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CCNA Pcdoe Reliability Dr Questions

75 questions · Pcdoe Reliability Dr topic · All types, answers revealed

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1

MCQmedium

A global e-commerce platform uses Cloud Spanner multi-region configuration. The compliance team mandates that all write transactions must be committed in a specific geographic region to comply with data sovereignty laws. Which Spanner feature should be used to enforce this requirement?

A.Enable customer-managed encryption keys (CMEK)

B.Use read-only replicas in the required region

C.Deploy a regional instance in the required region

D.Set the default leader region to the required region

AnswerD

The leader region option ensures all writes are processed in that region, controlling where data is committed.

Why this answer

Spanner's leader region configuration allows you to designate a specific region where all write transactions are coordinated. This ensures that the commit timestamp and transaction processing occur within that region, helping meet data sovereignty requirements.

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2

MCQhard

A company runs a Cloud Bigtable instance with a single cluster in us-central1. They want to implement a disaster recovery plan that meets an RPO of 5 minutes and an RTO of 10 minutes in case of a regional outage. Which actions should they take?

A.Use Bigtable replication with 'read-failover' routing policy and use Cloud Functions to failover

B.Use Cloud SQL for MySQL with cross-region replica for better RPO

C.Create a scheduled backup every 5 minutes to Cloud Storage and restore in another region on failure

D.Add a second cluster in a different region, configure replication, and use 'any-replica' routing policy

AnswerD

A second cluster with asynchronous replication can achieve RPO of minutes. The 'any-replica' routing policy automatically sends requests to the available cluster, enabling failover in minutes.

Why this answer

Bigtable replication allows you to add a second cluster in a different region. Replication is asynchronous, so RPO depends on replication lag. With proper configuration and low write load, RPO can be as low as seconds, but typically a few minutes.

To achieve RPO of 5 minutes, you need to monitor replication lag. For RTO of 10 minutes, you need automatic failover. You can use 'any-replica' routing to automatically route requests to the secondary cluster if the primary is down.

However, failover is not instantaneous; there is a detection delay. But with proper health checks and DNS, it can be achieved. The simplest approach is to add a second cluster in a different region and use 'any-replica' routing policy (or cluster-group routing).

Using Cloud DNS with health checks is also valid but adds complexity.

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3

MCQeasy

A Cloud SQL for PostgreSQL instance needs to achieve a recovery point objective (RPO) of less than 1 minute and a recovery time objective (RTO) of less than 2 minutes in the event of a zone failure. Which disaster recovery strategy should be used?

A.Perform regular backups to Cloud Storage and restore in a different zone.

B.Enable cross-region replication using a read replica.

C.Enable point-in-time recovery (PITR) with transaction log backups.

D.Configure Cloud SQL HA (high availability) with a standby in a different zone.

AnswerD

Cloud SQL HA provides automatic failover to a standby in a different zone within same region, RPO near zero, RTO <60 seconds, meeting both requirements.

Why this answer

Cloud SQL HA configuration provides automatic failover to a standby in a different zone within the same region, with RPO near zero and RTO typically under 60 seconds. Cross-region read replicas have RPO equal to replication lag (could be minutes) and RTO of minutes due to manual promotion. Cross-region backup restore has RPO equal to backup age (hours) and RTO of hours.

Point-in-time recovery (PITR) is for within-region data recovery, not zone failure failover.

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4

Multi-Selectmedium

A company runs a Cloud Bigtable instance with two clusters in separate regions for disaster recovery. They want to ensure that read requests automatically use the secondary cluster if the primary cluster becomes unhealthy. Which two steps should they take? (Choose two.)

Select 2 answers

A.Change the routing policy to 'cluster-group routing' (any-replica)

B.Ensure the application uses the 'any-replica' routing policy in the client configuration

C.Set up a load balancer in front of Bigtable instances

D.Create a third cluster in a third region for quorum

E.Configure Cloud DNS with a health check that points to the secondary cluster

AnswersA, B

Cluster-group routing automatically sends reads to any available cluster, providing failover.

Why this answer

To enable automatic failover for reads in Bigtable, you need to use a routing policy that distributes reads across clusters. The 'cluster-group routing' (also called 'any-replica' routing) automatically routes requests to the nearest healthy cluster. Additionally, you must configure the application to use this routing policy.

Alternatively, you can use a load balancer with health checks, but that is not native to Bigtable. The correct native approach is to use cluster-group routing and ensure the application uses it.

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5

MCQeasy

An application running on Compute Engine needs a relational database with high availability across zones within a single region. The application requires an RTO of less than 30 seconds and RPO of zero. Which database solution meets these requirements?

A.AlloyDB

B.Cloud Bigtable with replication

C.Cloud SQL for MySQL with HA configuration

D.Cloud Spanner multi-region

AnswerA

AlloyDB provides automatic failover in less than 30 seconds and near-zero RPO, meeting both requirements.

Why this answer

AlloyDB provides automatic failover with RTO of less than 30 seconds and near-zero data loss (RPO ~0). It replicates data synchronously within a primary and read pool across zones in the same region. Cloud SQL HA has RTO <60 seconds, which does not meet the <30 second requirement.

Spanner multi-region is overkill and has higher cost. Bigtable does not support SQL and has eventual consistency.

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6

MCQmedium

A healthcare company uses Cloud SQL for PostgreSQL and needs to meet a disaster recovery requirement of RPO = 1 hour and RTO = 2 hours for a cross-region failover. They currently have a cross-region read replica in another region. Which additional action should they take to meet the RPO consistently?

A.Configure the read replica to use synchronous replication

B.Increase the replica's storage capacity

C.Set up monitoring and alerting on the replication lag metric

D.Enable point-in-time recovery on the primary instance

AnswerC

Monitoring the replication lag ensures that if the lag approaches 1 hour, the team can take corrective action to maintain the RPO.

Why this answer

Cross-region read replicas have asynchronous replication lag, which can vary. To ensure that the RPO is bounded to 1 hour, the company must monitor the replication lag and alert if it exceeds 1 hour. They can also increase the replica's resources to reduce lag, but monitoring is essential to guarantee the RPO.

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7

MCQeasy

A company needs to ensure that their Cloud SQL for PostgreSQL instance can recover from a zonal failure within 60 seconds with minimal data loss. Which feature should they enable?

A.Automated backups with PITR

B.Cross-region read replica

C.Enable deletion protection

D.High availability (HA) configuration

AnswerD

HA provides automatic zonal failover with RTO <60 seconds and near-zero data loss.

Why this answer

Cloud SQL HA configuration automatically fails over to a standby instance in a different zone within the same region. This failover is automatic and typically completes in under 60 seconds, with near-zero data loss (synchronous replication). Cross-region replicas are manual and have longer RTO.

Backups are not suitable for quick recovery.

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8

MCQmedium

An organization needs a multi-region database deployment with strong consistency and an RPO of zero in normal operation. They expect a regional outage and require automatic failover within seconds. Which database service and configuration meets these requirements?

A.Cloud Firestore in multi-region mode

B.Cloud Bigtable with multi-cluster routing and replication

C.Cloud SQL with cross-region read replica

D.Cloud Spanner multi-region configuration

AnswerD

Spanner multi-region provides synchronous replication across regions, zero RPO, and automatic failover within seconds.

Why this answer

Cloud Spanner multi-region configurations provide strong consistency, zero RPO during normal operation, and automatic failover within <1 minute (typically seconds) in case of regional failure.

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9

MCQmedium

A company needs to perform disaster recovery testing for their Cloud SQL for PostgreSQL instance. They want to validate that a cross-region failover works without affecting production. What is the BEST approach?

A.Promote a cross-region read replica to a standalone instance in the same project and test connectivity.

B.Create a clone of the primary instance in another region and test failover to the clone.

C.Use the gcloud sql instances failover command on the primary instance.

D.Stop the primary instance and promote the read replica, then later re-promote the original primary.

AnswerA

Promoting a read replica creates a new primary instance without affecting the original primary. This is a safe way to test failover.

Why this answer

A read replica can be promoted to a standalone instance, which does not affect the primary instance. This allows testing read/write operations on the promoted instance. After testing, the promoted instance can be deleted or kept.

Rolling back a promoted replica is not possible. Performing a failover on the primary would cause downtime. Creating a clone does not test the replication path.

Testing in a separate project is not necessary.

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10

MCQhard

A company runs a critical e-commerce platform on Cloud SQL for PostgreSQL with cross-region read replicas for DR. During a recent disaster drill, they promoted the read replica to a standalone instance. After the drill, they attempted to re-create the replica but found that point-in-time recovery (PITR) was not enabled on the promoted instance. What is the most likely cause?

A.The backup retention policy on the original instance limited the PITR window

B.The cross-region replica connectivity was lost during promotion

C.Automated backups and PITR are not enabled by default on the promoted instance

D.The promoted instance does not support PITR because it was originally a read replica

AnswerC

After promotion, the new primary does not have automated backups or PITR enabled; they must be configured explicitly.

Why this answer

When a Cloud SQL read replica is promoted, it becomes a standalone primary instance. By default, automated backups and PITR are not enabled on the promoted instance. The original instance's configuration (including PITR) is not carried over.

The user must manually enable these settings after promotion.

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11

MCQeasy

An organization needs to define RTO and RPO for their database disaster recovery plan. They have a Cloud SQL for SQL Server instance with HA enabled. What are the typical RTO and RPO for an automatic HA failover?

A.RPO: replication lag (seconds), RTO: minutes

B.RPO: near zero, RTO: under 60 seconds

C.RPO: zero, RTO: zero

D.RPO: minutes, RTO: hours

AnswerB

Cloud SQL HA uses synchronous replication in the same region, providing near-zero RPO and RTO under 60 seconds.

Why this answer

Cloud SQL HA failover is automatic within the same region. It provides RPO near zero (minimal data loss) and RTO typically under 60 seconds.

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12

Multi-Selectmedium

A company is planning disaster recovery for Bigtable. They have two clusters in different regions with replication enabled. They want to automate failover using Cloud DNS. Which THREE components are required for this automation? (Choose 3)

Select 3 answers

A.Bigtable replication routing policy set to any-replica.

B.Cloud Bigtable AppProfile with single-cluster routing.

C.Cloud HTTP(S) health check for the Bigtable cluster endpoints.

D.Cloud Functions to update the DNS record on health check failure.

E.Cloud DNS managed zone with a weighted routing policy.

AnswersC, D, E

Health checks determine primary cluster health.

Why this answer

To automate Bigtable failover, you need a Cloud HTTP(S) health check to monitor the primary cluster, a Cloud DNS routing policy (e.g., weighted round robin) that can be updated, and a mechanism (e.g., Cloud Functions or an external tool) to update the DNS record when the health check fails.

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13

MCQmedium

A company uses Cloud Bigtable with replication across two regions. They want to ensure that read requests are automatically routed to the nearest available cluster with the lowest latency. Which routing policy should be configured?

A.Single-cluster routing

B.Any-replica routing

C.Multi-cluster routing

D.Read-failover routing policy

AnswerC

Multi-cluster routing routes reads to the nearest cluster based on latency and provides automatic failover, meeting the requirement.

Why this answer

Bigtable replication supports two routing policies: single-cluster routing and multi-cluster routing. Multi-cluster routing allows the Bigtable client to route requests to the nearest cluster based on latency, and it automatically fails over to another cluster if the first is unavailable. Any-replica routing is not a valid Bigtable policy.

Read-failover routing is a Cloud DNS concept, not Bigtable. Single-cluster routing forces all requests to a specific cluster.

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14

MCQmedium

A company needs to store petabytes of time-series IoT sensor data and query it with single-digit millisecond latency at millions of reads per second. The data has a simple key-value structure with timestamps. Which Google Cloud database is MOST appropriate?

A.BigQuery

B.Cloud Spanner

C.Firestore

D.Cloud Bigtable

AnswerD

Bigtable is the correct choice: wide-column NoSQL, designed for time-series and IoT workloads, single-digit ms latency, and scales to millions of QPS with additional nodes.

Why this answer

Cloud Bigtable is designed for exactly this use case — petabyte-scale, low-latency (single-digit ms), high-throughput NoSQL storage for time-series, IoT, and financial data. It scales horizontally by adding nodes. BigQuery is optimised for analytics (seconds-to-minutes latency), Cloud SQL is for OLTP (limited to tens of thousands of QPS), and Firestore is for document data with hierarchical structure.

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15

MCQeasy

An organization requires a disaster recovery solution for Cloud SQL with a target RPO of less than 5 minutes and RTO of less than 2 hours. The primary region is us-central1, and the DR region is us-west1. Which approach should they use?

A.Create a cross-region read replica and promote it during disaster

B.Use point-in-time recovery with daily backups and restore into a new instance

C.Configure a scheduled export of the database to Cloud Storage and import in DR region

D.Enable HA configuration in a single region

AnswerA

Cross-region read replicas have minimal replication lag, providing low RPO and RTO within minutes after promotion.

Why this answer

Cross-region read replicas provide an RPO equal to replication lag (typically <5s) and RTO of minutes (manual promotion). This meets the requirements. Cross-region backup restore would have an RPO equal to the last backup age (hours) and RTO of hours.

HA failover is for same-region only. PITR alone does not provide cross-region DR.

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16

Multi-Selectmedium

A company is designing a disaster recovery plan for their Cloud Bigtable instance. They need to ensure that in the event of a regional outage, they can failover to a secondary region with minimal data loss and automatic re-routing of traffic. Which TWO actions should they take? (Choose two.)

Select 2 answers

A.Export Bigtable data to Cloud Storage daily and script the import into a new cluster.

B.Set up Cloud DNS with a health check that updates the routing policy to the secondary cluster on failure.

C.Increase the number of nodes in the primary cluster to handle failover load.

D.Configure Bigtable replication with a secondary cluster in a different region.

E.Use Cloud Spanner instead of Bigtable for built-in multi-region failover.

AnswersB, D

Cloud DNS health check can detect primary failure and automatically update the routing policy to direct traffic to the secondary cluster, achieving automated failover.

Why this answer

To achieve DR with Bigtable, you need to configure replication to a secondary cluster in a different region. Additionally, you need to configure the application's routing to failover to the secondary cluster. Using Cloud DNS with a health check that updates the routing policy can automate traffic re-routing.

Increasing the number of nodes does not provide DR. Exporting to Cloud Storage is for backup, not failover. Using Spanner is a different service.

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17

Multi-Selectmedium

An organization needs to design a disaster recovery plan for Cloud SQL for PostgreSQL with an RPO of 10 seconds and an RTO of 5 minutes. Which TWO solutions meet these requirements? (Choose 2)

Select 2 answers

A.Cloud SQL cross-region read replica with manual promotion.

B.Export the database to Cloud Storage and import in another region.

C.Cloud SQL HA with automatic failover to standby in the same region.

D.Cloud SQL point-in-time recovery from backups.

E.Use Cloud SQL automated backups with cross-region copy.

AnswersA, C

If replication lag is under 10 seconds and manual promotion completes within 5 minutes, this meets the RPO and RTO.

Why this answer

Cloud SQL HA provides near-zero RPO and RTO under 60 seconds within the same region. Cross-region read replicas can achieve RPO of seconds if replication lag is low, and manual promotion takes minutes.

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18

MCQhard

You are designing disaster recovery for a globally distributed application using Cloud Spanner with a multi-region configuration. The application requires an RPO of 0 and an RTO of less than 5 seconds in the event of a full region failure. Which Spanner configuration provides these guarantees?

A.A single-region Spanner instance with a read replica in another region.

B.A multi-region Spanner instance with one read-write region and two read-only regions.

C.A dual-region Spanner instance using default leader placement.

D.A multi-region Spanner instance with two read-write regions and one witness region.

AnswerD

Correct: a multi-region instance with at least two read-write regions can achieve synchronous replication and automatic failover within seconds.

Why this answer

A multi-region configuration with a leader region and at least two voting regions provides synchronous replication and automatic failover. Regional failover occurs within seconds, preserving zero data loss.

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19

Multi-Selectmedium

A company needs to define backup retention policies for Cloud SQL, Spanner, and Bigtable to meet compliance requirements. Which THREE statements about backup retention are correct? (Choose three.)

Select 3 answers

A.Cloud SQL automated backups can be retained for up to 365 days.

B.Cloud SQL automated backups can be retained for up to 730 days.

C.Bigtable managed backups have a maximum retention of 30 days.

D.Bigtable on-demand backups can be retained indefinitely by using Cloud Storage object lifecycle management.

E.Cloud Spanner backup expiration can be set to a maximum of 365 days.

AnswersA, D, E

Cloud SQL allows setting backup retention up to 365 days for automated backups.

Why this answer

Cloud SQL automated backups can be retained for up to 365 days. Spanner backup expiration is maximum 365 days. Bigtable on-demand backups are stored in Cloud Storage and can be retained indefinitely using lifecycle policies.

The other options are incorrect: Cloud SQL maximum is 365 days, Spanner maximum is 365 days, Bigtable backups are not limited to 30 days.

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20

MCQmedium

A company runs an e-commerce platform on Cloud SQL for MySQL. They need to comply with a policy that requires database backups to be retained for 365 days. They also need to restore to any point within the last 30 days. How should they configure their backup settings?

A.Use export to Cloud Storage daily and store exports for 365 days

B.Enable automated backups with retention set to 365 days and enable binary logging for PITR

C.Enable automated backups with retention set to 365 days and set transaction log retention to 365 days

D.Enable automated backups with retention set to 30 days and create on-demand backups daily to cover the 365-day retention

AnswerD

On-demand backups (snapshots) can be retained indefinitely. Automated backups for PITR can be set to 30 days to meet PITR requirement, while on-demand backups meet long-term retention.

Why this answer

Cloud SQL supports automated backups and point-in-time recovery (PITR) using binary logs. The maximum automated backup count is 365, and you can set the transaction log retention for PITR up to 35 days. For 365-day retention, you need to use on-demand backups (snapshots) which can be retained indefinitely.

For PITR within 30 days, enable automated backups and binary logging with a log retention of 30 days.

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21

Multi-Selectmedium

A company uses Cloud Bigtable with two clusters in different regions for disaster recovery. They need to ensure that if the primary cluster becomes unavailable, read traffic is automatically redirected to the secondary cluster with minimal manual intervention. Which three actions should they take? (Choose THREE)

Select 3 answers

A.Enable multi-cluster replication between the clusters

B.Set up Cloud DNS with a health check to detect cluster health and update DNS records accordingly

C.Configure the Bigtable routing policy to 'any-replica' or 'read-failover'

D.Add read-only replicas to the secondary cluster

E.Configure a write failback policy to switch write clusters

AnswersA, B, C

Multi-cluster replication is necessary to keep data in sync across regions.

Why this answer

To achieve automatic failover for Bigtable reads, you need: (1) multi-cluster replication enabled, (2) a routing policy that supports failover (read-failover or any-replica with health checking), and (3) an external health check mechanism (like Cloud DNS health checks) to redirect client traffic if the primary cluster is unhealthy. Option D (write failback) is not relevant for reads. Option E (read-only replicas) is not applicable as Bigtable doesn't have that concept.

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22

MCQhard

A company runs a critical application on Cloud SQL for MySQL with an HA configuration. They want to test their disaster recovery plan without affecting production. They need to validate that a cross-region read replica can be promoted successfully in the event of a regional outage. Which approach should they take?

A.Promote the cross-region read replica to a standalone instance, then re-create the replica after testing

B.Use point-in-time recovery to restore the primary to a new instance in the secondary region

C.Create a new read replica in the secondary region and promote that

D.Create a clone of the cross-region read replica and promote the clone

AnswerD

Cloning creates an independent copy that can be promoted without affecting the original replica or primary.

Why this answer

To test DR without affecting production, you can promote a cross-region read replica to a standalone instance for testing. However, promoting a read replica stops replication and makes it a writable instance. To avoid impacting production, you should create a clone of the cross-region read replica and promote the clone.

Alternatively, you can create a snapshot of the replica and restore to a new instance. The safest way is to create a clone from the replica and promote the clone.

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23

MCQmedium

A company uses Cloud Bigtable for real-time analytics. They need to implement disaster recovery across regions with a recovery point objective (RPO) of no more than 5 minutes and recovery time objective (RTO) under 10 minutes. Which approach should they take?

A.Configure Bigtable replication with a secondary cluster in a different region and use Cloud DNS health checks to update routing policy on failover.

B.Perform daily exports of Bigtable data to Cloud Storage and import into a new cluster in case of failure.

C.Migrate the workload to Cloud Spanner multi-region for built-in disaster recovery.

D.Use Cloud Scheduler to trigger a script that takes a Bigtable snapshot every hour.

AnswerA

Bigtable replication provides asynchronous replication across regions (RPO seconds to minutes). Cloud DNS with health checks can automate routing to the secondary cluster, achieving RTO <10 minutes.

Why this answer

Bigtable replication allows creating secondary clusters in different regions. Asynchronous replication has typical lag of a few seconds to minutes, meeting RPO of 5 minutes. For failover, the application's routing policy must be updated to point to the secondary cluster.

Cloud DNS health checks can detect primary failure and automatically update routing policy. Backups have RPO equal to backup interval (hours) and RTO of hours. Exporting to Cloud Storage is manual and slow.

Using Cloud Spanner is a different service.

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24

MCQeasy

What is the maximum backup retention period for Cloud Spanner backups?

A.365 days

B.730 days

C.90 days

D.30 days

AnswerA

Correct: maximum retention is 365 days.

Why this answer

Cloud Spanner allows backups to be retained for up to 365 days.

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25

MCQhard

A gaming company uses Cloud Bigtable for player state data with two clusters in different regions (us-central1 and us-west1) for disaster recovery. They need to ensure that read traffic automatically fails over to the secondary cluster if the primary cluster becomes unhealthy. They currently have a weighted DNS routing policy. Which additional configuration is required?

A.Use a Cloud DNS health check that updates a routing policy in Bigtable

B.Set the Bigtable cluster routing policy to 'read-failover'

C.Enable multi-cluster routing by setting 'any-replica' policy

D.Configure a Cloud Load Balancer with a backend service pointing to the Bigtable clusters

AnswerB

The read-failover routing policy ensures that if the primary cluster is unhealthy, reads are automatically directed to the next healthy cluster.

Why this answer

Cloud Bigtable with multi-cluster replication can use routing policies. The 'read-failover' routing policy directs reads to the nearest healthy cluster. To handle unhealthy clusters, you can use Cloud DNS with a health check that updates the routing policy, but the simplest approach is to configure the Bigtable routing policy to 'read-failover'.

This policy automatically shifts reads away from unhealthy clusters.

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26

MCQmedium

A healthcare company uses Cloud Bigtable for patient event logs. They need to ensure data is available in another region in case of a regional outage. They set up a second cluster in a different region with replication. What is the RPO characteristic of Bigtable replication, and what routing policy ensures reads continue if the primary cluster fails?

A.RPO is asynchronous (replication lag); use 'any-replica' routing policy

B.RPO is near zero (synchronous replication); use 'multi-cluster' routing

C.RPO is up to 1 hour; use 'single-cluster' routing

D.RPO is synchronous (near zero); use 'read-failover' routing policy

AnswerA

Bigtable replication is asynchronous, so RPO is the lag. The 'any-replica' routing policy distributes reads across all clusters, providing automatic failover if one cluster is down.

Why this answer

Bigtable replication is asynchronous, meaning the RPO is the replication lag (typically seconds to minutes). For automatic failover in reads, you can use the 'single-cluster routing' with a fallback or 'cluster-group routing' (any-replica) that sends requests to any available cluster. However, the question asks about routing policy to ensure reads continue if primary fails.

The 'any-replica' routing policy sends read/write requests to the nearest available cluster, providing automatic failover. 'Read-failover' is not a standard term; there is a 'single-cluster routing' with 'allow writes from any cluster' but that's for writes.

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27

MCQhard

A company uses Cloud Spanner multi-region with the nam-eur-asia1 configuration. They experience a regional outage that affects two of the three regions. What is the expected behavior regarding read and write availability?

A.Reads are available but writes are unavailable until the leader region recovers.

B.The entire instance becomes unavailable due to loss of quorum.

C.The instance becomes read-only until at least two regions recover.

D.Read and write availability are unaffected because Spanner automatically fails over to remaining regions.

AnswerD

Spanner multi-region with nam-eur-asia1 (3 regions, multiple zones each) can tolerate loss of two regions. The remaining region(s) continue to serve reads and writes, with a brief failover if leader region is lost.

Why this answer

Spanner multi-region with 5+ regions (like nam-eur-asia1 which has 3 regions with multiple zones each) can tolerate the loss of up to two regions while maintaining read/write availability. The remaining region(s) will continue to serve reads and writes. However, if the leader region is lost, a new leader is elected from remaining regions, which may cause a brief write unavailability (RTO <1 min).

Spanner guarantees 99.999% availability for multi-region instances.

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28

MCQmedium

A company needs to store petabytes of time-series IoT sensor data and query it with single-digit millisecond latency at millions of reads per second. The data has a simple key-value structure with timestamps. Which Google Cloud database is MOST appropriate?

A.Firestore

B.Cloud Spanner

C.Cloud Bigtable

D.BigQuery

AnswerC

Bigtable is the correct choice: wide-column NoSQL, designed for time-series and IoT workloads, single-digit ms latency, and scales to millions of QPS with additional nodes.

Why this answer

Cloud Bigtable is designed for exactly this use case — petabyte-scale, low-latency (single-digit ms), high-throughput NoSQL storage for time-series, IoT, and financial data. It scales horizontally by adding nodes. BigQuery is optimised for analytics (seconds-to-minutes latency), Cloud SQL is for OLTP (limited to tens of thousands of QPS), and Firestore is for document data with hierarchical structure.

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29

Multi-Selecthard

A company runs a critical application on Cloud SQL for SQL Server and wants to implement a disaster recovery plan with RPO < 5 minutes and RTO < 1 hour. They are willing to accept some manual steps during failover. Which two strategies should they combine? (Choose TWO)

Select 2 answers

A.Use Cloud Backup for DR (CBR) to create backup plans

B.Schedule on-demand backups every 5 minutes and restore to another region

C.Use Cloud SQL point-in-time recovery (PITR) to a cross-region instance

D.Configure a cross-region read replica

E.Use a Cloud SQL HA instance with automatic failover

AnswersC, D

PITR can restore to a specific point in time within the retention period, complementing the replica strategy for scenarios where the primary becomes corrupt.

Why this answer

For Cloud SQL, cross-region read replicas provide asynchronous replication with RPO typically under 5 minutes if monitored. Manual promotion of the replica can achieve RTO under 1 hour. Additionally, point-in-time recovery (PITR) using binary logs can provide RPO within 5 minutes by recovering to a specific time, but restoring from a backup takes longer.

However, combining a cross-region replica (for faster failover) with PITR (for additional recovery options) gives flexibility. Option A (HA instance) is same-region only. Option C (on-demand backups) has higher RPO.

Option D (CBR) is for Spanner, not Cloud SQL. The best combination is cross-region replica for failover and PITR for point-in-time recovery.

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30

Multi-Selecteasy

A company uses Cloud Spanner and needs to design a backup strategy that meets a 24-hour RPO and 4-hour RTO. Which TWO statements are correct for achieving these goals? (Choose 2)

Select 2 answers

A.Use point-in-time recovery to restore to any point within the last 24 hours.

B.Export the database to Avro files in Cloud Storage.

C.Create a cross-region read replica for failover.

D.Schedule a daily backup of the Spanner database.

E.Restore the backup to a new Spanner instance in the same region.

AnswersD, E

Daily backup gives RPO up to 24 hours.

Why this answer

Spanner backups can be created on-demand or scheduled. The backup restore typically completes in hours depending on size, and can meet 4-hour RTO. Scheduling daily backups meets 24-hour RPO.

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31

MCQmedium

A company has a Cloud SQL for PostgreSQL instance with cross-region read replicas for disaster recovery. They want to test the failover process without affecting the primary instance. What is the recommended approach?

A.Create a clone of the primary instance and promote the clone to simulate failover.

B.Promote the cross-region read replica to a standalone instance in a separate project for testing.

C.Trigger a failover using the gcloud sql instances failover command on the primary instance.

D.Stop the primary instance and observe how the application behaves.

AnswerB

Promoting a read replica creates a new standalone instance without affecting the primary. Testing in a separate project avoids interference. This is a non-destructive way to validate failover.

Why this answer

Cloud SQL cross-region read replicas can be promoted to a standalone instance. This promotion is a manual operation that creates a new primary instance. To test failover non-destructively, you can promote a read replica to a standalone instance in a different project or region.

You can then test connectivity and read/write operations. After testing, you can either keep the promoted instance or delete it. You cannot failover and then revert the replica; promotion is irreversible.

The promotion does not affect the original primary instance.

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32

MCQeasy

A company uses Cloud Spanner and needs to retain backups for 365 days for compliance. What is the maximum backup expiration period that can be set for a Spanner backup?

A.30 days

B.365 days

C.Unlimited

D.90 days

AnswerB

The max backup expiration for Spanner is 365 days.

Why this answer

Spanner backups can have an expiration time set to a maximum of 365 days from the creation time. After that, the backup is automatically deleted.

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33

MCQmedium

A company uses Cloud Bigtable for a real-time analytics pipeline. They have configured replication with a primary cluster in us-central1 and a secondary cluster in us-west1. They want to minimize data loss during a failover to the secondary cluster. What is the best approach to achieve the lowest possible RPO?

A.Use single-cluster routing with failover priority set to the secondary cluster.

B.Use any-replica routing and let Cloud Bigtable automatically direct reads and writes to the healthiest cluster.

C.Use single-cluster routing and regularly back up the Bigtable data.

D.Use multi-cluster routing with read-failover enabled and direct all writes to the primary cluster.

AnswerD

This configuration ensures writes go to primary (minimizing replication lag) and reads automatically fail over to secondary when primary is unhealthy, minimizing data loss.

Why this answer

Bigtable replication is asynchronous, so RPO is determined by replication lag. To minimize data loss, you should route writes to the primary cluster and use read-failover routing to consume from the secondary only when primary is unhealthy. During failover, switch writes to secondary manually.

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34

MCQmedium

A company uses AlloyDB for PostgreSQL for their operational database. They want to ensure automatic failover with the shortest possible RTO. Which configuration should they use?

A.Deploy a single-zone AlloyDB cluster with a read pool

B.Configure a cross-region read replica and set up automated promotion scripts

C.Use an AlloyDB basic (single-node) instance

D.Deploy a multi-zone AlloyDB cluster with automatic failover enabled

AnswerD

AlloyDB's multi-zone cluster provides automatic failover to a standby in another zone, with RTO typically under 30 seconds.

Why this answer

AlloyDB provides automatic failover with RTO under 60 seconds. Cross-zone failover in a multi-zone cluster provides the best availability within a region. Cross-region replication is not automatic and requires manual promotion.

Basic instances offer no HA. Read pool failover is not automatic.

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35

MCQhard

A company uses Cloud Bigtable for their analytics pipeline. They set up replication with a primary cluster in us-central1 and a secondary in us-west1. They notice that during normal operation, queries always hit the primary cluster even if the secondary is closer. What should they change to route queries to the nearest cluster automatically?

A.Change the app profile routing policy to any-replica

B.Implement client-side logic to choose which cluster to query

C.Modify the primary cluster to be in us-west1

D.Update the app profile to use read-failover routing

AnswerA

any-replica routing sends queries to the closest cluster, reducing latency.

Why this answer

The default routing policy for Bigtable replication is single-cluster (to the primary). To route to the nearest healthy cluster, they need to enable the any-replica routing policy in their Bigtable app profile. read-failover is for DR failover, not for normal operations. Changing the primary cluster does not solve the routing issue.

Client-side logic is an option but not a built-in solution.

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36

MCQmedium

A financial services company runs a global trading application on Cloud Spanner. They need the highest availability with 99.999% SLA and automatic failover with zero data loss. Which Spanner configuration should they choose?

A.Multi-region configuration nam-eur-asia1 (US, Europe, Asia)

B.Regional configuration in us-central1 with read replicas

C.Multi-region configuration nam6 (US, limited to North America)

D.Regional configuration with a cross-region standby using backup/restore

AnswerA

This three-continent configuration provides 99.999% SLA, automatic failover with RPO=0, and is designed for global availability.

Why this answer

Multi-region configurations provide 99.999% SLA. Among the options, nam-eur-asia1 spans three continents with read-write replicas in each continent, offering automatic failover with zero data loss (RPO=0). Regional configuration offers 99.99% SLA.

Multi-region with only read-only replicas in some regions does not achieve the same failover capability.

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37

MCQeasy

A company wants to implement a disaster recovery plan for their AlloyDB database. They need automatic failover with minimal data loss and RTO under 30 seconds. Which configuration should they use?

A.Configure a cross-region read replica and promote it manually during a disaster.

B.Enable high availability (HA) on the AlloyDB cluster, which provisions a standby in a different zone.

C.Deploy AlloyDB in a single zone without HA.

D.Use AlloyDB with multiple read pools and a custom failover script.

AnswerB

AlloyDB HA provides automatic failover within 30 seconds and minimal data loss.

Why this answer

AlloyDB provides automatic failover within 30 seconds when you enable high availability (primary + standby). This is zone-redundant within the same region.

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38

MCQhard

A social media company uses Cloud Spanner with a multi-region configuration. During a regional outage, automatic failover occurred, but some transactions that were in-flight at the time of failure were lost. What is the most likely reason for this data loss?

A.The database had schema changes that were not replicated to standby replicas

B.The transaction isolation level was set to read committed instead of serializable

C.The application did not retry failed transactions after the failover

D.The multi-region configuration included read-only replicas in some regions, causing loss of recent writes

AnswerD

Only read-write replicas can become the new leader. If a region has only read-only replicas, committed transactions from the old leader may not be fully replicated before failover, resulting in data loss.

Why this answer

In a multi-region Spanner configuration, the leader region handles writes. If a transaction was committed but not yet replicated to other regions before the leader region failed, it could be lost if the new leader region does not have that data. However, Spanner's multi-region configurations are designed for RPO=0 (no data loss) when using read-write replicas.

If read-only replicas are used in some regions, data loss can occur because those replicas do not participate in the voting. The most common cause of data loss in Spanner multi-region is a misconfiguration where not all regions have read-write replicas.

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39

Multi-Selecteasy

A company uses Cloud SQL for MySQL and wants to define backup retention policies for compliance. Which TWO statements about Cloud SQL backup retention are correct? (Choose 2)

Select 2 answers

A.The maximum retention period for automated backups is 365 days.

B.Point-in-time recovery logs are retained for a maximum of 7 days.

C.Automated backups are retained for a minimum of 7 days.

D.The maximum number of automated backups retained is 365.

E.Backups are always stored in the same region as the database.

AnswersA, D

Correct: you can set retention days up to 365.

Why this answer

Cloud SQL supports up to 365 automated backups and allows setting retention days up to 365. Point-in-time recovery also has a configurable retention.

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40

Multi-Selecthard

A company uses Cloud SQL for PostgreSQL with cross-region read replicas for DR. They want to automate the failover process to reduce RTO. Which THREE components should they include in their automation? (Choose 3 correct answers.)

Select 2 answers

A.A configuration to automatically create a new read replica after promotion

B.A script to promote the cross-region read replica to a primary instance using gcloud sql instances promote-replica

C.A script to create a new read replica in the DR region

D.A health check mechanism to detect primary region failure

E.A Cloud DNS managed zone with a weighted routing policy to split traffic evenly across regions

AnswersB, D

Promotion is the key step to make the replica the new primary.

Why this answer

To automate cross-region failover, you need to detect the primary failure (health check), promote the replica (gcloud command), and update DNS to point to the new primary. Option A is not needed because the replica is already set up. Option D is not required as the replica is already created.

Option E would increase complexity unnecessarily.

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41

MCQmedium

An organization uses Cloud SQL for MySQL and needs to perform disaster recovery testing by failing over to a cross-region read replica without impacting the primary instance. They want to validate the promotion process and measure the actual RTO. Which approach should be used?

A.Create a clone of the primary instance in the target region and test failover

B.Use Cloud SQL’s switchover feature for HA instances

C.Promote a cross-region read replica in an isolated project or non-production environment

D.Run a gcloud command to promote the existing read replica in the production project

AnswerC

Promoting a replica that is not serving production traffic allows safe DR testing while measuring RPO (replication lag) and RTO (promotion time).

Why this answer

The safest way to test DR without impacting the primary is to promote a cross-region read replica in a non-production environment or an isolated project. The promotion is manual and can be tested by simulating a failover scenario. Alternatively, you can clone the replica to a separate instance for testing, but the most direct test is promoting a replica that is not serving production traffic.

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42

Multi-Selecthard

A company runs a critical application on AlloyDB in a single zone. They want to improve resiliency with an RTO under 30 seconds and RPO near zero. Which THREE steps should they take? (Choose 3)

Select 3 answers

A.Increase the number of CPU cores in the primary instance.

B.Configure application connection retry logic to handle failover interruptions.

C.Configure a cross-region read replica in a different region.

D.Perform regular failover drills to ensure RTO targets are met.

E.Enable high availability (HA) on the AlloyDB cluster.

AnswersB, D, E

Retry logic ensures application reconnects to the new primary after failover.

Why this answer

To achieve RTO<30s and RPO near zero, you need to enable AlloyDB HA (primary + standby in different zone), ensure the application retries connections during failover, and regularly test failover to validate RTO.

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43

Multi-Selectmedium

A company is evaluating disaster recovery options for their production Bigtable instance. They need asynchronous replication with manual failover and the ability to route reads to the secondary cluster only when the primary is unhealthy. Which TWO settings should they configure? (Choose 2 correct answers.)

Select 2 answers

A.Use Cloud DNS health checks to update DNS records to point to the secondary cluster

B.Enable automatic failover by setting the replication to synchronous mode

C.Configure a multi-cluster routing policy with a single-cluster fallback

D.Create an app profile with read-failover routing policy

E.Create an app profile with any-replica routing policy

AnswersA, D

During manual failover, updating DNS records to point to the secondary is necessary, and health checks can automate this.

Why this answer

Bigtable replication uses app profiles. To achieve manual failover with routing to secondary only when primary is unhealthy, they should configure a read-failover routing policy on an app profile. They should not use any-replica because that would route reads to the secondary during normal operation.

Option A is automatic, not manual. Option D is not a valid routing policy. Option E would not meet the requirement of using secondary only when primary unhealthy.

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44

Multi-Selecthard

A company uses Cloud Spanner with a single-region configuration in us-central1. They need to improve disaster recovery to meet an RPO of zero and an RTO of less than 5 seconds across regions. Which three actions should they take? (Choose three.)

Select 3 answers

A.Add a cross-region read replica to the existing single-region instance

B.Use backup/restore to migrate data from the single-region instance to the new multi-region instance

C.Enable point-in-time recovery (PITR) with 7-day retention

D.Update application connection strings to point to the multi-region instance

E.Create a new multi-region Spanner instance with a two-region configuration (e.g., nam6)

AnswersB, D, E

Backup/restore is a reliable way to move data between instances.

Why this answer

To achieve RPO=0 and RTO<5s across regions, you need a multi-region Spanner configuration with synchronous replication. You cannot achieve cross-region RPO=0 with a single-region instance. Therefore, you must migrate to a multi-region configuration.

The steps include: 1) Create a new multi-region instance (e.g., nam6) with the desired config, 2) Migrate data from the single-region instance to the multi-region instance (e.g., using backup/restore or Dataflow), 3) Update application connection strings to point to the new instance. Optionally, you can perform a rolling migration to minimize downtime. Using cross-region read replicas is not possible for Spanner (Spanner does not have read replicas in the same sense; it uses replica types within an instance).

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45

MCQhard

A company uses Cloud Spanner in a multi-region configuration with the leader region in us-central1. They want to improve write latency for users in Europe. The application's writes are latency-sensitive and must be strongly consistent. Which action should the engineer take?

A.Add more read-only replicas in the European region.

B.Use a regional Spanner instance in Europe and replicate data asynchronously to the multi-region instance.

C.Migrate the workload to Cloud Bigtable with replication.

D.Change the leader region to a European region, such as europe-west1.

AnswerD

Setting the leader region to Europe ensures writes are committed in Europe, reducing write latency for European users while maintaining strong consistency.

Why this answer

In Spanner multi-region, the leader region determines where writes are committed. To reduce write latency for European users, set the leader region to a European region (e.g., europe-west1). All writes will be committed in that region, reducing round-trip time for European clients.

This does not affect consistency; Spanner still provides strong consistency globally. Adding more read replicas in Europe does not affect write latency. Moving the application to Cloud SQL or Bigtable does not provide the same global strong consistency or may not meet requirements.

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46

MCQeasy

Which GCP database service automatically replicates data across multiple zones within a region and provides an SLA of 99.999% for multi-region configurations?

A.Firestore

B.Cloud SQL

C.Cloud Bigtable

D.Cloud Spanner

AnswerD

Spanner automatically replicates data across zones and regions (multi-region) and provides 99.999% SLA for multi-region configurations.

Why this answer

Cloud Spanner is a globally distributed, strongly consistent relational database that automatically replicates data across zones. It offers 99.999% SLA for multi-region instances. Cloud SQL HA replicates across zones but has a lower SLA.

Bigtable replicates asynchronously across regions but does not guarantee strong consistency. Firestore offers multi-region replication but not 99.999% SLA.

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47

MCQmedium

A company uses Cloud Spanner and needs to back up a large database (several TB) for compliance reasons. They want to retain the backup for 400 days. What is the optimal approach to meet this requirement?

A.Create a backup with 365-day retention, and before it expires, create another backup to extend coverage

B.Create a backup and set the expiration time to 400 days using the gcloud command

C.Use continuous PITR to retain transaction logs for 400 days

D.Export the database to Cloud Storage using Dataflow or an export job, which can be retained indefinitely

AnswerD

Exporting to Cloud Storage bypasses the 365-day limit; you can retain exports as long as needed.

Why this answer

Cloud Spanner allows creating backups that can be retained for up to 365 days. For a retention of 400 days, you cannot use a single backup. Instead, you can create a backup and then take another backup before the first expires, or export data to Cloud Storage (e.g., using Dataflow) which has no expiration limit.

Using the console, you are limited to 365 days; to exceed that, you must use long-term retention outside of Spanner backups.

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48

MCQmedium

A company runs a Cloud SQL for PostgreSQL instance with a cross-region read replica in a different region for disaster recovery. The primary region experiences a complete outage. What is the expected RPO and RTO for promoting the read replica to become the new primary?

A.RPO: up to 1 hour; RTO: up to 24 hours

B.RPO: near zero (loss of last few transactions); RTO: under 60 seconds

C.RPO: zero; RTO: less than 1 minute

D.RPO: equals the replication lag (seconds to minutes); RTO: minutes (manual promotion)

AnswerD

Cross-region read replicas replicate asynchronously, so RPO is the replication lag. Manual promotion takes minutes to complete and reconfigure.

Why this answer

Promoting a cross-region read replica involves manual intervention. The RPO equals the replication lag (which can be seconds to minutes depending on network and workload), not zero. The RTO is measured in minutes because you must verify the replica, promote it, and reconfigure applications.

Cloud SQL HA failover (same region) achieves RPO near zero and RTO under 60 seconds, but cross-region replication is asynchronous.

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49

MCQeasy

A financial application requires zero data loss (RPO=0) and automatic failover within 60 seconds in the event of a zone failure. The database must support ACID transactions. Which Google Cloud service meets these requirements?

A.Cloud SQL with HA configuration

B.Cloud SQL cross-region read replica

C.Cloud SQL single-zone instance with automatic backups

D.Cloud Bigtable multi-cluster replication

AnswerA

Cloud SQL HA provides automatic zone failover with synchronous replication, offering RPO ~0 and RTO < 60 seconds.

Why this answer

Cloud SQL with HA configuration uses synchronous replication to a standby instance in a different zone. If the primary zone fails, Cloud SQL automatically fails over to the standby. Because replication is synchronous, RPO is effectively zero.

Automatic failover typically completes within 60 seconds.

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50

MCQhard

A global e-commerce platform uses Cloud Spanner in multi-region configuration. The application writes a significant portion of traffic from Europe and requires the lowest read latency in that region. Which configuration step should be taken to minimise read latency in Europe while maintaining write availability?

A.Configure a separate Spanner instance for European traffic and split the database.

B.Add more read-write replicas in the European region.

C.Use a regional Spanner instance in Europe coupled with a copy of the data in Bigtable.

D.Set the leader region to Europe (e.g., eur3).

AnswerD

Setting the leader region to Europe ensures that writes are committed in Europe, which reduces write latency for European traffic. Read-only replicas in other regions can serve reads with low latency without affecting write availability.

Why this answer

In Spanner multi-region, the leader region determines where writes are committed. Setting the leader region to Europe ensures that writes are committed there, which reduces write latency for European traffic. Read-only replicas in other regions can serve reads with low latency without affecting write availability.

Adding more read replicas in Europe would not reduce latency if the leader region is elsewhere. The number of read-write replicas does not directly reduce read latency. Splitting the database would not help for a single database.

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51

Multi-Selectmedium

A company is using Cloud Spanner and wants to perform disaster recovery testing. They need to validate that their backup and restore process works without impacting production. Which TWO actions should they take? (Choose 2 correct answers.)

Select 2 answers

A.Restore a backup to a new database in the same instance using a different database ID

B.Export the database to Cloud Storage and import it into a new instance

C.Perform a failover to a read replica and then fail back

D.Create a backup of the production database and restore it to a new Spanner instance in a test project

E.Directly restore a backup to the production database to test recovery time

AnswersA, D

This tests the restore process without overwriting the production database.

Why this answer

Restoring a backup to a new instance in a separate project is non-destructive and tests the restore process. Using a different database ID in the same instance also tests restore without overriding production. Option C is destructive (deletes production).

Option D is not about testing. Option E is not a built-in feature for Spanner.

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52

Multi-Selectmedium

A company is designing a disaster recovery strategy for a Cloud SQL for PostgreSQL instance. They require an RPO of less than 5 minutes and an RTO of less than 2 minutes in the event of a regional outage. Which three components should they include in their solution? (Choose three.)

Select 3 answers

A.Cross-region read replica

B.Global external HTTP(S) load balancer with backend health checks

C.Automated promotion script (e.g., using Cloud Functions)

D.Point-in-time recovery enabled with 7-day retention

E.Automated backup with 5-minute frequency

AnswersA, B, C

A read replica in another region provides asynchronous replication, achieving RPO of seconds to minutes.

Why this answer

To achieve RPO <5 minutes and RTO <2 minutes across regions, you need a solution that can recover quickly with minimal data loss. Cloud SQL cross-region read replicas replicate asynchronously, so RPO is the replication lag (which can be <5 minutes if the network is fast). Promoting a read replica manually takes minutes, but you can automate the promotion using Cloud Functions or scripts to reduce RTO.

Alternatively, you could use a standby instance in another region with synchronous replication (but Cloud SQL does not support that). The best approach is to use a cross-region read replica with automated promotion (e.g., via Cloud Functions triggered by a health check). Additionally, you need to update application connection strings to point to the new primary.

Using a load balancer with health checks can also help route traffic. The three correct components are: cross-region read replica, automated promotion script, and a global load balancer to redirect traffic.

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53

MCQmedium

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?

A.Use Cloud SQL export to Cloud Storage and store the export for 400 days using object lifecycle management.

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

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

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

AnswerA

Export to Cloud Storage creates a durable backup that can be retained indefinitely via object lifecycle rules, meeting the 400-day requirement.

Why this answer

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.

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54

MCQeasy

A company runs a critical application on Cloud SQL for PostgreSQL with a 5-minute RPO and 30-minute RTO. They have a cross-region read replica for disaster recovery. During a planned failover test, what is the expected RPO and RTO when promoting the read replica?

A.RPO = 0, RTO = less than 1 minute

B.RPO = replication lag, RTO = minutes

C.RPO = 0, RTO = minutes

D.RPO = backup age, RTO = hours

AnswerB

Correct: cross-region read replicas are asynchronous, so promotion results in loss of unsynchronized data (RPO = lag) and takes minutes to promote (RTO).

Why this answer

Cross-region read replica promotion has an RPO equal to the replication lag (data not yet replicated) and an RTO of minutes (time to promote and make writable).

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55

MCQeasy

A company needs to store petabytes of time-series IoT sensor data and query it with single-digit millisecond latency at millions of reads per second. The data has a simple key-value structure with timestamps. Which Google Cloud database is MOST appropriate?

A.Cloud Spanner

B.BigQuery

C.Firestore

D.Cloud Bigtable

AnswerD

Bigtable is the correct choice: wide-column NoSQL, designed for time-series and IoT workloads, single-digit ms latency, and scales to millions of QPS with additional nodes.

Why this answer

Cloud Bigtable is designed for petabyte-scale, low-latency (single-digit ms), high-throughput NoSQL storage for time-series, IoT, and financial data. It scales horizontally by adding nodes. BigQuery is optimised for analytics (seconds-to-minutes latency), Cloud SQL is for OLTP (limited to tens of thousands of QPS), and Firestore is for document data with hierarchical structure.

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56

MCQmedium

A company is designing a global user database that must support strong consistency and horizontal scaling with automatic failover. They have a 99.999% uptime requirement and need to serve writes from a single primary region with reads from multiple regions. Which Google Cloud database and configuration should they use?

A.Cloud Spanner multi-region configuration with a leader region and read-write and read-only replicas

B.Cloud Firestore in multi-region mode

C.Cloud Bigtable with replication and any-replica routing

D.Cloud SQL for PostgreSQL with cross-region read replicas and auto-failover

AnswerA

Spanner multi-region provides strong consistency, automatic failover, 99.999% SLA, and the ability to have read-write replicas in the leader region and read-only replicas elsewhere.

Why this answer

Cloud Spanner multi-region with read-write replicas in one region (leader) and read-only replicas in others provides strong consistency, global reads, and automatic failover. Bigtable is eventually consistent. Cloud SQL cannot span multiple regions natively.

Firestore does not provide 99.999% SLA.

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57

MCQmedium

A company has a Cloud SQL for MySQL instance with point-in-time recovery (PITR) enabled. They need to restore the database to a specific time exactly 2 hours ago to recover from an accidental data deletion. What is the minimum requirement for this operation?

A.The instance must have a backup window configured within the last 2 hours

B.The instance must have at least one automatic backup taken after the desired restore time

C.Binary logging must be enabled, and the transaction log retention period must cover the desired restore time

D.The instance must be stopped before initiating the restore

AnswerC

PITR requires binary logging enabled and a transaction log retention period that includes the restore time (default 7 days).

Why this answer

PITR in Cloud SQL relies on binary log (binlog) backups. To restore to a specific time, you need to have binary logging enabled and transaction log retention set appropriately. The binlog retention period determines how far back you can perform PITR.

The default is 7 days, but you can configure it. The backup window and number of automatic backups are not directly related to PITR granularity.

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58

MCQmedium

A company uses AlloyDB for an e-commerce platform. They want to achieve the highest availability within a single region. What configuration should they use, and what is the expected failover RTO?

A.Use a primary instance with a standby in the same zone; RTO less than 10 seconds

B.Use a primary instance with multiple read pools; RTO less than 5 seconds

C.Use a primary instance with a cross-region read replica; RTO less than 1 minute

D.Use a primary instance with a standby in a different zone in the same region; RTO less than 30 seconds

AnswerD

AlloyDB HA uses a primary and standby in different zones within the same region. Automatic failover completes in under 30 seconds.

Why this answer

AlloyDB offers an HA configuration with a primary instance and a standby (read pool) in different zones within the same region. Automatic failover occurs in less than 30 seconds. Cross-zone failover is automatic.

There is no cross-region HA in AlloyDB (you can use cross-region replicas but that requires manual promotion).

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59

MCQmedium

A media company uses Cloud Bigtable to serve user recommendations with low latency. They want to implement disaster recovery with a secondary cluster in a different region. They need automatic failover without manual DNS changes. Which routing policy should they configure?

A.Enable any-replica routing policy on the Bigtable cluster

B.Use single-cluster routing with manual DNS failover

C.Implement application-managed routing with a custom health check

D.Configure read-failover routing policy and use Cloud DNS health checks

AnswerD

read-failover with health checks enables automatic failover to the secondary cluster without manual DNS updates, meeting the requirement.

Why this answer

The read-failover policy uses health checks to automatically route traffic to the secondary cluster if the primary becomes unhealthy. Any-replica sends requests to the closest cluster regardless of health. Manual DNS changes would be required for any-replica after a failure.

Application-managed routing is not a built-in Bigtable feature.

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60

MCQeasy

A company runs a critical application on AlloyDB with a primary instance and a read pool. They want to achieve the fastest possible automatic failover during a zone outage, with minimal data loss. What is the expected RTO and RPO for AlloyDB's automatic failover within the same region?

A.RTO < 5 minutes, RPO ~ 1 second

B.RTO < 60 seconds, RPO ~ 0

C.RTO < 30 seconds, RPO < 1 minute

D.RTO < 30 seconds, RPO ~ 0

AnswerD

AlloyDB high-availability failover occurs in under 30 seconds with zero data loss due to synchronous replication.

Why this answer

AlloyDB provides automatic failover to a standby node within the same region, typically completing in under 30 seconds. Replication is synchronous within the region, so RPO is zero (no data loss).

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61

MCQeasy

A startup is building a mobile app and needs a fully managed database that scales automatically for unpredictable workloads. They expect moderate read/write traffic with occasional spikes. They want minimal operational overhead and do not need global distribution. Which Google Cloud database is MOST appropriate?

A.Cloud SQL for PostgreSQL with HA

B.Cloud Spanner regional

C.Cloud Firestore in native mode

D.Cloud Bigtable

AnswerC

Firestore is serverless, auto-scaling, fully managed, and suitable for mobile backends with moderate traffic.

Why this answer

Cloud Firestore is fully managed, serverless, auto-scales, and ideal for mobile apps with moderate traffic. Cloud SQL requires manual scaling. Bigtable is overkill and complex for this workload.

Spanner is designed for global scale and is more complex than needed.

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62

MCQhard

A company runs an e-commerce platform on Cloud Spanner multi-region (nam6). They experience a regional failure affecting the leader region. After failover, they observe increased write latency. What is the most likely cause?

A.The new leader region is geographically farther from the application instances.

B.The new leader region has fewer replicas.

C.The instance is now running in read-only mode.

D.The failover caused data loss, requiring recovery.

AnswerA

Correct: write latency increases when the leader region is farther from the clients, as all writes must be committed in the leader region.

Why this answer

In a multi-region Spanner configuration, the leader region handles write coordination. After failover, a new leader is elected in a different region, which may be farther from the majority of clients, increasing write latency if clients are not geographically distributed.

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63

MCQmedium

A DevOps engineer wants to test disaster recovery for a Cloud SQL for MySQL instance by simulating a zone failure without impacting production traffic. They need to ensure minimal data loss. Which approach should they take?

A.Take an on-demand backup and restore it to a new Cloud SQL instance

B.Use the gcloud command to perform a point-in-time recovery on the same instance

C.Enable the HA configuration and trigger a failover by stopping the primary instance

D.Promote a cross-region read replica in a test project to validate the failover process

AnswerD

Using a read replica in a test project is non-destructive and simulates the failover process without affecting production.

Why this answer

Non-destructive tests are best done using read replicas. Promoting a read replica in a test environment avoids impacting production. Restoring a backup from Cloud Storage would not test the failover process.

Using HA failover would affect production. Restoring to a new instance from PITR tests recovery but not failover.

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64

MCQmedium

A media streaming company uses Cloud Bigtable to store user session data with a single cluster in us-east1. They want to add disaster recovery capability with an RPO of no more than 5 minutes and an RTO of under 10 minutes. Which action should they take?

A.Use Cloud SQL cross-region read replicas

B.Deploy a new Bigtable instance in another region and set up dataflow pipelines to replicate data

C.Create an on-demand backup and restore to another region

D.Add a second cluster in a different region with replication, and configure a Cloud DNS health check to redirect traffic

AnswerD

Adding a replicated cluster in another region and using a health-check-based DNS routing can achieve RPO < 5 minutes and RTO < 10 minutes.

Why this answer

Bigtable replication allows adding a second cluster in a different region with asynchronous replication. The replication lag can be within seconds, typically under 5 minutes. For RTO under 10 minutes, manual failover via the Cloud Console or CLI is sufficient; automatic failover is not built-in but can be achieved with external orchestration.

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65

MCQmedium

A company uses Cloud SQL for MySQL with a 1-hour RPO and 2-hour RTO. They currently rely on automated daily backups. To improve DR capabilities, they want to reduce RPO to 5 minutes while keeping costs low. Which action should they take?

A.Increase backup frequency to every hour.

B.Create a cross-region read replica.

C.Enable point-in-time recovery (PITR) with a binary log retention of 5 minutes.

D.Deploy Cloud SQL HA with a standby in another zone.

AnswerC

PITR uses binary logs to replay transactions, achieving an RPO of seconds to minutes depending on log retention.

Why this answer

Enabling point-in-time recovery (PITR) on Cloud SQL allows restoring to any point in time within the backup retention period, reducing RPO from 24 hours to seconds (limited to binary log retention).

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66

MCQeasy

An organization needs to store backup copies of a Cloud Spanner database for a minimum of 365 days to comply with regulatory requirements. Which backup option should they use?

A.Create a Spanner backup and set the expiration to 365 days

B.Enable point-in-time recovery (PITR) with a 365-day retention period

C.Export the database to Cloud Storage using the gcloud command and set a lifecycle policy

D.Use Cloud SQL for PostgreSQL with automated backups set to 365 days

AnswerA

Spanner backups support expiration up to 365 days, meeting the regulatory requirement.

Why this answer

Cloud Spanner backups can be configured with expiration up to 365 days (max). Import/export to Cloud Storage is not a managed backup solution and does not support PITR. Bigtable backups are for Bigtable, not Spanner.

Cloud SQL backups are for Cloud SQL.

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67

Multi-Selecthard

A company runs a global application on Cloud Spanner with a multi-region configuration. They need to test their DR procedures without impacting production. Which THREE actions should they perform? (Choose 3)

Select 3 answers

A.Delete the production instance and recreate it from a backup.

B.Simulate a zone failure by modifying IAM permissions to restrict access to replicas in a zone.

C.Create a backup of the production database and restore it to a separate instance for validation.

D.Promote a read replica to a writable instance in a different region.

E.Perform a failover test by initiating a planned regional outage using Spanner's API.

AnswersB, C, E

This allows testing failover behavior without actual outage.

Why this answer

Non-destructive tests include creating a backup and restoring it to a separate instance for validation, simulating a zone failure by restricting replica access, and performing regular failover drills via backup/restore to test RTO.

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68

Multi-Selectmedium

A company uses Cloud Bigtable with replication across two regions. They want to implement a DR plan that minimizes RPO and RTO. Which TWO steps should they take? (Choose 2)

Select 2 answers

A.Configure multi-cluster routing with read-failover.

B.Regularly perform failover drills using Cloud DNS health checks to update routing.

C.Enable automatic failover for writes in the Bigtable cluster configuration.

D.Set the replication routing policy to any-replica.

E.Set the replication routing policy to single-cluster with failover priority.

AnswersA, B

This ensures reads fail over automatically while writes remain in primary, minimizing RPO.

Why this answer

Using multi-cluster routing with read-failover ensures reads automatically switch to the secondary cluster when primary is unhealthy, minimizing RPO by directing writes to primary. Regularly testing failover validates the process and updates runbooks.

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69

MCQmedium

A company uses Cloud Spanner with a multi-region configuration (nam6) for a global user database. They experience a regional outage affecting us-central1, where the leader region is located. What happens to write availability?

A.Writes continue with increased latency because us-central1 is still available for reads

B.The Spanner instance becomes read-only until an operator manually fails over

C.Writes are blocked until the us-central1 region recovers

D.Writes automatically fail over to us-east1 within seconds

AnswerD

Spanner multi-region configurations provide automatic failover to the secondary region with RTO <5 seconds.

Why this answer

In a multi-region Spanner configuration like nam6 (us-central1 and us-east1), if the leader region (us-central1) goes down, Spanner automatically fails over to the other region (us-east1) as the new leader. This failover is automatic and typically completes within 5 seconds (RTO <5 seconds). Write availability is restored once the new leader region is elected.

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70

Multi-Selectmedium

A company is designing a disaster recovery strategy for their Cloud Spanner database. They need an RPO of less than 30 seconds and an RTO of less than 1 minute. Which two configurations would meet these requirements? (Choose TWO)

Select 2 answers

A.Cross-region backup and restore

B.Multi-region configuration with read-write replicas (e.g., nam3)

C.Point-in-time recovery (PITR)

D.Regional instance

E.Multi-region configuration with read-only replicas

AnswersB, D

A multi-region configuration with read-write replicas provides automatic failover with RPO ~15s and RTO < 1min.

Why this answer

Spanner regional instance with HA provides RPO=0 and RTO seconds due to synchronous replication within the region, but it does not protect against region failure. A multi-region configuration (e.g., nam3) provides automatic failover with RPO ~15s and RTO < 1min. So options A and D meet the stated requirements.

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71

MCQhard

A DevOps team is implementing chaos engineering for their Cloud SQL for PostgreSQL database. They want to simulate a zone failure that triggers automatic failover of their HA instance without causing data loss. Which approach should they use?

A.Stop the Cloud SQL instance using gcloud sql instances patch --activation-policy NEVER

B.Use the gcloud sql instances failover command

C.Restrict network access to the primary instance

D.Delete the primary database

AnswerB

The 'gcloud sql instances failover' command triggers a graceful failover to the standby zone, simulating a zone failure without data loss.

Why this answer

Cloud SQL HA instances have automatic zone failover. To simulate a zone failure, you can use the gcloud command to trigger failover manually. This performs a planned failover that switches to the standby zone without data loss, mimicking a zone outage.

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72

MCQhard

A financial services firm runs a multi-region Spanner instance with the nam-eur-asia1 configuration. They need to ensure that if the leader region (us-central1) becomes unavailable, failover to another region occurs automatically within 1 minute. What is the expected RPO and RTO for this scenario?

A.RPO ~ 15 seconds, RTO < 1 minute

B.RPO ~ 0, RTO ~ 15 seconds

C.RPO ~ 1 hour, RTO ~ 5 minutes

D.RPO = 0, RTO < 1 minute

AnswerA

This matches Spanner's documented RPO and RTO for multi-region failover.

Why this answer

Spanner multi-region configurations provide automatic failover with RTO under 1 minute. For the nam-eur-asia1 configuration, it is a multi-region with multiple read-write replicas. The RPO is approximately 15 seconds because Spanner uses quorum-based replication; in the event of a region failure, a small number of recent transactions may be uncommitted.

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73

MCQeasy

A company needs to choose a Google Cloud database for a globally distributed application that requires strong consistency across continents and an SLA of 99.999% for availability. Which database service meets these requirements?

A.Cloud Bigtable

B.Cloud SQL

C.Firestore

D.Cloud Spanner

AnswerD

Spanner provides global strong consistency and a 99.999% SLA for multi-region configurations.

Why this answer

Cloud Spanner is the only Google Cloud database that provides global strong consistency and a 99.999% availability SLA when using a multi-region configuration. Bigtable offers only eventual consistency across regions, Cloud SQL is regional, and Firestore provides strong consistency only within a single region.

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74

MCQhard

A global financial services company requires a multi-region Spanner instance with an RPO of zero and an RTO of less than 5 seconds for a critical transactional workload. The application writes to a single region and reads from multiple regions. Which Spanner configuration should they choose?

A.A single-region configuration with read replicas in multiple zones

B.A two-region multi-region configuration (e.g., nam6)

C.A dual-region configuration with two read-write regions and one read-only region

D.A three-region multi-region configuration (e.g., nam-eur-asia1)

AnswerB

Two-region multi-region configs use synchronous replication across two regions, providing RPO=0 and RTO<5s. Nam6 (us-central1 and us-east1) fits this scenario.

Why this answer

For zero RPO and sub-5-second RTO, a multi-region configuration with synchronous replication is needed. Spanner multi-region configurations like nam6 use synchronous replication across a primary and secondary region (with both read-write replicas). The leader region handles writes, and read-only replicas are for reads.

A two-region multi-region config (e.g., nam6) provides synchronous replication (RPO=0) and automatic failover in <5 seconds. Three-region configs (nam-eur-asia1) have higher write latency due to longer distances.

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75

Multi-Selecthard

A company uses Cloud Spanner in a multi-region configuration. They want to perform a non-destructive disaster recovery drill to validate their ability to recover from a regional failure. Which THREE steps should they include in the drill? (Choose three.)

Select 3 answers

A.Validate that the restored instance has the correct data and schema.

B.Restore a Spanner backup to a new instance in a different region.

C.Update the disaster recovery runbook with any issues found during the drill.

D.Stop the primary Spanner instance to simulate a region failure and observe automatic failover.

E.Promote a cross-region read replica to a new primary instance.

AnswersA, B, C

Data integrity validation is critical to ensure the backup is usable and the recovery process works.

Why this answer

A non-destructive DR drill for Spanner should test the ability to restore from a backup to a different region (simulating recovery), validate the restored data integrity, and update runbooks based on lessons learned. Failing over a read replica is not applicable to Spanner (it uses multi-region replication, not read replicas). Stopping the primary instance is destructive.

Changing leader region is a configuration change that may affect live traffic.

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