Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 247 discussion

Who would know this stuff man...

C,E "An active, long-running transaction can slow the process of creating the read replica. We recommend that you wait for long-running transactions to complete before creating a read replica. If you create multiple read replicas in parallel from the same source DB instance, Amazon RDS takes only one snapshot at the start of the first create action. When creating a read replica, there are a few things to consider. First, you must enable automatic backups on the source DB instance by setting the backup retention period to a value other than 0. This requirement also applies to a read replica that is the source DB instance for another read replica" https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html

To create a read replica for Amazon RDS for MySQL, the following prerequisites must be met: A. Enable binlog replication on the RDS primary node Required. RDS read replicas rely on MySQL binary log (binlog) replication. This setting is not enabled by default. You must set the DB parameter binlog_format to ROW and enable binary logging by modifying the parameter group. E. Enable automatic backups Required. Enabling automatic backups by setting backup retention > 0 is necessary to support point-in-time recovery and to allow the creation of read replicas. RDS uses the backup snapshot as a baseline to create the initial read replica. Why not "C. Allow long-running transactions to complete"? Not a prerequisite for creating a read replica. Might improve performance temporarily, but it’s unrelated to read replica setup.

Opção A: Habilite a replicação de log binário no nó primário do RDS A replicação de log binário é necessária para habilitar réplicas de leitura no RDS for MySQL. O banco de dados de origem precisa capturar e armazenar logs binários que serão usados para replicar alterações para as réplicas de leitura, E: Habilite backups automáticos na instância de origem definindo o período de retenção de backup como um valor diferente de 0 Backups automáticos devem estar habilitados na instância de origem para criar réplicas de leitura. Isso garante que a réplica possa ser criada a partir de um ponto consistente do banco de dados de origem

Allow long-running transactions to complete on the source DB instance.

Based on the official documentation, the correct steps to prepare for creating a read replica are: A. Enable binlog replication on the RDS primary node. C. Allow long-running transactions to complete on the source DB instance. E. Enable automatic backups on the source instance by setting the backup retention period to a value other than 0. These ensure smooth and efficient setup while adhering to AWS best practices. For more detailed information, you can refer to the AWS documentation: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.Create.html A (Enable binlog replication) is not a required manual step in Amazon RDS. Amazon RDS automatically manages this requirement during the creation of the read replica for MySQL and MariaDB.

Answer: CE. A: In Amazon RDS, binary logging is automatically enabled when creating a read replica. You don’t need to enable it manually. B: Read replicas are used for improving read performance, not for failover purposes. C: This ensures a clean state before replication begins. D: Global tables are part of Amazon DynamoDB, not Amazon RDS. E: RDS uses the automated backup feature to take a snapshot of the primary DB instance and initialize the replica.

A isn't correct because binary log is just for external DB instance.

Answer is C and E https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html

A. Enable binlog replication on the RDS primary node: Direct Impact: Enabling binlog replication is crucial for setting up read replicas, which will directly help in distributing the read load and improving read performance. E. Enable automatic backups on the source instance by setting the backup retention period to a value other than 0: Direct Impact: Automatic backups are necessary to ensure data integrity when creating read replicas. This setup is critical for maintaining consistent and reliable replicas.

B and D don't have anything to do with the question. E is a must have before doing major architecture changes A is not something you need to do explicitly when creating read replicas as it is managed by RDS C makes sense * I think the options are really badly worded which makes it confusing. I doubt this is a real question.

An active, long-running transaction can slow the process of creating the read replica. We recommend that you wait for long-running transactions to complete before creating a read replica. If you create multiple read replicas in parallel from the same source DB instance, Amazon RDS takes only one snapshot at the start of the first create action. When creating a read replica, there are a few things to consider. First, you must enable automatic backups on the source DB instance by setting the backup retention period to a value other than 0. This requirement also applies to a read replica that is the source DB instance for another read replica

To improve the read performance of a database in Amazon RDS for MySQL by adding a read replica, you should take the following actions: Enable binlog replication on the RDS primary node: This allows the primary node to stream its binary logs to the read replica, enabling data replication. A. Enable binlog replication on the RDS primary node. Allow long-running transactions to complete on the source DB instance: Before creating a read replica, it's advisable to let any long-running transactions complete to ensure consistency between the source and the replica. C. Allow long-running transactions to complete on the source DB instance. The other options are not directly related to setting up a read replica:

A - it's essential for continuous replication E - it's essential for setting up replication, initial data in replica is based on latest backup other options: B - we're not designing for HA, and it's related to mutli-AZ RDS deployments C - is this needed for adding read replica? D - it's not a dynamodb to create global table

A. Enabling binlog replication is not something you need to do manually before creating a read replica. Amazon RDS for MySQL manages replication internally, and it's not necessary to enable binlog replication explicitly. B. Choosing a failover priority is related to Multi-AZ configurations and automatic failover, but it is not specifically required when adding a read replica. D. Creating a global table and specifying AWS Regions is related to Aurora Global Databases, which is not the same as creating a read replica for a standard RDS instance.

**C. Long-running transactions can prevent the read replica from catching up with the source DB instance. Allowing these transactions to complete before creating the read replica can help ensure that the replica is able to stay synchronized with the source. **E. Automatic backups must be enabled on the source DB instance for read replicas to be created. This is done by setting the backup retention period to a value other than 0.

Bin log (binary log) is a specific terminology to MySQL, it is a write-only file that logs all history and used for purposes such as point-in-time recovery and transaction replication. Option A is technically correct but on AWS RDS, this MySQL feature is turned on by setting backup retention period > 0, that is why we must enable backup before replication can work (for MySQL, at least) => Option E is the more general answer for AWS RDS. Option C is just a recommendation from AWS official documentation, it is there to prevent data mismatch on primary and secondaries when the long-running transactions have not been complete yet.