Disaster recovery strategies in GCP - Step-by-Step Execution

Process Flow - Disaster recovery strategies

Disaster Occurs

↓

Detect Disaster

↓

Activate Recovery Plan

↓

Switch to Backup Site

↓

Restore Data & Services

↓

Verify System Health

↓

Resume Normal Operations

This flow shows the steps taken when a disaster happens, from detection to recovery and resuming normal service.

Execution Sample

GCP

1. Detect disaster event
2. Activate recovery plan
3. Switch traffic to backup
4. Restore data from backup
5. Verify system health
6. Resume operations

This sequence outlines the key actions in a disaster recovery process on GCP.

Process Table

Step	Action	Condition/Check	Result/Next Step
1	Detect disaster event	Disaster detected?	Yes -> Activate recovery plan
2	Activate recovery plan	Plan available?	Yes -> Switch traffic to backup
3	Switch traffic to backup	Backup site ready?	Yes -> Restore data from backup
4	Restore data from backup	Data restored?	Yes -> Verify system health
5	Verify system health	Systems healthy?	Yes -> Resume operations
6	Resume operations	Operations resumed	Disaster recovery complete
7	If any check fails	No	Repeat previous step or alert team

💡 Disaster recovery completes when operations resume successfully or manual intervention occurs if checks fail.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	Final
DisasterDetected	False	True	True	True	True	True	True
RecoveryPlanActivated	False	False	True	True	True	True	True
TrafficSwitched	False	False	False	True	True	True	True
DataRestored	False	False	False	False	True	True	True
SystemHealthy	False	False	False	False	False	True	True
OperationsResumed	False	False	False	False	False	False	True

Key Moments - 3 Insights

Why do we check if the backup site is ready before switching traffic?

Because switching traffic to a backup site that is not ready can cause service outages. See execution_table step 3 where the condition 'Backup site ready?' must be Yes to proceed.

What happens if data restoration fails?

The process does not move forward. According to execution_table step 4, if 'Data restored?' is No, the system repeats the step or alerts the team to fix the issue.

Why verify system health after restoring data?

Verifying system health ensures all services work correctly before resuming operations. This is shown in execution_table step 5 where 'Systems healthy?' must be Yes to continue.

Visual Quiz - 3 Questions

Look at the execution_table, at which step is traffic switched to the backup site?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Check the 'Action' column for 'Switch traffic to backup' in the execution_table.

According to variable_tracker, what is the value of DataRestored after Step 4?

A True

B False

C Undefined

D Null

💡 Hint

Look at the 'DataRestored' row under 'After Step 4' in variable_tracker.

If the system health check fails at Step 5, what does the execution_table say happens next?

A Resume operations anyway

B Repeat previous step or alert team

C Skip to Step 6

D Ignore and continue

💡 Hint

Refer to the last row in execution_table about what happens if any check fails.

Concept Snapshot

Disaster recovery strategies in GCP:
- Detect disaster quickly
- Activate recovery plan
- Switch traffic to backup site only if ready
- Restore data from backups
- Verify system health before resuming
- Repeat or alert if any step fails
This ensures minimal downtime and data loss.

Full Transcript

Disaster recovery strategies involve detecting a disaster, activating a recovery plan, switching traffic to a backup site, restoring data, verifying system health, and resuming normal operations. Each step requires checks to ensure readiness before moving forward. If any check fails, the process repeats or alerts the team to prevent further issues. This approach helps keep services running with minimal interruption during disasters.

Practice

1. What is the main goal of a disaster recovery strategy in cloud infrastructure?

easy

A. To improve user interface design

B. To keep services running during unexpected problems

C. To increase the speed of data processing

D. To reduce the cost of cloud services

Solution

1. Step 1: Understand disaster recovery purpose

   Disaster recovery aims to keep systems available and data safe during failures or disasters.

2. Step 2: Identify the main goal

   The main goal is to maintain service uptime and data integrity despite problems.

3. Final Answer:

   To keep services running during unexpected problems -> Option B

4. Quick Check:

   Disaster recovery = keep services safe [OK]

Hint: Disaster recovery means service stays up during trouble [OK]

Common Mistakes:

• Confusing disaster recovery with cost saving
• Thinking it improves speed or UI
• Ignoring service availability

2. Which GCP service is commonly used to store backups for disaster recovery?

easy

A. Cloud Pub/Sub

B. Google Compute Engine

C. Google Kubernetes Engine

D. Google Cloud Storage

Solution

1. Step 1: Identify backup storage service

   Backups need durable, scalable storage. Google Cloud Storage is designed for this.

2. Step 2: Exclude compute and messaging services

   Compute Engine and Kubernetes Engine run workloads, Pub/Sub handles messaging, not backups.

3. Final Answer:

   Google Cloud Storage -> Option D

4. Quick Check:

   Backup storage = Cloud Storage [OK]

Hint: Backups go to Cloud Storage, not compute or messaging [OK]

Common Mistakes:

• Choosing compute services for backup storage
• Confusing messaging service with storage
• Not knowing Cloud Storage purpose

3. Consider this GCP setup code snippet for disaster recovery:

resource "google_compute_instance" "primary" {
  name         = "primary-instance"
  zone         = "us-central1-a"
  machine_type = "e2-medium"
  boot_disk {
    initialize_params {
      image = "debian-cloud/debian-11"
    }
  }
}

resource "google_compute_instance" "backup" {
  name         = "backup-instance"
  zone         = "us-central1-b"
  machine_type = "e2-medium"
  boot_disk {
    initialize_params {
      image = "debian-cloud/debian-11"
    }
  }
}

What is the main benefit of this configuration for disaster recovery?

medium

A. It creates two instances in different zones to improve availability

B. It reduces the cost by using smaller machines

C. It backs up data automatically to Cloud Storage

D. It enables faster network speed between instances

Solution

1. Step 1: Analyze instance zones

   The two instances are in different zones (us-central1-a and us-central1-b), which protects against zone failure.

2. Step 2: Identify disaster recovery benefit

   Having instances in separate zones improves availability and fault tolerance during disasters.

3. Final Answer:

   It creates two instances in different zones to improve availability -> Option A

4. Quick Check:

   Multi-zone instances = better availability [OK]

Hint: Different zones mean better uptime during failures [OK]

Common Mistakes:

• Assuming cost reduction is main goal
• Thinking data backup happens automatically
• Confusing network speed with disaster recovery

4. You have a disaster recovery plan that uses snapshots for backups. After a disaster, the recovery fails because snapshots are missing. What is the most likely error?

medium

A. Snapshots were stored in the same zone as the primary data

B. Snapshots were not scheduled regularly

C. Snapshots were encrypted with the wrong key

D. Snapshots were created from the wrong disk

Solution

1. Step 1: Understand snapshot storage risk

   If snapshots are stored only in the same zone, a zone failure can destroy both primary data and backups.

2. Step 2: Identify cause of missing snapshots

   Storing snapshots in the same zone risks losing them during a disaster affecting that zone.

3. Final Answer:

   Snapshots were stored in the same zone as the primary data -> Option A

4. Quick Check:

   Backups must be in different zones [OK]

Hint: Backups in same zone vanish with disaster [OK]

Common Mistakes:

• Ignoring backup location importance
• Assuming encryption or disk choice caused failure
• Not scheduling snapshots regularly

5. You want to design a disaster recovery plan for a critical GCP application that must recover within minutes after a regional outage. Which combination of strategies is best?

hard

A. Use multi-zone deployment with weekly snapshots and manual recovery

B. Use single-zone deployment with daily manual backups to Cloud Storage

C. Use multi-region deployment with automated failover and continuous data replication

D. Use single-region deployment with monthly backups and no failover

Solution

1. Step 1: Identify recovery time objective (RTO)

   Recovery within minutes requires fast failover and minimal data loss.

2. Step 2: Evaluate strategies for fast recovery

   Multi-region deployment with automated failover and continuous replication ensures quick switch and up-to-date data.

3. Step 3: Compare with other options

   Single-zone or single-region with manual backups are slower and risk data loss; weekly or monthly backups are too infrequent.

4. Final Answer:

   Use multi-region deployment with automated failover and continuous data replication -> Option C

5. Quick Check:

   Fast recovery needs multi-region + automation [OK]

Hint: Fast recovery needs multi-region and automation [OK]

Common Mistakes:

• Choosing single-zone or single-region for critical apps
• Relying on manual backups for quick recovery
• Ignoring continuous data replication