PCDE Practice Test 11 — 15 Questions

Question 1

Which notification channel can be used with Cloud Monitoring to trigger a custom workflow in Cloud Functions when an alert fires?

Accepted Answer

Cloud Pub/Sub. Cloud Pub/Sub is the native notification channel in Cloud Monitoring that can directly trigger a Cloud Function when an alert fires. By configuring a Pub/Sub notification channel, alert payloads are published to a topic, and a Cloud Function subscribed to that topic executes the custom workflow. This is the standard event-driven integration pattern in Google Cloud.

Answer

Slack via Pub/Sub

Answer

PagerDuty

Answer

Email

Question 2

Refer to the exhibit. The BI team creates a view to summarize sales. When they query the view with an additional WHERE clause on region, they notice that the underlying query still processes the same amount of data regardless of the filter. What is the most likely reason?

Accepted Answer

The view is a logical view, not a materialized view, so filters on the view do not reduce the scanned data.. A logical view (also known as a standard or non-materialized view) in BigQuery does not store data; it merely stores the SQL query definition. When you query a logical view with an additional WHERE clause, BigQuery does not automatically push that filter down into the view's underlying query unless the view is defined with a specific optimization like a parameterized view or uses a scripting approach. By default, the view's query is executed first, and then the outer filter is applied to the result set, meaning the same amount of underlying data is scanned regardless of the outer filter.

Answer

The view is a materialized view that refreshes every 30 minutes.

Answer

The view's WHERE clause on date is too restrictive, causing a full scan.

Answer

The view uses authorized views, which prevent predicate pushdown.

Question 3

A developer wants to deploy a containerized application to Cloud Run using the command line. They need to set the maximum number of concurrent requests per container instance to 80. Which flag should they use with 'gcloud run deploy'?

Accepted Answer

--concurrency. The `--concurrency` flag in `gcloud run deploy` directly sets the maximum number of simultaneous requests that a single container instance can handle. By specifying `--concurrency=80`, the developer limits each instance to processing up to 80 concurrent requests, which helps control resource usage and scaling behavior in Cloud Run.

Answer

--platform

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--cpu-throttling

Answer

--max-instances

Question 4

What is the primary purpose of an error budget?

Accepted Answer

To balance reliability and innovation by allowing a controlled amount of failure. An error budget is the inverse of a service level objective (SLO): if the SLO is 99.9% availability, the error budget is the remaining 0.1% of allowed unreliability. Its primary purpose is to balance reliability work against feature velocity by giving teams a quantified, agreed-upon amount of acceptable failure. When the budget is exhausted, teams typically freeze releases and focus on reliability; when it is healthy, they can take more risks and innovate.

Answer

To measure team performance for annual reviews

Answer

To define the maximum acceptable downtime in a contract

Answer

To track the total number of errors in a system

Question 5

A company uses Artifact Registry to store Docker images. They want to enforce that only images signed by a trusted authority can be deployed to their GKE cluster. Which service should they use with Artifact Registry?

Accepted Answer

Binary Authorization. Binary Authorization is a GKE deploy-time security control that enforces attestations on container images before they are admitted to the cluster. By integrating with Artifact Registry and Container Analysis, it verifies that images are signed by a trusted authority (via attestors and cryptographic signatures) and blocks unsigned or unverified images from being deployed. This directly satisfies the requirement to allow only trusted, signed images on GKE.

Answer

Identity and Access Management (IAM)

Answer

Container Analysis

Answer

Cloud Build

Question 6

Your application uses structured logging in JSON format. You want to ensure that each log entry is automatically correlated with the corresponding trace in Cloud Trace. Which field must be included in the JSON payload?

Accepted Answer

"trace" field with the trace ID formatted as projects/PROJECT_ID/traces/TRACE_ID. To correlate a structured log entry with a Cloud Trace span, the JSON payload must include a 'trace' field whose value is the full trace resource name in the format projects/PROJECT_ID/traces/TRACE_ID. Cloud Logging uses this field to link the log entry to the trace, enabling the 'View trace' link in the Logs Explorer. The trace ID alone is not sufficient; the project-qualified path is required.

Answer

"severity" field set to "ERROR"

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"httpRequest" object with requestUrl and status

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"labels" field containing custom metadata

Question 7

A Cloud SQL for PostgreSQL instance is running out of storage. The engineer wants to configure automatic storage increase to avoid manual intervention. What should they do?

Accepted Answer

Use gcloud sql instances patch with the --storage-auto-increase flag.. Cloud SQL for PostgreSQL supports automatic storage increase, which can be enabled via the `--storage-auto-increase` flag in the `gcloud sql instances patch` command. This feature automatically increases the instance's storage capacity when it approaches the configured limit, eliminating the need for manual intervention.

Answer

Use gcloud sql instances patch with the --disk-size flag to set a larger size.

Answer

Create a cron job to monitor disk usage and increase storage via API.

Answer

Use gcloud sql instances create to create a new instance with larger storage.

Question 8

Your organization uses Cloud SQL for PostgreSQL for a reporting application with read-heavy workloads. Queries are slow and you need to reduce load on the primary instance. You also need to ensure that all read queries from the reporting tool are isolated from the primary. What should you do?

Accepted Answer

Create a Cloud SQL read replica, and configure the reporting tool to connect to the replica's IP address.. A Cloud SQL read replica is a continuously updated copy of the primary that serves read-only traffic, so pointing the reporting tool at the replica's IP isolates read queries from the primary and reduces its load. This directly satisfies both the performance and isolation requirements for read-heavy reporting workloads.

Answer

Create a Cloud SQL clone and point the reporting tool to the clone.

Answer

Enable connection pooling using Cloud SQL Auth Proxy and PgBouncer on the primary instance.

Answer

Configure the reporting tool to use the primary instance with a lower priority.

Question 9

An engineer wants to cache Docker layers in Cloud Build to speed up subsequent builds. The build uses Kaniko to build images. What should they include in the cloudbuild.yaml?

Accepted Answer

Set `--cache=true` and `--cache-repo` in the Kaniko builder arguments. Kaniko is a container image builder that runs inside a container without requiring a Docker daemon, and it supports layer caching natively through the `--cache=true` flag combined with `--cache-repo` pointing to a registry repository where intermediate layers are stored. When these flags are set in the Kaniko builder arguments within cloudbuild.yaml, Kaniko checks the cache repo for existing layers and reuses them, dramatically speeding up subsequent builds. This is the documented Google-recommended approach for caching Kaniko builds in Cloud Build.

Answer

Add a step that runs `docker save` and `docker load`

Answer

Use the `docker` builder instead of Kaniko and set `--cache-from`

Answer

Enable Cloud Build's built-in caching by setting `cache: true` in cloudbuild.yaml

Question 10

A Cloud Spanner database uses a sequential customer ID as the primary key, causing frequent hotspotting on a single split. The team needs to eliminate hotspots. Which key design should they implement?

Accepted Answer

Add a hash prefix derived from the customer ID. Cloud Spanner splits data by primary key ranges, and a monotonically increasing key (like a sequential customer ID) sends all new writes to the last split, creating a hotspot. Adding a hash prefix derived from the customer ID distributes writes across many splits because the hash value is effectively random, spreading insert load evenly. This is the canonical Google-recommended pattern for high-write tables with sequential business keys.

Answer

Use a composite key with a monotonically increasing timestamp as the first part

Answer

Use a random UUID as the primary key

Answer

Keep the sequential key but add a secondary index

Question 11

A DevOps team is deploying a web application on Google Kubernetes Engine (GKE) that experiences daily traffic spikes. They want to automatically adjust the number of pod replicas based on CPU utilization. Which Kubernetes resource should they use?

Accepted Answer

Horizontal Pod Autoscaler (HPA). The Horizontal Pod Autoscaler (HPA) automatically scales the number of pod replicas based on resource utilization metrics like CPU or memory. The Vertical Pod Autoscaler (VPA) adjusts resource requests/limits, not replica count. Cluster Autoscaler adjusts node count, not pods. PodDisruptionBudget controls voluntary disruptions.

Answer

Cluster Autoscaler

Answer

PodDisruptionBudget

Answer

Vertical Pod Autoscaler (VPA)

Question 12

An engineer needs to create a backup of a Cloud SQL for MySQL instance that is retained for 400 days to meet compliance requirements. What is the correct approach?

Accepted Answer

Use Cloud SQL export to Cloud Storage and store the export for 400 days using object lifecycle management.. Cloud SQL for MySQL allows automated backups with a maximum retention of 365 days. To retain a backup for longer, the engineer must create an on-demand export to Cloud Storage. The export can be stored indefinitely. Automated backup retention cannot be extended beyond 365 days. Using Cloud SQL's backup retention setting to 400 days is not supported. Using a read replica is not a backup. Using PITR does not create a separate backup file.

Answer

Set the backup retention to 400 days in the Cloud SQL instance settings.

Answer

Create a cross-region read replica and use it as a backup source.

Answer

Use the gcloud command: gcloud sql backups create --instance=myinstance --async and rely on default retention.

Question 13

A global e-commerce platform needs a database that supports strong consistency across multiple continents and can handle high write throughput. Which database service should they choose?

Accepted Answer

Cloud Spanner. Cloud Spanner is the correct choice because it provides globally distributed, strongly consistent relational database service with synchronous replication across regions and continents, supporting external consistency and high write throughput via TrueTime and Paxos-based consensus. This meets the requirement for strong consistency across multiple continents and high write throughput, which is not achievable with traditional single-region or eventually consistent databases.

Answer

Cloud SQL for PostgreSQL

Answer

Cloud Firestore

Answer

Cloud Bigtable

Question 14

A Cloud Bigtable instance is experiencing high read latency due to hot spots. The operations team uses the Key Visualizer tool and identifies that a small set of row keys are being read disproportionately. Which action should they take to mitigate the hot spotting?

Accepted Answer

Redesign the row key scheme to distribute the workload across more tablets.. Hot spotting in Cloud Bigtable is typically caused by a suboptimal row key design that concentrates read/write traffic on a small number of tablets. Redesigning the row key scheme to distribute the workload—for example, by adding a hash prefix or using a more granular key—spreads requests across multiple tablets, alleviating the hotspot. Key Visualizer explicitly identifies the skewed row keys, guiding the redesign effort.

Answer

Increase the number of nodes in the Bigtable cluster to handle the load.

Answer

Change the storage type from HDD to SSD to improve performance.

Answer

Enable replication across multiple zones.

Question 15

An e-commerce platform uses Cloud Bigtable for real-time analytics on customer behavior. The table uses a row key of 'customer_id#timestamp' (customer ID followed by reverse timestamp). Queries for a specific customer's recent events are fast, but queries that filter by event type (e.g., 'purchase') across many customers are slow. What schema change can improve query performance for event-type filtering?

Accepted Answer

Change the row key to 'event_type#customer_id#timestamp'.. Cloud Bigtable's performance depends heavily on row key design for efficient scans. By changing the row key to 'event_type#customer_id#timestamp', queries filtering by event type can use a single row key prefix scan, which is fast and avoids full table scans. This leverages Bigtable's lexicographic ordering to group all events of the same type together, making event-type filtering a range scan rather than a filter across unrelated rows.

Answer

Create a separate column family for each event type.

Answer

Add a secondary index on the event_type column.

Answer

Use a separate Bigtable instance for each event type.