RDS Multi-AZ vs Read Replica

DB instances replicas tin be created in two ways Multi-AZ & Read Replica, which provide high availability, durability, and scalability to RDS.RDS Read Replicas vs Multi-AZ

Multi-AZ deployments

  • RDS Multi-AZ deployment provides high availability, durability, and failover back up
  • RDS automatically provisions and manages a synchronous standby instance in a different AZ (independent infrastructure in a physically carve up location)
  • RDS automatically fails over to the standby so that database operations can resume quickly without administrative intervention in instance of
    • Planned database maintenance
    • Software patching
    • Rebooting of the Primary instance
    • Primary DB case connectivity or host failure, or an
    • Availability Zone failure
  • RDS maintains the same endpoint for the DB Example after a failover, and so the application tin resume database operation without the need for manual administrative intervention.

Refer web log post @ RDS Multi-AZ deployment

RDS Read Replicas

  • Read replicas enable increased scalability and database availability in the case of an AZ failure.
  • Read Replicas permit rubberband scaling beyond the capacity constraints of a single DB instance for read-heavy database workloads
  • RDS read replicas tin can be Multi-AZ i.eastward. set upwardly with their own standby instances in a different AZ.
  • Load on the source DB instance can be reduced by routing read queries from applications to the Read Replica.
  • ane or more replicas of a given source DB Instance and serve loftier-volume application read traffic from multiple copies of your data, thereby increasing amass read throughput. Read replicas can also be promoted when needed to become standalone DB instances.
  • RDS uses DB engines' congenital-in replication functionality to create a special type of DB example chosen a Read Replica from a source DB instance. It uses the engines' native asynchronous replication to update the read replica whenever there is a change to the source DB instance.
  • Read replicas are bachelor in RDS for MySQL, MariaDB, PostgreSQL, Oracle, and SQL Server as well equally Aurora.

Refer blog mail service @ RDS Read Replicas

RDS Mulit-AZ vs Multi-Region vs Read Replicas

AWS Certification Examination Exercise Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated presently, so inquiry appropriately.
  • AWS examination questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. You lot are running a successful multi-tier spider web application on AWS and your marketing department has asked you to add a reporting tier to the awarding. The reporting tier will aggregate and publish status reports every 30 minutes from user-generated information that is being stored in your web applications database. You are currently running a Multi-AZ RDS MySQL example for the database tier. You as well take implemented ElastiCache equally a database caching layer betwixt the awarding tier and database tier. Please select the reply that will let you to successfully implement the reporting tier with every bit fiddling impact as possible to your database.
    1. Continually ship transaction logs from your principal database to an S3 bucket and generate the reports of the S3 saucepan using S3 byte range requests.
    2. Generate the reports past querying the synchronously replicated standby RDS MySQL instance maintained through Multi-AZ (Standby instance cannot be used as a scaling solution)
    3. Launch an RDS Read Replica connected to your Multi-AZ master database and generate reports past querying the Read Replica.
    4. Generate the reports by querying the ElastiCache database caching tier. (ElasticCache does not maintain full data and is merely a caching solution)
  2. A company is deploying a new two-tier web application in AWS. The visitor has limited staff and requires high availability, and the application requires complex queries and table joins. Which configuration provides the solution for the company'due south requirements?
    1. MySQL Installed on two Amazon EC2 Instances in a single Availability Zone (does non provide High Availability out of the box)
    2. Amazon RDS for MySQL with Multi-AZ
    3. Amazon ElastiCache (Merely a caching solution)
    4. Amazon DynamoDB (Not suitable for complex queries and joins)
  3. Your visitor is getting ready to do a major public announcement of a social media site on AWS. The website is running on EC2 instances deployed across multiple Availability Zones with a Multi-AZ RDS MySQL Extra Big DB Example. The site performs a high number of pocket-sized reads and writes per 2nd and relies on an eventual consistency model. After comprehensive tests you lot discover that at that place is read contention on RDS MySQL. Which are the best approaches to meet these requirements? (Choose two answers)
    1. Deploy ElastiCache in-memory enshroud running in each availability zone
    2. Implement sharding to distribute load to multiple RDS MySQL instances (this is only a read contention, the writes work fine)
    3. Increase the RDS MySQL Instance size and Implement provisioned IOPS (not scalable, this is only a read contention, the writes piece of work fine)
    4. Add an RDS MySQL read replica in each availability zone
  4. Your visitor has HQ in Tokyo and branch offices all over the globe and is using logistics software with a multi-regional deployment on AWS in Japan, Europe and US. The logistic software has a three-tier architecture and currently uses MySQL v.six for data persistence. Each region has deployed its own database. In the HQ region you run an hourly batch process reading data from every region to compute cantankerous-regional reports that are sent by email to all offices this batch process must be completed as fast equally possible to quickly optimize logistics. How do you build the database architecture in gild to meet the requirements?
    1. For each regional deployment, utilize RDS MySQL with a principal in the region and a read replica in the HQ region
    2. For each regional deployment, apply MySQL on EC2 with a principal in the region and ship hourly EBS snapshots to the HQ region
    3. For each regional deployment, use RDS MySQL with a chief in the region and send hourly RDS snapshots to the HQ region
    4. For each regional deployment, utilize MySQL on EC2 with a chief in the region and use S3 to copy information files hourly to the HQ region
    5. Utilise Directly Connect to connect all regional MySQL deployments to the HQ region and reduce network latency for the batch process
  5. What would happen to an RDS (Relational Database Service) Multi-Availability Zone deployment if the primary DB instance fails?
    1. IP of the primary DB Case is switched to the standby DB Case.
    2. A new DB case is created in the standby availability zone.
    3. The canonical name record (CNAME) is inverse from primary to standby.
    4. The RDS (Relational Database Service) DB instance reboots.
  6. Your business is building a new application that will store its entire customer database on a RDS MySQL database, and will have diverse applications and users that will query that data for different purposes. Large analytics jobs on the database are likely to cause other applications to not be able to get the query results they need to, before time out. Also, as your data grows, these analytics jobs volition offset to take more than time, increasing the negative outcome on the other applications. How do you solve the contention issues between these different workloads on the same data?
    1. Enable Multi-AZ mode on the RDS instance
    2. Use ElastiCache to offload the analytics job data
    3. Create RDS Read-Replicas for the analytics work
    4. Run the RDS instance on the largest size possible
  7. Will my standby RDS case be in the same Availability Zone as my primary?
    1. Only for Oracle RDS types
    2. Yep
    3. Only if configured at launch
    4. No
  8. Is creating a Read Replica of another Read Replica supported?
    1. Only in certain regions
    2. Just with MySQL based RDS
    3. Only for Oracle RDS types
    4. No
  9. A user is planning to ready up the Multi-AZ feature of RDS. Which of the below mentioned weather condition won't have reward of the Multi-AZ feature?
    1. Availability zone outage
    2. A manual failover of the DB instance using Reboot with failover choice
    3. Region outage
    4. When the user changes the DB case'south server type
  10. When yous run a DB Example every bit a Multi-AZ deployment, the "_____" serves database writes and reads
    1. secondary
    2. backup
    3. stand up by
    4. primary
  11. When running my DB Instance as a Multi-AZ deployment, can I apply the standby for read or write operations?
    1. Yes
    2. Only with MSSQL based RDS
    3. Only for Oracle RDS instances
    4. No
  12. Read Replicas require a transactional storage engine and are only supported for the _________ storage engine
    1. OracleISAM
    2. MSSQLDB
    3. InnoDB
    4. MyISAM
  13. A user is configuring the Multi-AZ characteristic of an RDS DB. The user came to know that this RDS DB does not use the AWS technology, merely uses server mirroring to reach replication. Which DB is the user using right now?
    1. MySQL
    2. Oracle
    3. MS SQL
    4. PostgreSQL
  14. If I have multiple Read Replicas for my principal DB Instance and I promote one of them, what happens to the rest of the Read Replicas?
    1. The remaining Read Replicas will still replicate from the older master DB Instance
    2. The remaining Read Replicas will exist deleted
    3. The remaining Read Replicas will exist combined to ane read replica
  15. If you have chosen Multi-AZ deployment, in the outcome of a planned or unplanned outage of your primary DB Instance, Amazon RDS automatically switches to the standby replica. The automatic failover mechanism simply changes the ______ record of the principal DB Instance to indicate to the standby DB Instance.
    1. DNAME
    2. CNAME
    3. TXT
    4. MX
  16. When automatic failover occurs, Amazon RDS will emit a DB Instance event to inform you that automatic failover occurred. You can apply the _____ to return data about events related to your DB Example
    1. FetchFailure
    2. DescriveFailure
    3. DescribeEvents
    4. FetchEvents
  17. The new DB Instance that is created when you promote a Read Replica retains the backup window period.
    1. TRUE
    2. Simulated
  18. Volition I be alerted when automatic failover occurs?
    1. Only if SNS configured
    2. No
    3. Yes
    4. Merely if Cloudwatch configured
  19. Can I initiate a "forced failover" for my MySQL Multi-AZ DB Instance deployment?
    1. Only in sure regions
    2. Only in VPC
    3. Yes
    4. No
  20. A user is accessing RDS from an application. The user has enabled the Multi-AZ feature with the MS SQL RDS DB. During a planned outage how will AWS ensure that a switch from DB to a standby replica will not affect admission to the application?
    1. RDS will take an internal IP which volition redirect all requests to the new DB
    2. RDS uses DNS to switch over to standby replica for seamless transition
    3. The switch over changes Hardware and then RDS does not need to worry about access
    4. RDS will have both the DBs running independently and the user has to manually switch over
  21. Which of the following is role of the failover process for a Multi-AZ Amazon Relational Database Service (RDS) instance?
    1. The failed RDS DB instance reboots.
    2. The IP of the primary DB case is switched to the standby DB instance.
    3. The DNS record for the RDS endpoint is changed from master to standby.
    4. A new DB instance is created in the standby availability zone.
  22. Which of these is non a reason a Multi-AZ RDS instance will failover?
    1. An Availability Zone outage
    2. A manual failover of the DB instance was initiated using Reboot with failover
    3. To autoscale to a higher instance course (Refer link)
    4. Master database corruption occurs
    5. The main DB instance fails
  23. Yous need to scale an RDS deployment. You are operating at 10% writes and 90% reads, based on your logging. How all-time can y'all scale this in a unproblematic mode?
    1. Create a second master RDS instance and peer the RDS groups.
    2. Cache all the database responses on the read side with CloudFront.
    3. Create read replicas for RDS since the load is mostly reads.
    4. Create a Multi-AZ RDS installs and route read traffic to standby.
  24. How does Amazon RDS multi Availability Zone model work?
    1. A second, standby database is deployed and maintained in a dissimilar availability zone from master, using synchronous replication. (Refer link)
    2. A 2d, standby database is deployed and maintained in a different availability zone from master using asynchronous replication.
    3. A 2d, standby database is deployed and maintained in a different region from main using asynchronous replication.
    4. A 2d, standby database is deployed and maintained in a different region from master using synchronous replication.
  25. A customer is running an application in The states-West (Northern California) region and wants to setup disaster recovery failover to the Asian Pacific (Singapore) region. The customer is interested in achieving a depression Recovery Point Objective (RPO) for an Amazon RDS multi-AZ MySQL database instance. Which arroyo is best suited to this need?
    1. Synchronous replication
    2. Asynchronous replication
    3. Route53 health checks
    4. Copying of RDS incremental snapshots
  26. A user is using a small MySQL RDS DB. The user is experiencing high latency due to the Multi AZ feature. Which of the below mentioned options may not help the user in this state of affairs?
    1. Schedule the automated back up in non-working hours
    2. Use a large or higher size instance
    3. Utilize PIOPS
    4. Take a snapshot from standby Replica
  27. Are Reserved Instances available for Multi-AZ Deployments?
    1. Just for Cluster Compute instances
    2. Yes for all instance types
    3. But for M3 instance types
  28. My Read Replica appears "stuck" afterward a Multi-AZ failover and is unable to obtain or apply updates from the source DB Instance. What do I do?
    1. You will need to delete the Read Replica and create a new one to supplant information technology.
    2. You will need to disassociate the DB Engine and re-associate it.
    3. The case should be deployed to Single AZ so moved to Multi-AZ once again
    4. You will need to delete the DB Instance and create a new one to supervene upon information technology.
  29. What is the charge for the data transfer incurred in replicating information between your primary and standby?
    1. No charge. It is free.
    2. Double the standard information transfer charge
    3. Same equally the standard data transfer charge
    4. Half of the standard data transfer charge
  30. A user has enabled the Multi-AZ characteristic with the MS SQL RDS database server. Which of the below mentioned statements will help the user understand the Multi-AZ characteristic better?
    1. In a Multi-AZ, AWS runs 2 DBs in parallel and copies the data asynchronously to the replica copy
    2. In a Multi-AZ, AWS runs ii DBs in parallel and copies the data synchronously to the replica copy
    3. In a Multi-AZ, AWS runs only one DB but copies the data synchronously to the standby replica
    4. AWS MS SQL does non support the Multi-AZ feature
  31. A company is running a batch analysis every hour on their main transactional DB running on an RDS MySQL instance to populate their central Data Warehouse running on Redshift. During the execution of the batch their transactional applications are very ho-hum. When the batch completes they need to update the peak direction dashboard with the new data. The dashboard is produced by another organisation running on-premises that is currently started when a manually sent email notifies that an update is required The on-bounds system cannot be modified because is managed past some other team. How would yous optimize this scenario to solve performance issues and automate the process as much as possible?
    1. Supervene upon RDS with Redshift for the batch analysis and SNS to notify the on-bounds system to update the dashboard
    2. Replace RDS with Redshift for the batch assay and SQS to ship a message to the on-bounds system to update the dashboard
    3. Create an RDS Read Replica for the batch assay and SNS to notify me on-bounds organization to update the dashboard
    4. Create an RDS Read Replica for the batch assay and SQS to send a bulletin to the on-premises organisation to update the dashboard.