Cost Optimization Mastery: Winning the PCA Exam "Efficiency" Questions
In the GCP PCA exam, "cost-effective" is a keyword that changes everything. An answer might be technically correct, but if there's a cheaper way to do it that still meets requirements, the cheaper one is the only right answer. Let's learn to spot the savings.
Compute: Don't Pay More Than You Must
Compute is usually the biggest line item. To optimize it for the exam:
- Committed Use Discounts (CUDs): Use these for steady-state workloads (1 or 3 year predictable load).
- Preemptible / Spot VMs: Use these for batch processing or fault-tolerant workloads where a 60-90% saving is worth the risk of interruption.
- Rightsizing: Pay attention to Recommender API suggestions to shrink over-provisioned VMs.
Storage: Lifecycle is Everything
Cloud Storage is cheap, but it adds up. The PCA exam tests your knowledge of Storage Classes:
- Standard: Active data.
- Nearline: Backup (accessed < once / 30 days).
- Coldline: Disaster recovery (accessed < once / 90 days).
- Archive: Compliance / Long-term keep (accessed < once / year).
Pro Tip: Always suggest Lifecycle Policies to automate the move from Standard to Archive.
BigQuery: Slots and Flat-rate Pricing
BigQuery is serverless, but it can get expensive with "on-demand" pricing if you're running massive queries.
- On-demand: Best for small, unpredictable queries.
- Capacity-based (Flat-rate/Slots): Best for large enterprises with predictable, heavy analytics needs. It caps your cost.
- Partitioning & Clustering: Not just for performance! Reducing the data scanned reduces the cost of the query.
Frequently Asked Questions (FAQ)
What is the benefit of Sustained Use Discounts (SUDs)?
SUDs are automatic discounts you receive for running specific Compute Engine instances for a significant portion of the billing month. No commitment is required.
How can I visualize my GCP costs?
By using Billing Reports, Cost Table, and exporting your billing data to BigQuery for visualization in Looker Studio.
What are Budgets and Alerts?
Budgets allow you to set a target spend for your projects, and Alerts notify billing administrators when certain thresholds (e.g., 50%, 90%, 100%) are reached.
How to optimize costs for TerramEarth?
For TerramEarth's massive IoT data, use lifecycle policies to move raw data from Standard to Archive storage classes — check our TerramEarth deep-dive.
Is Spanner or Bigtable cheaper?
It depends on the workload. Use our database decision tree to pick the right tool for the job to avoid over-provisioning costs.
Exam Trick: If a scenario mentions a "tight budget" and "long-term data retention," your answer should include Cloud Storage Archive class and Object Lifecycle Management.
Monitoring and Billing Tools
You can't optimize what you can't see. Know these for the test:
- Billing Export to BigQuery: Allows you to create custom dashboards in Looker Studio to find "hidden" costs.
- Budgets and Alerts: Set these at the project or billing account level to avoid nasty surprises.
- Quotas: Use them to prevent runaway costs in Dev/Test environments.
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