Domain 3 - Technology ( 1 of 3 ) Flashcards
You want to improve the resilience of your EC2 web server. Which of the following is the most effective and efficient approach?
- Launch parallel, load-balanced instances in multiple Availability Zones within a single AWS Region.
- Launch parallel, auto scaled instances in multiple Availability Zones within a single AWS Region.
- Launch parallel, auto scaled instances in multiple AWS Regions.
- Launch parallel, load-balanced instances in multiple AWS Regions.
- Launch parallel, load-balanced instances in multiple Availability Zones within a single AWS Region.
Auto scaling is an important working element of application high availability, but it’s not what most directly drives it (that’s load balancing). The most effective and efficient way to get the job done is through parallel, load-balanced instances in multiple Availability Zones, not Regions.
What is the function of an EC2 AMI?
- To serve as a source image from which an instance’s primary storage volume is built
- To define the hardware profile used by an EC2 instance
- To serve as an instance storage volume for high-volume data processing operations
- To define the way data streams are managed by EC2 instances
- To serve as a source image from which an instance’s primary storage volume is built
An instance’s hardware profile is defined by the instance type. High-volume (or low-volume) data processing operations and data streams can be handled using any storage volume or on any instance (although some may be better optimized than others).
Which of the following Relational Database Service (RDS) features can help you achieve a monthly availability of 99.95 percent?
- Read replicas
- Point-in-time recovery
- Multi-AZ
- Horizontal scaling
- Multi-AZ
Multi-AZ lets your database withstand the failure of an RDS instance, even if the failure is due to an entire Availability Zone failing. Read replicas are a way to achieve horizontal scaling to improve performance of database reads but don’t increase availability. Point-in-time recovery allows you to restore a database up to a point in time but doesn’t increase availability.
What is true regarding a DynamoDB partition? (Select TWO.)
- It’s a way to uniquely identify an item in a table
- It’s replicated across multiple Availability Zones.
- It’s stored within a table.
- It’s backed by solid-state drives.
- It’s replicated across multiple Availability Zones.
- It’s backed by solid-state drives.
A partition is an allocation of storage backed by solid-state drives and replicated across multiple Availability Zones. Tables are stored across partitions, but tables do not contain partitions. A primary key, not a partition, is used to uniquely identify an item in a table.
What is the minimum monthly availability for DynamoDB in a single Region?
- 99.95 percent
- 99.0 percent
- 99.9 percent
- 99.99 percent
The minimum monthly availability for DynamoDB is 99.99 percent in a single Region. It’s not 99.95 percent, 99.9 percent, or 99.0 percent.
- 99.99 percent
The minimum monthly availability for DynamoDB is 99.99 percent in a single Region. It’s not 99.95 percent, 99.9 percent, or 99.0 percent.
Which of the following statements is true regarding a DynamoDB table?
- Items in a table don’t have to have all the same attributes.
- Items in a table can have duplicate values for the primary key.
- It can store only one data type.
- When you create a table, you must define the maximum number of items that it can store
.
- Items in a table don’t have to have all the same attributes.
Items in a DynamoDB table can have different attributes. For example, one item can have five attributes, while another has only one. A table can store items containing multiple data types. There’s no need to predefine the number of items in a table. Items in a table can’t have duplicate primary keys.
Which configuration parameters can you adjust to improve write performance against a DynamoDB table? (Select TWO.)
- Decrease read capacity units (RCU)
- Increase read capacity units
- Decrease write capacity units
- Increase write capacity units (WCU)
- Enable DynamoDB Auto Scaling
- Increase write capacity units (WCU)
- Enable DynamoDB Auto Scaling
Increasing WCU or enabling Auto Scaling will improve write performance against a table. Increasing or decreasing RCU won’t improve performance for writes. Decreasing WCU will make write performance worse
Which DynamoDB operation is the most read-intensive?
- Query
- Write
- Scan
- Update
- Scan
A scan requires reading every partition on which the table is stored. A query occurs against the primary key, enabling DynamoDB to read only the partition where the matching item is stored. Writing and updating an item are not read-intensive operations.
Which of the following would be appropriate to use for a primary key in a DynamoDB table that stores a customer list?
- The customer’s city
- The customer’s full name
Correct Answer - A randomly generated customer ID number
- The customer’s phone number
The customer’s city
The customer’s full name
Correct Answer
A randomly generated customer ID number
The customer’s phone number
A primary key must be unique within a table. A full name, phone number, or city may not be unique, as some customers may share the same name or phone number. A randomly generated customer ID number would be unique and appropriate for use as a primary key.
UnansweredQuestion 10
0 / 1 pts
Which type of Redshift node uses magnetic storage?
- Dense compute
- Cost-optimized
- Dense storage
- Dense memory
-Dense compute
Dense compute nodes use magnetic disks. Dense storage nodes use SSDs. There are no such nodes as dense memory or cost-optimized.
UnansweredQuestion 11
0 / 1 pts
Which Redshift feature can analyze structured data stored in S3?
Amazon RDS
Redshift S3
Correct Answer
- Redshift Spectrum
- Amazon Athena
- Redshift Spectrum
Redshift Spectrum can analyze structured data stored in S3. There is no such service as Redshift S3. Amazon Athena can analyze structured data in S3, but it’s not a feature of Redshift. Amazon RDS doesn’t analyze data stored in S3.
What is the term for a relational database that stores large amounts of structured data from a variety of sources for reporting and analysis?
- Dense storage node
- Report cluster
- Data warehouse
- Data storehouse
- Data warehouse
A data warehouse stores large amounts of structured data from other relational databases. It’s not called a data storehouse or a report cluster. Dense storage node is a type of Redshift compute node.
