PCDE Practice Test 29 — 15 Questions

Question 1

You are designing a dashboard for application latency. You want to visualize the distribution of latency values across different services using a chart that shows percentiles over time. Which chart type should you use?

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

Accepted Answer

Heatmap chart. A heatmap chart can show the distribution of values over time, with color intensity representing count. It allows visualizing percentiles and patterns. Line charts show trends, stacked bar shows component totals, and scatter shows individual data points.

Answer

Scatter chart

Answer

Stacked bar chart

Answer

Line chart

Question 2

You need to set up a notification channel for alerting that triggers a PagerDuty incident. The PagerDuty integration key is 'abc123'. What is the correct command to create this channel?

Accepted Answer

gcloud alpha monitoring channels create --type=pagerduty --display-name="PagerDuty" --channel-labels=service_key=abc123. PagerDuty notification channels require the type 'pagerduty' and a 'service_key' (integration key) in the labels. The gcloud command is 'gcloud alpha monitoring channels create' with --type=pagerduty and --display-name and --channel-labels=service_key=... .

Answer

gcloud alpha monitoring channels create --type=slack --display-name="PagerDuty" --channel-labels=token=abc123

Answer

gcloud alpha monitoring channels create --type=pagerduty --display-name="PagerDuty" --channel-labels=auth_token=abc123

Answer

gcloud beta monitoring channels create --type=webhook --display-name="PagerDuty" --channel-labels=url=https://events.pagerduty.com/integration/abc123/enqueue

Question 3

A DevOps engineer needs to create a dashboard as code for Cloud Monitoring. They want to version-control the dashboard definition. Which method should they use?

Accepted Answer

Use the Cloud Monitoring API to create dashboards from a Terraform resource. Cloud Monitoring dashboards can be defined using the REST API or gcloud commands, and the JSON/YAML definition can be stored in version control.

Answer

Use gcloud alpha monitoring dashboards create command with a JSON file

Answer

Create the dashboard via the Cloud Console and export the JSON representation

Answer

Use Grafana with Cloud Monitoring data source and export dashboard JSON

Question 4

A company is building a business intelligence dashboard on BigQuery to analyze daily sales data. The table contains a TIMESTAMP column 'order_ts' and a string column 'region'. The BI team frequently filters by month and region. Which table design best optimizes query performance and cost?

Accepted Answer

Partition the table by date (month) and cluster by region. Partitioning the table by month (using the DATE_TRUNC function on order_ts) allows BigQuery to prune entire partitions when filtering by month, reducing the amount of data scanned and thus lowering cost. Clustering by region further organizes data within each partition, enabling efficient block-level pruning for region filters. This combination optimizes both query performance and cost for the BI team's common filter pattern.

Answer

Use a separate table for each region

Answer

Clustering by order_ts and region without partitioning

Answer

Partition the table by region and cluster by order_ts

Question 5

You need to set up an alert that fires when the total number of errors in a specific Cloud Logging log view exceeds 10 in any 5-minute window over the last 1 hour. Which combination of alerting policy conditions and log-based metric is appropriate?

Accepted Answer

Create a log-based counter metric and use a metric threshold condition with rolling window 5 minutes, threshold 10. To count errors from logs, you create a log-based counter metric. Then set an alert with condition type 'metric threshold', using the counter metric, with aggregation window '5 minutes', and trigger if value > 10. The 'condition absent' is for missing data, not threshold. 'Forecast' predicts future values. Standard configuration: log-based counter metric + metric threshold alert.

Answer

Use a forecast condition on the log-based metric to predict when errors will exceed 10

Answer

Use a logs-based alerting policy directly with a filter and set count > 10 in 5 minutes

Answer

Create a metric threshold alert on the log entry count metric with duration 5 minutes and threshold 10

Question 6

You need to send alert notifications to a Slack channel. Which TWO components are required?

Accepted Answer

A notification channel of type 'slack' in Cloud Monitoring. To send alerts to Slack, you need a Slack app with a webhook URL, and a Cloud Monitoring notification channel of type 'slack' configured with that webhook URL. Pub/Sub is not required for Slack directly; Slack channels are configured via webhooks. Email notification channel type is incorrect; Slack is a separate type. A Cloud Function could be used as an intermediary but is not required.

Answer

A Cloud Pub/Sub topic

Answer

An email notification channel

Answer

A Cloud Function to transform the alert

Question 7

A company is running analytical queries on large datasets (terabytes) that involve aggregations, joins, and window functions. The data is updated daily via batch loads. The queries must complete in seconds to minutes. Which Google Cloud database service is BEST suited for this workload?

Accepted Answer

BigQuery. BigQuery is a serverless data warehouse designed for large-scale analytics with fast SQL queries. It handles terabytes to petabytes, charges by query usage, and is ideal for OLAP workloads.

Answer

Cloud SQL for MySQL

Answer

Cloud Spanner

Answer

Bigtable

Question 8

Your Cloud Spanner instance has high latency for point reads. The workload is evenly distributed across all nodes. Which metric should you examine first to identify the bottleneck?

Accepted Answer

CPU utilization per node. High latency for point reads in Cloud Spanner, even with evenly distributed workload, often points to CPU saturation on individual nodes. Spanner uses a shared-nothing architecture where each node handles a portion of the data and queries; if CPU utilization per node is high, it indicates that the node is overloaded, causing queuing and increased latency. This metric directly reflects processing capacity and is the first place to look for a bottleneck in point-read performance.

Answer

Storage utilization

Answer

Rows returned per second

Answer

Number of committed nodes

Question 9

Your GKE cluster runs a stateful application that requires persistent storage. You want to use Vertical Pod Autoscaler (VPA) to optimize resource requests, but you notice that pods are being terminated and recreated when VPA updates resource recommendations. You want to avoid pod restarts. Which VPA updateMode should you use?

Accepted Answer

updateMode: Initial. VPA updateMode: Auto will evict and recreate pods to apply new resource limits. To avoid restarts, you can use Initial (applies only to new pods) or Off (no changes). The question asks to avoid pod restarts, so Initial is appropriate if you can accept that existing pods keep their old limits. Recreate is the same as Auto. Off disables VPA.

Answer

updateMode: Recreate

Answer

updateMode: Off

Answer

updateMode: Auto

Question 10

A company runs a GKE cluster for a web application. During peak traffic, the application experiences increased latency. The team has enabled the Horizontal Pod Autoscaler (HPA) based on CPU utilization, but the scaling is not fast enough. Which approach would improve the responsiveness of the HPA?

Accepted Answer

Decrease the HPA sync period from 15 seconds to 5 seconds.. Decreasing the HPA sync period makes the controller evaluate metrics more frequently, reducing the time to react to load changes. Increasing stabilization window delays scaling up, making it worse.

Answer

Decrease the CPU target utilization from 80% to 50%.

Answer

Increase the HPA sync period from 15 seconds to 60 seconds.

Answer

Increase the stabilization window from 5 minutes to 10 minutes.

Question 11

An online payment processing system uses Cloud SQL for MySQL with a 1 TB database. The system experiences high write throughput (~5000 writes/sec) and needs sub-10ms latency. The current instance has 8 vCPUs and 32 GB RAM. Which two metrics would indicate that the instance needs a larger tier? (Choose TWO.)

Accepted Answer

CPU utilization consistently above 80%.. Sustained CPU utilization above 80% indicates the instance is compute-bound, which can lead to queuing and increased latency for write operations. In Cloud SQL for MySQL, high CPU usage often means the instance lacks sufficient vCPUs to handle the write throughput, necessitating a larger tier with more CPU cores.

Answer

Memory usage is 50% of 32 GB.

Answer

Average query latency of 5 ms.

Answer

Network traffic is 100 Mbps.

Question 12

A startup uses Memorystore for Redis as a session store. They are concerned about losing session data if the instance fails. Which option provides the best durability for session data without significant application changes?

Accepted Answer

Configure a cross-region replica to provide high availability. Configuring a cross-region replica in Memorystore for Redis provides high availability and durability by replicating data asynchronously to a replica instance in a different region. If the primary instance fails, the replica can be promoted, minimizing session data loss without requiring significant application changes, as the application continues to connect to the same endpoint or a new primary endpoint.

Answer

Increase the maxmemory setting to store more data

Answer

Take regular snapshots of the instance using gcloud commands

Answer

Enable Redis persistence (RDB/AOF) on the Memorystore instance

Question 13

A company runs a Cloud SQL for PostgreSQL instance that is nearing its storage limit of 500 GB. The database administrator needs to increase storage capacity online without any downtime. What should they do?

Accepted Answer

Use the gcloud sql instances patch command with --storage-size flag. The `gcloud sql instances patch` command with the `--storage-size` flag allows you to increase the storage capacity of a Cloud SQL for PostgreSQL instance online without any downtime. Cloud SQL supports live storage increases by automatically resizing the underlying persistent disk while the instance remains available, so no restart or maintenance window is required.

Answer

Enable automatic storage increase and wait for it to trigger

Answer

Delete and recreate the instance with a larger disk

Answer

Shut down the instance, increase the disk size, and restart

Question 14

A team wants to automatically adjust the node count in a GKE cluster based on pending pod resource requests. Which component should they enable?

Accepted Answer

Cluster Autoscaler. The Cluster Autoscaler automatically adds or removes nodes from the cluster based on pending pods or underutilized nodes.

Answer

Vertical Pod Autoscaler

Answer

Node auto-provisioning

Answer

Horizontal Pod Autoscaler

Question 15

A company is running a Cloud SQL for MySQL instance and needs to create a read replica in a different region for disaster recovery. They also want to be able to promote the replica to a standalone instance if needed. Which three steps should they take? (Choose THREE.)

Accepted Answer

Enable binary logging on the primary instance. Cross-region replicas are created using the gcloud command with the --region flag and the --master-instance-name pointing to the primary. After creation, replication must be verified. If needed, the replica can be promoted using gcloud sql instances promote-replica.

Answer

Set the replica's database flags to enable read-only mode

Answer

Create the replica in the same region as the primary