PCDOE Optimizing performance and cost — Timed 10 Questions

Question 1

A company runs a batch processing workload on Compute Engine that runs for 3 hours every night. They want to minimize costs while ensuring the job completes reliably. Which recommendation should they follow?

10 minute time limit — choose an answer to begin.

Accepted Answer

Use preemptible VMs and design the job to handle interruptions gracefully.. Preemptible VMs cost about 60-80% less than standard VMs and are ideal for batch workloads that can tolerate interruptions. Since the job runs for only 3 hours nightly, it can be designed to checkpoint progress and restart from the last checkpoint if a preemptible VM is terminated (which can happen at any time within 24 hours). This minimizes cost while ensuring reliability through graceful interruption handling.

Answer

Use sole-tenant nodes to isolate the workload.

Answer

Use standard (on-demand) VMs and enable sustained use discounts.

Answer

Purchase 1-year committed use discounts for the VMs.

Question 2

A company wants to control costs by limiting the maximum number of Compute Engine instances a project can create. Which TWO methods can achieve this? (Choose two.)

Accepted Answer

Set resource quotas for compute instances.. Resource quotas are the only method among the options that can limit the maximum number of instances by setting a hard cap on instance count. IAM conditions can restrict instance creation based on attributes like machine type or region but cannot enforce a numeric limit on the number of instances. Therefore, only option D is correct.

Answer

Use IAM conditions to restrict instance creation.

Answer

Enable preemptible VMs.

Answer

Create budget alerts with a threshold at 80% of budget.

Answer

Apply committed use discounts.

Question 3

A company stores historical log data in Cloud Storage. The logs are accessed rarely after 30 days. They want to reduce storage costs while maintaining immediate access for occasional audits over the next year. What should they use?

Accepted Answer

Standard class storage with a lifecycle policy to transition to Nearline after 30 days and to Coldline after 90 days. It uses lifecycle policies to transition to Nearline after 30 days and Coldline after 90 days, balancing cost and immediate access for occasional audits. Option B (Nearline) is more expensive than using lifecycle transitions. Option C (Coldline with delete after 1 year) deletes data and does not offer the same cost savings over the year. Option D (Archive) has higher retrieval costs and longer access times, making it less suitable for occasional audits.

Answer

Nearline class storage

Answer

Coldline class storage with a lifecycle policy to delete after 1 year

Answer

Archive class storage

Question 4

A company has a steady-state workload of 100 vCPUs running 24/7. They want to get the maximum discount possible without long-term commitment. What discount should they expect?

Accepted Answer

Sustained use discount of up to 30%. Sustained use discounts are automatically applied to instances that run for a significant portion of a month. For each instance family and region, the discount increases as usage increases, reaching a maximum of 30% discount for instances running the entire month. Since the workload runs 24/7 on 100 vCPUs, the maximum discount without any commitment is 30% via sustained use. Option A describes committed use discounts, which require a 1- or 3-year commitment and can be up to 57% for some resources, but the question specifies without long-term commitment. Option B is incorrect because sustained use discounts can go up to 30%, not 20%. Option D is incorrect because discounts are available.

Answer

Committed use discount of up to 57%

Answer

Sustained use discount of up to 20%

Answer

No discount available

Question 5

Refer to the exhibit. A budget alert has fired for project dev-123 indicating that the cost has exceeded the budget of $1000. What should the team do next to investigate the cost overrun?

Accepted Answer

Open a BigQuery query on the billing export table, filtering by project 'dev-123' and service.. The most effective first step is to query the billing export data in BigQuery, which provides detailed cost breakdowns by project, service, and labels. Option B is the recommended approach for granular analysis. Viewing the billing account's cost table in the Cloud Console (D) gives a high-level view but not the necessary detail. Creating a new budget with a lower threshold (E) does not address the root cause. Disabling all APIs (A) is too drastic without understanding the cause. Setting up a Cloud Function to automatically shut down resources (C) is a reaction that should follow investigation.

Answer

Disable all APIs in project dev-123 immediately.

Answer

Set up a Cloud Function to automatically shut down resources when the budget is exceeded.

Answer

View the billing account's cost table in the Cloud Console.

Answer

Create a new budget with a lower threshold to get alerted earlier.

Question 6

A company is using Google Kubernetes Engine (GKE) with multiple node pools. They notice that their monthly costs are higher than expected. Upon review, they find that several preemptible VMs are being recreated frequently, leading to sustained usage costs. What is the most cost-effective solution to reduce costs?

Accepted Answer

Migrate to Spot VMs, which have a lower price and no maximum runtime.. Spot VMs are the recommended replacement for preemptible VMs, offering the same low price but without the 24-hour maximum runtime limit. This eliminates the frequent recreation and sustained usage costs caused by preemptible VMs being terminated and restarted, directly reducing monthly expenses.

Answer

Purchase committed use discounts for the preemptible VMs.

Answer

Increase the number of preemptible VMs to spread the workload.

Answer

Enable sustained use discounts for the existing VMs.

Question 7

A company uses Cloud Storage to store archival data. They want to minimize storage costs while maintaining availability. Which storage class should they use?

Accepted Answer

Archive storage class.. The Archive storage class is the correct choice because it offers the lowest storage cost for archival data that is accessed less than once per year, with a 365-day minimum storage duration and retrieval costs that are higher than other classes. This aligns with the requirement to minimize storage costs while maintaining availability, as Archive data is still available for retrieval (though with a longer latency) and is replicated for durability.

Answer

Nearline storage class.

Answer

Standard storage class.

Answer

Coldline storage class.

Question 8

A company is using BigQuery for analytics and wants to control costs. They have many queries that scan large amounts of data. Which approach is most effective in reducing query costs?

Accepted Answer

Partition tables by date and use partition pruning in queries.. Partitioning tables by date and using partition pruning in queries directly reduces the amount of data scanned by BigQuery, which is the primary driver of on-demand query costs. By filtering on the partition column, BigQuery can skip entire partitions that do not match the query criteria, minimizing the bytes processed. This is the most effective cost-control measure because it addresses the root cause of high costs—excessive data scanning—without requiring a pricing model change or additional resource commitments.

Answer

Switch to flat-rate pricing to cap costs.

Answer

Reserve BigQuery slots for dedicated capacity.

Answer

Use clustering to organize data within partitions.

Question 9

A company uses Cloud CDN to deliver content globally. They notice increasing egress costs. Which change will most effectively reduce egress costs?

Accepted Answer

Configure Cloud CDN to cache more content and increase cache hit ratio.. Increasing the cache hit ratio reduces the number of requests that reach the origin server, which directly lowers the volume of data transferred from the origin to the CDN edge. Since egress costs are primarily driven by data served from the CDN edges to users, caching more content at the edge minimizes the need to fetch and serve data from the origin, thereby reducing overall egress traffic and associated costs.

Answer

Switch to a premium tier network for lower egress rates.

Answer

Enable gzip compression for all responses.

Answer

Use Cloud Armor to block malicious traffic.

Question 10

A company is using Google Cloud and wants to monitor and control costs. Which TWO actions should they take? (Choose two.)

Accepted Answer

Set up budget alerts to notify when spending exceeds thresholds.. Setting up budget alerts (option A) is a core cost control action because it allows you to define a budget amount and receive notifications when actual or forecasted spending exceeds a specified threshold (e.g., 50%, 90%, 100%). This enables proactive intervention before costs spiral out of control. Using labels (option B) to categorize resources (e.g., by team, project, or environment) allows you to track and allocate costs accurately in billing reports, making it easier to identify cost drivers and enforce accountability.

Answer

Disable all unnecessary APIs at the organization level.

Answer

Export billing data to BigQuery for detailed analysis.

Answer

Grant billing account access to all project owners.