Redundant server configuration in SCADA systems - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of redundant server configuration in SCADA systems?

To ensure continuous operation and availability by having backup servers ready to take over if the primary server fails.

beginner

Name two common types of redundancy used in server configurations.

Active-Active redundancy where all servers run simultaneously, and Active-Passive redundancy where a backup server is idle until needed.

intermediate

How does failover work in a redundant server setup?

Failover automatically switches operations from a failed primary server to a backup server to minimize downtime.

intermediate

Why is testing failover important in redundant server configurations?

To verify that backup servers take over correctly and the system remains operational without data loss or delays.

intermediate

What role does synchronization play in redundant server configurations?

It keeps data and system states consistent between primary and backup servers to ensure seamless switching.

What happens in an Active-Passive redundant server setup?

A Backup server is idle until primary fails.

B Primary server is always offline.

C Servers operate independently without failover.

D Both servers run simultaneously sharing the load.

In Active-Passive setups, the backup server waits idle and only activates if the primary server fails.

Which is a key benefit of redundant server configuration?

A Less maintenance needed.

B Reduced hardware costs.

C Slower response times.

D Improved system availability.

Redundancy improves availability by providing backup servers to take over if one fails.

What is failover in redundant server systems?

A Switching to backup server automatically.

B Manual restart of servers.

C Shutting down all servers.

D Updating server software.

Failover means automatically switching operations to a backup server when the primary fails.

Why must data be synchronized between redundant servers?

A To save storage space.

B To ensure backup server has current data.

C To slow down the system.

D To avoid using backups.

Synchronization ensures the backup server has the latest data for seamless failover.

What is tested during failover testing?

A Backup server performance under load.

B Primary server shutdown speed.

C Automatic switch to backup server works correctly.

D Network speed between servers.

Failover testing checks that the system switches to the backup server without issues.

Explain how redundant server configuration improves reliability in SCADA systems.

Think about what happens when the main server stops working.

Describe the difference between Active-Active and Active-Passive redundancy.

Consider if backup servers are working all the time or only when needed.