Table of Contents
- 1 When using strongly consistent reads in DynamoDB you are reading from the?
- 2 How are you charged for DynamoDB?
- 3 How many DynamoDB RCUs are required for a strongly consistent read of an 8 KB item?
- 4 How does DynamoDB achieve strong consistency?
- 5 Does DynamoDB charge per table?
- 6 Is DynamoDB more expensive than RDS?
- 7 What is strongly consistent read?
- 8 What are strongly consistent reads?
- 9 What is provisioned throughput capacity in Amazon DynamoDB?
- 10 How many read request units do I need for DynamoDB read consistency?
When using strongly consistent reads in DynamoDB you are reading from the?
Strongly Consistent Reads When you request a strongly consistent read, DynamoDB returns a response with the most up-to-date data, reflecting the updates from all prior write operations that were successful.
How are you charged for DynamoDB?
DynamoDB charges per GB of disk space a table consumes. The first 25 GB consumed per month is free, and prices start at $0.25 per GB-month thereafter.
What is the cost of throughput for a DynamoDB in AWS?
DynamoDB Standard table class
| On-Demand Throughput Type | Price |
|---|---|
| Write Capacity Units (WRU) | $1.25 per million write request units |
| Read Capacity Units (RRU) | $0.25 per million read request units |
How many DynamoDB RCUs are required for a strongly consistent read of an 8 KB item?
two RCUs
For example, a strongly consistent read of an 8 KB item would require two RCUs, an eventually consistent read of an 8 KB item would require one RCU, and a transactional read of an 8 KB item would require four RCUs.
How does DynamoDB achieve strong consistency?
More explanation: DynamoDB (assuming it is similar to the database described in the Dynamo paper that Amazon released) uses a ring topology, where data is spread to many servers. Strong consistency is guaranteed because you directly query all relevant servers and get the current data from them.
Does DynamoDB support multi AZ?
By default AWS DynamoDB is a multi-AZ enabled service which means that your data is by default replicated across 3 data centers (minimum of 2 AZs) but for cross-region, you need to enable DynamoDB global tables (DynamoDB Streams).
Does DynamoDB charge per table?
How Does AWS DynamoDB Pricing Work?
| Provisioned | On-Demand | |
|---|---|---|
| Global tables (Tables duplicated across regions) | $0.000975 per rWCU | $1.875 per million rWCU |
| Data storage (For tables) | First 25GB per mth are free Each GB after is $0.25 per GB per mth |
Is DynamoDB more expensive than RDS?
Costs. Storing data in DynamoDB can be expensive when compared to other solutions like RDS or Aurora. For example storing 1TB of data in Aurora costs $100/month. By comparison, 1TB in DynamoDB costs $250/month.
How is WCU calculated?
Provisioned Mode 1 write capacity unit (WCU) = 1 write of up to 1 KB/s. 2 WCUs = 1 transactional write request (one write per second) for items up to 1 KB.
What is strongly consistent read?
A strongly consistent read returns a result that reflects all writes that received a successful response prior to the read. From the definition above, what I get is that a strong consistent read will return the latest write value.
What are strongly consistent reads?
What is on-demand capacity mode in AWS DynamoDB?
For a list of AWS Regions where DynamoDB on-demand is available, see Amazon DynamoDB Pricing. DynamoDB tables using on-demand capacity mode automatically adapt to your application’s traffic volume. On-demand capacity mode instantly accommodates up to double the previous peak traffic on a table.
What is provisioned throughput capacity in Amazon DynamoDB?
When you create a new provisioned table in Amazon DynamoDB, you must specify its provisioned throughput capacity. This is the amount of read and write activity that the table can support. DynamoDB uses this information to reserve sufficient system resources to meet your throughput requirements.
How many read request units do I need for DynamoDB read consistency?
For example, if your item size is 8 KB, you require 2 read request units to sustain one strongly consistent read, 1 read request unit if you choose eventually consistent reads, or 4 read request units for a transactional read request. To learn more about DynamoDB read consistency models, see Read Consistency.
What are the disadvantages of DynamoDB’s consistency?
However, this consistency comes with some disadvantages: A strongly consistent read might not be available if there is a network delay or outage. In this case, DynamoDB may return a server error (HTTP 500).