PCDOE Optimizing performance and cost Practice Test 4 — 15 Questions

Question 1

A company uses Cloud Storage with standard storage class for all data. They want to automatically move data that has been accessed more than 30 days ago to a lower-cost storage class, and after 90 days to archive. What should they configure?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Lifecycle management rules.. Lifecycle management rules in Cloud Storage allow you to define conditions based on object age, and automatically transition objects to colder storage classes like Nearline, Coldline, or Archive. The question specifies moving data that hasn't been accessed for 30 days to a lower-cost class and after 90 days to archive, which is exactly what lifecycle rules do. You can set multiple rules with age conditions (e.g., age: 30, action: SetStorageClass Nearline; age: 90, action: SetStorageClass Archive). No other option provides automated storage class transitions based on time.

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Bucket lock.

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Retention policy.

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Object versioning.

Question 2

Which GCP tool provides recommendations for rightsizing Compute Engine VMs?

Accepted Answer

Recommender.. The Recommender tool in GCP uses machine learning to analyze historical usage patterns and provides actionable recommendations, including rightsizing suggestions for Compute Engine VMs. It identifies underutilized VMs and suggests optimal machine types to reduce costs without compromising performance, making it the correct choice for this task.

Answer

Cloud Console Cost Table.

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Cloud Monitoring.

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Cloud Billing Reports.

Question 3

A team uses Cloud SQL for MySQL. They have read-heavy traffic and want to reduce costs. Which strategy is most effective?

Accepted Answer

Use read replicas to offload read queries.. Read replicas offload read queries from the primary instance, allowing the primary to focus on writes and reducing the load on the more expensive primary instance. This is the most effective cost-reduction strategy for read-heavy workloads because read replicas can be smaller or use cheaper tiers, and they scale horizontally. Offloading reads also improves performance without increasing the primary's size.

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Use committed use discounts.

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Use High Availability with a standby instance.

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Use vertical scaling to increase instance size.

Question 4

What is the primary benefit of using preemptible VMs?

Accepted Answer

Lower cost.. Preemptible VMs are Compute Engine instances that last a maximum of 24 hours and can be terminated at any time by Google. They offer a significantly lower price—up to 60-91% discount compared to standard VMs—making them ideal for batch jobs and fault-tolerant workloads where cost savings are the primary benefit.

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Higher reliability.

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Faster performance.

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Better security.

Question 5

Which THREE actions can help optimize Cloud Storage costs? (Choose three.)

Accepted Answer

Use Nearline or Coldline storage classes for infrequently accessed data.. Nearline and Coldline storage classes are designed for infrequently accessed data, offering lower storage costs compared to Standard storage. By choosing these classes for data that is accessed less than once a quarter or once a year, you reduce the per-GB storage charge, though you incur higher retrieval and early deletion fees. This directly optimizes costs when access patterns align with the class's intended use.

Answer

Enable versioning on all buckets to protect against accidental deletion.

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Use Standard storage class for all objects to ensure low latency.

Question 6

A company uses BigQuery on-demand pricing. They want to reduce costs without changing usage patterns. Which THREE strategies are effective? (Choose three.)

Accepted Answer

Use clustered tables.. Option A (Use clustered tables) is correct because clustering physically sorts data by the specified columns, so queries with filters or aggregations on those columns scan fewer bytes, and BigQuery on-demand pricing bills by bytes processed. Option B (Use materialized views) is correct because they precompute and cache query results, so repeated queries against the materialized view read far less data than re-scanning the base tables, directly lowering on-demand bytes-billed. Option E (Use partitioned tables) is correct because partitioning lets BigQuery prune irrelevant partitions, so queries filtering on the partition column scan only the needed partitions instead of the whole table. Option C (legacy SQL) is not correct because legacy SQL does not inherently reduce bytes processed and standard SQL is the recommended, more capable dialect. Option D (flat-rate pricing) is not correct because it changes the pricing model to reserved slots rather than reducing cost under the existing on-demand model, and the scenario specifies on-demand pricing without changing usage patterns.

Answer

Use legacy SQL instead of standard SQL.

Answer

Use flat-rate pricing.

Question 7

Refer to the exhibit. What does this recommendation suggest?

Accepted Answer

Upgrade the instance.. The recommendation shown in the exhibit (a Google Cloud recommender for Compute Engine) indicates that the instance is under-provisioned relative to its workload — typically flagged as 'overutilized' or 'change machine type' — so the suggested action is to upgrade the instance to a larger machine type. Recommenders analyze CPU, memory, and other metrics over time and surface rightsizing suggestions; an upgrade recommendation means the current shape is too small.

Answer

Change the instance to preemptible.

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Delete the instance.

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Downgrade the instance.

Question 8

A startup wants to reduce their Google Cloud costs for a batch processing job that runs nightly for 3 hours. The job is fault-tolerant and can tolerate interruptions. What is the most cost-effective compute option?

Accepted Answer

Preemptible VM. Preemptible VMs (Option D) are the most cost-effective because they offer up to 60-91% discount and are suitable for fault-tolerant, interruptible batch jobs. Standard VMs (Option A) are more expensive. Shielded VMs (Option B) provide security features but no cost savings. Sole-tenant nodes (Option C) provide isolation but are more costly.

Answer

Standard VM

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Shielded VM

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Sole-tenant node

Question 9

A DevOps engineer is reviewing GCP costs and notices high network egress charges. Which two actions can help reduce network egress costs? (Choose two.)

Accepted Answer

Use Cloud CDN to cache content closer to users. Option C is correct because Cloud CDN caches content at Google's globally distributed edge points of presence, so repeated requests are served from an edge location near the user instead of traversing the network from the origin, which directly reduces egress traffic and its associated charges. Option D is correct because keeping communicating resources in the same region means traffic between them stays on Google's internal network and is billed at lower intra-region rates (or is free for same-zone traffic), avoiding costly inter-region egress. Option A is wrong because preemptible VMs reduce compute costs, not network egress charges. Option B is wrong because consolidating workloads into a single zone does not by itself reduce egress and can harm availability; egress is driven by where traffic exits to users or crosses regions, not by zone count. Option E is wrong because external global load balancers distribute traffic globally and can increase egress by routing responses across regions rather than reducing egress costs.

Answer

Use preemptible VMs

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Migrate all workloads to a single zone

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Use external load balancers with global access

Question 10

A company wants to set budgets and alerts for a GCP project. Which two steps are required to enable budget notifications via email? (Choose two.)

Accepted Answer

Create a budget alert threshold in the Cloud Console. Options B and C are required. You must create a budget alert threshold in the Cloud Console to define the spending limit, and then add email recipients in the budget configuration to receive notifications. Option A (Enabling the Cloud Billing API) is not a prerequisite for email notifications; it is needed for programmatic access. Options D and E are for programmatic notifications, not email.

Answer

Enable the Cloud Billing API for the project

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Create a Pub/Sub topic and subscribe to it

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Set up a Cloud Function to send emails

Question 11

An organization wants to optimize BigQuery costs. Which three practices should they implement? (Choose three.)

Accepted Answer

Set a maximum bytes billed per query at the project level. Option B is correct because setting a maximum bytes billed per query at the project level enforces a hard cap that causes queries exceeding the limit to fail, preventing runaway scan costs from accidental or inefficient queries. Option C is correct because partitioning (e.g., by ingestion time, DATE, or TIMESTAMP column) and clustering (sorting data by specified columns) prune the data scanned, and BigQuery on-demand pricing is based on bytes processed, so less data scanned directly lowers cost. Option E is correct because authorized views grant access to underlying data without duplicating it into additional datasets or tables, avoiding extra storage charges and redundant data copies. Option A is not correct because storing data in many unpartitioned daily tables increases management overhead and does not reduce bytes scanned, since queries cannot prune data efficiently. Option D is not correct because flat-rate reservations are a capacity commitment that is not universally cheaper; they only make sense for predictable, high-volume workloads, not as a blanket cost-optimization practice for all queries.

Answer

Store data in multiple tables per day without partitioning

Answer

Purchase BigQuery flat-rate reservations for all queries

Question 12

A company uses BigQuery on-demand pricing. To control costs, they want to prevent any single query from scanning more than 1 TB of data. How can they enforce this?

Accepted Answer

Use the maximum bytes billed parameter in the query settings. The maximum bytes billed parameter is a per-query setting in BigQuery that causes the query to fail if the estimated bytes to be scanned exceed the specified limit. This directly enforces a hard cap on data scanned per query, preventing any single query from processing more than 1 TB. It is available in the query settings of the BigQuery UI, bq command-line tool, and API, and is the intended mechanism for cost control at the query level.

Answer

Set a custom cost budget with alert at 1 TB

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Use BigQuery reservations with 1 TB slot capacity

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Set a query quota in the GCP Console quota page

Question 13

A DevOps engineer is responsible for cost optimization of GKE clusters. They have identified that many nodes are underutilized. What is the best approach to reduce costs without impacting availability?

Accepted Answer

Enable cluster autoscaler to automatically scale down nodes. Enabling the cluster autoscaler allows GKE to automatically adjust the number of nodes in a node pool based on resource demands. When nodes are underutilized, the autoscaler can scale down the cluster by removing unnecessary nodes, thereby reducing costs without impacting availability because it ensures that pods can still be scheduled on remaining nodes. This is the recommended approach for cost optimization while maintaining availability.

Answer

Use spot VMs for all node pools

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Delete underutilized nodes manually

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Migrate to a single zone cluster

Question 14

A data processing company runs nightly batch jobs that can tolerate interruptions. They want to minimize compute costs. Which compute option should they use?

Accepted Answer

Preemptible VMs. Preemptible VMs are the correct choice because they offer the lowest cost for interruptible workloads. They are priced significantly lower than standard VMs (up to 80% discount) but can be terminated by Google Cloud at any time, with a 30-second warning, and have a maximum lifetime of 24 hours. Since the batch jobs can tolerate interruptions, preemptible VMs align perfectly with the cost-minimization goal.

Answer

VMs with committed use discounts

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Standard VMs with sustained use discounts

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Sole-tenant nodes

Question 15

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 a lifecycle policy to automatically transition objects from Standard to Nearline after 30 days and then to Coldline after 90 days, which reduces cost as access frequency drops while still providing immediate (millisecond) access for occasional audits throughout the year. Nearline and Coldline both offer low-latency access with no retrieval delay, so the data remains available for audits. Option B (Nearline only) would not optimize costs for data older than 90 days that could move to cheaper Coldline. Option C (Coldline with deletion after 1 year) risks losing data needed for audits and does not tier from Standard. Option D (Archive) is unsuitable because Archive has retrieval latency of hours, violating the immediate-access requirement.

Answer

Nearline class storage

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

Answer

Archive class storage