Hot standby and warm standby in SCADA systems - Mini Project: Build & Apply

Hot Standby and Warm Standby Setup in SCADA Systems

📖 Scenario: You are working with a SCADA (Supervisory Control and Data Acquisition) system that controls a water treatment plant. To ensure the system is always available, you need to set up backup servers. These backups can be in two modes: hot standby and warm standby.Hot standby means the backup server is running and ready to take over immediately if the main server fails. Warm standby means the backup server is running but not fully active; it needs some time to start handling tasks if the main server fails.

🎯 Goal: You will create a simple data structure to represent the main server and its backup servers with their standby modes. Then, you will configure a threshold for switching to backup, write logic to check which backup server should take over, and finally display the active server.

📋 What You'll Learn

Create a dictionary named servers with keys main, backup1, and backup2.

Set backup1 to hot_standby and backup2 to warm_standby.

Create a variable failure_threshold set to 5 representing failure count to trigger backup.

Write logic to check if failure count exceeds threshold and select the correct backup server based on standby mode.

Print the name of the active server after the check.

💡 Why This Matters

🌍 Real World

SCADA systems control critical infrastructure like water plants and power grids. Having backup servers ensures the system keeps running even if one server fails.

💼 Career

Understanding hot and warm standby setups is important for roles in system administration, network operations, and DevOps to maintain high availability.

1

Create the servers dictionary

Create a dictionary called servers with these exact entries: 'main': 'active', 'backup1': 'hot_standby', and 'backup2': 'warm_standby'.

SCADA systems

# Create the servers dictionary with main and backup servers
# Your code here

Need a hint?

Use curly braces to create a dictionary with keys and values exactly as shown.

2

Set failure threshold

Create a variable called failure_threshold and set it to 5.

SCADA systems

servers = {'main': 'active', 'backup1': 'hot_standby', 'backup2': 'warm_standby'}
# Set failure threshold to 5
# Your code here

Need a hint?

Just assign the number 5 to the variable failure_threshold.

3

Check failure and select backup

Create a variable called failure_count and set it to 6. Then write an if statement that checks if failure_count is greater than failure_threshold. Inside the if, set a variable active_server to 'backup1' if servers['backup1'] is 'hot_standby', else set active_server to 'backup2'. If the if condition is false, set active_server to 'main'.

SCADA systems

servers = {'main': 'active', 'backup1': 'hot_standby', 'backup2': 'warm_standby'}
failure_threshold = 5
# Check failure count and select active server
# Your code here

Need a hint?

Use nested if statements to check conditions and assign active_server.

4

Display the active server

Write a print statement to display the text "Active server: " followed by the value of the variable active_server.

SCADA systems

servers = {'main': 'active', 'backup1': 'hot_standby', 'backup2': 'warm_standby'}
failure_threshold = 5
failure_count = 6
if failure_count > failure_threshold:
    if servers['backup1'] == 'hot_standby':
        active_server = 'backup1'
    else:
        active_server = 'backup2'
else:
    active_server = 'main'
# Print the active server
# Your code here

Need a hint?

Use print("Active server: " + active_server) to show the result.