CCNA Management and Operations Questions

Option B is correct because adding read replicas distributes read traffic, reducing CPU load on the primary. Option A is wrong because increasing retention does not reduce CPU. Option C is wrong because disabling persistence reduces durability but does not significantly reduce CPU.

Option D is wrong because enabling encryption adds CPU overhead.

Option C is correct because AWS DMS can replicate ongoing changes and allow a short cutover window. Option A is wrong because AWS SCT does not handle data migration. Option B is wrong because restoring a snapshot takes longer than 2 hours for 500 GB.

Option D is wrong because Export/Import requires downtime and is slow.

Option C is correct because Performance Insights provides a dashboard to analyze database performance and identify top SQL queries by load. Option A is wrong because RDS Enhanced Monitoring shows OS metrics, not specific queries. Option B is wrong because CloudWatch Logs collects logs but does not analyze query performance.

Option D is wrong because the slow query log must be enabled and analyzed separately.

Option A is correct because a sudden spike in write latency often indicates that the storage volume has exhausted its burst credits and is now using baseline performance, which may be slower. Option B is incorrect because a large number of connections typically causes increased CPU and memory usage, not necessarily a latency spike. Option C is incorrect because a Multi-AZ failover would cause a brief downtime, not a latency spike.

Option D is incorrect because a snapshot would cause I/O suspension, not a latency spike.

Manual snapshots are retained indefinitely until deleted. Automated backups have a max retention of 35 days. Exporting to S3 is an option but not directly a backup retention method; you can export snapshots to S3, but manual snapshots are the standard way to retain backups long-term.

EC2 instance backups are not applicable.

Option A is correct because adding nodes distributes data and workload, improving performance and increasing storage capacity. Option B is wrong because VACUUM only reclaims space from deleted rows; it does not add capacity. Option C is wrong because compression is applied during COPY; re-encoding existing data requires unloading and reloading.

Option D is wrong because DISTSTYLE ALL replicates data to all nodes, which increases storage usage and may not help.

Option C is correct because using the RDS DNS CNAME record (which points to the primary instance and automatically updates after failover) ensures connections are redirected. Option A is wrong because modifying the connection string manually is not automated. Option B is wrong because a custom DNS solution adds complexity and is unnecessary.

Option D is wrong because the RDS endpoint is dynamic and not static; the DNS record handles the failover.

Option C is correct because the policy allows actions on DB snapshots, but automated snapshots have the resource type 'automated-snapshot' and require explicit resource ARN instead of '*'. Option A is wrong because the policy already includes the necessary actions. Option B is wrong because the issue is not about cross-region copying.

Option D is wrong because the issue is not about manual snapshots.

Option C is correct because in on-demand mode, throttling can occur if a single partition key receives more than 1,000 WCU or 3,000 RCU. Adjusting the partition key design to spread the workload more evenly can resolve throttling. Option A is wrong because the table is on-demand, so switching to provisioned capacity might not help if the access pattern is uneven.

Option B is wrong because the GSI inherits throttling from the base table; adding more GSI capacity is not applicable in on-demand mode. Option D is wrong because DynamoDB Streams do not directly affect throttling.

Option D is correct because AWS DMS can perform live migration with minimal downtime. Option A is wrong because AWS SCT helps with schema conversion but not data migration. Option B is wrong because Export/Import from Oracle dump requires downtime.

Option C is wrong because AWS Snowball is for offline data transfer, which introduces downtime.

Using Aurora cloning creates a copy that shares storage with the source, minimizing cost and avoiding performance impact. Option A is correct. Option B (snapshot and restore) creates a full copy, costing more.

Option C (DMS) adds cost and overhead. Option D (read replica and promote) would impact production replication.

Increasing the provisioned read capacity directly addresses throttling by allowing more reads per second. Option B is wrong because DynamoDB Accelerator (DAX) requires code changes to use. Option C is wrong because eventually consistent reads are already used.

Option D is wrong because using strongly consistent reads would increase RCU consumption, worsening throttling.

Option B is correct. The output shows the instance is a read replica (ReadReplicaSourceDBInstanceIdentifier is set), which means it is read-only and cannot accept writes. Option A is wrong because Multi-AZ does not affect write capability.

Option C is wrong because storage encryption does not prevent writes. Option D is wrong because insufficient IOPS would not make it read-only.

Options A and B are correct. 'ThrottledGetRecords' and 'ThrottledPutRecords' are CloudWatch metrics that directly indicate throttled read and write requests. Option C is incorrect because 'ReadThrottleEvents' is not a standard DynamoDB metric. Option D is incorrect because 'ProvisionedReadCapacityUnits' is for provisioned mode.

Option E is incorrect because 'ConsumedWriteCapacityUnits' shows consumed capacity, not throttling.

Option A is correct because increasing the instance size provides more IOPS capacity, which can reduce write latency if the instance is hitting IOPS limits. Option B is incorrect because enabling Multi-AZ adds a standby but does not increase write IOPS capacity on the primary. Option C is incorrect because increasing the storage size may increase IOPS if using gp2 but not necessarily, and the issue is IOPS, not storage capacity.

Option D is incorrect because the instance class is already optimized for memory; the issue is I/O, not memory.

Option B is correct because DynamoDB auto scaling adjusts capacity based on actual traffic patterns, preventing throttling while optimizing cost. Option A is wrong because application-level queuing adds latency. Option C is wrong because on-demand mode is cost-inefficient for predictable spikes.

Option D is wrong because increasing provisioned capacity manually is not automatic.

Option A is correct because using Application Auto Scaling scheduled scaling allows pre-scaling capacity before the spike. Option B is wrong because DAX is for reads. Option C is wrong because on-demand may be costlier but solves unpredictability; for predictable spikes, scheduled scaling is better.

Option D is wrong because increasing max capacity alone doesn't pre-scale.

Option A is correct because RDS requires free storage for automated backups and logs; insufficient free storage causes backup failure. Option B is wrong because backup retention does not consume storage. Option C is wrong because snapshot storage is separate.

Option D is wrong because transaction logs accumulate in allocated storage.

Option A is correct because lowering the minimum to 200 RCUs ensures auto scaling does not scale below the actual usage, reducing provisioned capacity costs. Option B is wrong because decreasing the maximum could cause throttling during spikes. Option C is wrong because increasing the minimum would increase costs unnecessarily.

Option D is wrong because disabling auto scaling would require manual management and may lead to over-provisioning.

Option A is correct because an explicit deny overrides any allow. Option B is wrong because the simulation does not check network conditions. Option C is wrong because the DBA can describe, so there is an allow for that action.

Option D is wrong because the resource ARN is correct for the DB instance.

Performance Insights provides a dashboard to analyze database performance and identify slow queries. CloudWatch Logs (A) is for logs, not query analysis. RDS Enhanced Monitoring (B) provides OS metrics, not query details.

AWS Trusted Advisor (D) provides best-practice checks, not query analysis.

Options A, C, and E are correct. Option A: AWS DMS with CDC allows ongoing replication with minimal downtime. Option C: Using AWS SCT helps convert the schema if needed.

Option E: Using an AWS Snowball Edge device for initial load reduces the time for large data transfer over slow internet. Option B is wrong because a VPN alone does not migrate data. Option D is wrong because a read replica is not a migration tool; it is a feature of Aurora.

Option D is correct because global tables eventually replicate asynchronously; network latency between regions can cause delays. Option A is wrong because conflict resolution does not cause delays. Option B is wrong because throughput is separate per region.

Option C is wrong because Streams are used for replication, not the cause of delay.

Option D is correct. Adding DeletionProtection: true enables deletion protection. Option A is wrong because DeletionPolicy is a CloudFormation attribute, not a property.

Option B is wrong because PreventRDSDeletion is not a valid property. Option C is wrong because the syntax is incorrect.

Option B is correct because AWS DMS supports ongoing replication to minimize downtime during migration. Option A is wrong because AWS Snowball is for large data transfers but does not support ongoing replication. Option C is wrong because S3 is not a migration tool.

Option D is wrong because RDS does not natively support Oracle Data Pump directly; DMS is the recommended service.

Option D is correct because on-demand tables can still throttle if a single partition receives more than 3,000 RCU or 1,000 WCU. Using adaptive capacity with a more uniform partition key distributes traffic. Option A is wrong because on-demand does not require adjusting RCU/WCU.

Option B is wrong because auto scaling is for provisioned capacity. Option C is wrong because DAX is a caching layer that reduces read load but does not eliminate throttling for hot partitions.

Option A is correct because the Sum metric over 1-minute period represents the total number of connections during that minute. A Sum of 200 indicates that at some point during the minute, connections exceeded the max_connections of 150, causing failures. Option B is wrong because the metric shows Sum, not average.

Option C is wrong because connection pooling reduces connections, not increases. Option D is wrong because the metric clearly shows high connection counts.

Option A is correct because enabling backup compression reduces backup size and speeds up transfers. Option B is correct because using Provisioned IOPS improves I/O performance for backups. Option C is wrong because increasing retention does not improve performance.

Option D is wrong because disabling Multi-AZ reduces availability. Option E is wrong because using a smaller instance class would worsen performance.

Option C is correct because Performance Insights provides a dashboard to identify top queries by load. Option A is wrong because it shows connections, not query performance. Option B is wrong because CloudWatch logs show slow queries but not in real-time.

Option D is wrong because RDS events show instance events, not query load.

Option D is correct because data skew causes some slices to have more data than others, leading to slower queries. Recreating the table with a different distribution style can help. Option A is incorrect because vacuum reclaims space and analyzes statistics, but does not fix data skew.

Option B is incorrect because modifying sort keys can improve query performance but does not address data skew. Option C is incorrect because adding more nodes does not automatically redistribute existing data; skew persists.

Option A is correct because the primary continues to accept writes independently; the secondary failure does not affect primary operations. Option B is wrong because failover is not automatic for read replicas. Option C is wrong because the primary does not become read-only.

Option D is wrong because write operations continue.

AWS DMS with ongoing replication (change data capture) can capture changes and replicate them to S3. Option B (AWS Glue) is for ETL jobs, not real-time CDC. Option C (Amazon Kinesis Data Streams) could ingest data but requires additional configuration.

Option D (Amazon RDS for SQL Server replication) does not directly write to S3.

Option C is correct. The explicit Deny overrides the Allow, so the user cannot delete items. Option A is wrong because Deny takes precedence.

Option B is wrong because the Deny explicitly restricts deletion. Option D is wrong because the policy explicitly denies deletion.

Option D is correct because DynamoDB auto scaling adjusts capacity based on actual usage and can handle predictable spikes with minimal cost. Option A is wrong because switching to on-demand can be more expensive for predictable workloads. Option B is wrong because increasing capacity manually requires monitoring and intervention.

Option C is wrong because SQS does not directly handle DynamoDB write throttling.

Option D is correct. Adding a read replica offloads read traffic from the primary instance, reducing latency. Option A is wrong because Multi-AZ does not improve read performance; the standby is not used for reads.

Option B is wrong because increasing storage may improve throughput but not resolve read contention. Option C is wrong because gp3 provides consistent performance but does not solve read scaling.

Option B is correct because choosing an appropriate distribution style (e.g., KEY or EVEN) can reduce data skew and improve performance. Option A is wrong while sorting can help query performance, it does not directly address skew. Option C is wrong because adding more nodes may not resolve skew.

Option D is wrong because compression reduces storage, not skew.

Option C is correct because point-in-time recovery restores the instance to a time before the deletion, and you can then extract the table. Option A is wrong because automated backups are not directly accessible as files. Option B is wrong because restoring from a snapshot would require a snapshot taken before deletion, which may not exist if the last snapshot was after deletion.

Option D is wrong because the 'deleted' table is not in the current database.

Option C is correct because adding more nodes to the cluster distributes the workload and improves parallelism. Option A is wrong because using a single node, distributing data across slices is limited. Option B is wrong because compression is already used typically.

Option D is wrong because VACUUM reclaims space but does not significantly improve performance for large workloads.

Option A is correct because creating a read replica offloads read traffic from the primary instance, reducing CPU utilization, and replicas can be promoted later if needed. Option B is wrong because modifying the DB instance class requires downtime. Option C is wrong because Multi-AZ is for high availability, not read scaling.

Option D is wrong because caching alone may not reduce CPU utilization caused by database queries.

Option C is correct. When automated backups are enabled, you can restore a DB instance to any point within the retention period, even after deletion. The deleted instance is retained for the backup retention period.

Option A is wrong because point-in-time recovery does not require a manual snapshot. Option B is wrong because a manual snapshot was not taken. Option D is wrong because you cannot recover from the Recycle Bin for RDS instances; RDS does not use the Recycle Bin.

Option C is correct because the default max_connections for Aurora MySQL is based on memory, and with 8 GB, it is about 800. A spike exceeding that can exhaust resources. Option A is wrong because storage auto-scaling is seamless.

Option B is wrong because burst balance applies to gp2 volumes, but Aurora uses cluster storage. Option D is wrong because replica lag would affect reads, not make the instance unresponsive.

AWS DMS can handle ongoing replication to minimize downtime. AWS SCT can convert the schema if needed, and AWS DMS can migrate data. AWS Snowball is for offline data transfer, which may not be needed with Direct Connect.

AWS RDS is the target, not a migration service. AWS DataSync is for file data, not databases. The correct options are B and D.

Option C is correct because creating a read replica with the new version, promoting it, and then redirecting traffic minimizes downtime. Option A is wrong because it causes downtime. Option B is wrong because modifying the DB instance directly causes downtime during the upgrade.

Option D is wrong because snapshot restore takes time and causes data loss for changes after the snapshot.

Option B is correct because write sharding on the GSI partition key can cause hot partitions. Option A is wrong because read capacity on the GSI does not affect writes. Option C is wrong because write capacity on the table is separate from GSI.

Option D is wrong because the issue is about throttling on GSI, not table.

Option B is correct because adding a read replica offloads read traffic from the primary instance, reducing latency. Option A is wrong because Multi-AZ is for high availability, not read scaling. Option C is wrong because increasing storage size may improve IOPS but does not directly address read load.

Option D is wrong because enabling Performance Insights is for monitoring, not performance improvement.

Options B and D are correct. Option B: Pre-creating a global table can distribute write traffic across regions, reducing load on a single table. Option D: Using DynamoDB Accelerator (DAX) can offload read traffic, reducing read capacity consumption.

Option A is wrong because switching to provisioned capacity requires capacity planning but does not automatically prevent throttling. Option C is wrong because increasing read capacity units is not applicable to on-demand mode. Option E is wrong because decreasing write capacity is counterproductive.

Option A is correct for schema conversion. Option B is correct for ongoing replication. Option C is correct for data migration.

Option D is incorrect because it is for file transfer. Option E is incorrect because it is for large data transfer.

Option C is correct. The latest restorable time is 2023-03-15T04:30:00Z, which is within the backup window. Option A is wrong because it is after the latest restorable time.

Option B is wrong because it is earlier than the latest restorable time. Option D is wrong because the backup window ends at 06:00, but the latest restorable time is 04:30.

Option A (increasing the number of nodes) and Option C (distributing data evenly) are correct. Option B is incorrect because Sort keys affect order, not disk spills. Option D is incorrect because WLM queues affect concurrency, not disk operations.

Option E is incorrect because column compression reduces storage but may not reduce disk spills.

Option C is correct. The error indicates the flash recovery area is full. The most efficient automated way is to modify the RDS DB instance to increase allocated storage, which also increases the recovery area.

Option A is wrong because manually deleting logs is not automated. Option B is wrong because archiving to S3 is not a standard RDS feature. Option D is wrong because restarting does not free space.

Options A and D are correct because you can create a snapshot, copy it with encryption, and restore; or use DMS to migrate to an encrypted target. Option B is wrong because you cannot directly enable encryption on an existing instance. Option C is wrong because enabling encryption on a replica requires the source to be encrypted.

Option E is wrong because the console does not allow direct modification.

Option C is correct. AWS Database Migration Service (DMS) with ongoing replication minimizes downtime and supports cross-region migration. Option A is wrong because exporting to S3 and importing is time-consuming and does not support ongoing replication.

Option B is wrong because cross-region read replicas are not available for Oracle. Option D is wrong because RMAN backups are not integrated with AWS for cross-region migration.

A local secondary index (LSI) on score allows efficient sorting within a partition. A global secondary index (GSI) on score would not be efficient for per-player queries. The correct options are A and D.

Option B (GSI) would not help per-player sorting. Option C (scan) is inefficient. Option E (LSI on timestamp) is already present.

Option D is correct because Auto Scaling reacts to actual consumption, but there is a lag; sudden spikes throttle before capacity increases. Option A is wrong because Auto Scaling does not have a maximum limit issue. Option B is wrong because throttling is due to write capacity, not partitioning.

Option C is wrong because burst capacity is limited; sustained spikes require pre-warming or use of on-demand.

Option A is correct because DocumentDB supports MongoDB compatibility and can be used as target. Option B is correct because AWS DMS supports MongoDB to DocumentDB migration with ongoing replication. Option C is correct because setting up replication from the source reduces downtime.

Option D is wrong because sharding adds complexity. Option E is wrong because AWS Snowball is for offline data transfer, not minimal downtime.

Option B is correct because the issue is likely due to a hot partition caused by a single partition key. Option A is wrong because increasing read capacity does not help writes. Option C is wrong because on-demand capacity already handles large traffic, but throttling still occurs due to partition-level limits.

Option D is wrong because DAX is for caching reads, not writes.

Option A is correct because using a Global Secondary Index (GSI) with a different key can distribute traffic. Option D is correct because adding a GSI with 'game_id' as partition key can distribute writes if 'game_id' has high cardinality. Option B is wrong because increasing read capacity doesn't solve hot partition issues.

Option C is wrong because simple queries are fine. Option E is wrong because DAX caches reads, not writes.