlandToo · ‎2024-02-14

No, what's you're asking for is quad-standby whereas Geo SCADA currently only supports up to triple-standby. You could in theory crowbar a fourth server in using performance servers (with triple-standby you can attach up to three performance servers) but it would require server restarts so understandably isn't very popular.

With current technologies customers seem to have implement this sort of functionality using the high availability functions of tools like Hyper-V and VMware, and fast backend backup solutions. E.g. have a stretched layer-2 network between the sites and you can usually bring the servers up on either side as necessary when there is a failure. For example having two servers at primary location, one at backup, if primary location fails review the failure scenario and you have the option to bring up one or two of the now "unavailable" servers at the backup location restoring the system back to your minimum required state.

It is much more expensive at the platform layer and I've yet to actually be involved myself in this sort of solution so I can't really say how easy it is, but I have seen some customers with this sort of setup and it seems to work for them. If your OT team aren't currently set up for this sort of failover then it might not be attractive but if your IT side already do this for their apps then it might not be such a big jump for the OT side, although the differences in how SCADA apps work in real-time may still cause some problems. It also comes down to your acceptable duration of running in a single-server mode, recovery might be "seamless" however may take time. It will be a case of thorough testing too!

It is really a case of moving the redundancy down the stack from the application to the platform, and in theory could mean dual-standby could also work for you. Moving to hosting in the cloud might also be something that is a solution that might help you here.

If you do want quad-standby you should raise the request with Schneider Electric formally, I know it has been discussed before in the past and the more customers who request it the more likely it might be added to the product.