Part 8: (AZ Series) Availability Zones : Simple Latency Test

AWS Availability Zones: Simple latency test


We did a simple test to check the latency between Amazon Availability zones 1a and 1b (our account). 
The Test architecture had:

• Multiple Grinder Load Clients
• Tomcat Application Server and 1-RDS MySQL Database Server
• M1.large instance type was used for the Tomcat and RDS MySQL
• 100,000 txns generated in 60 seconds 
• Region: US-East , Availability Zones : 1A and 1B in our account
• In Practice Majority of Web/App EC2 and Master Database should reside in same AZ. For ease of testing purpose we have followed the above architecture.

Test 1: Observations

·         Java/Tomcat based App EC2 was launched on US-EAST-1A

·         RDS MySQL was launched on US-EAST-1A ( same availability zone)

·         Both were EC2 instances were m1.large capacity

·         100K txns/minute was generated from Tomcat to RDS instance

·         Average latency of 3 ms was observed for 100K txns in a single AZ setup

Test 2: Observations

·         Java/Tomcat based App EC2 was launched on US-EAST-1A

·         RDS MySQL was launched on US-EAST-1B (different availability zone)

·         Both were EC2 instances were m1.large capacity

·         100K txns/minute was generated from Tomcat to RDS instance

·         Average latency of 9 ms was observed for 100K txns in the multi-AZ setup.

·        Though it is roughly ~3X increase of latency from Test1, since the Average latency is in the range of single digit ms, it is suggested to use Multi-AZ deployments for applications requiring high availability.  Note: The observed ~3X latency difference will usually vary depending upon the Availability Zones (AZ origin / AZ destination /AWS Region) and it should not be treated as exact figure.

Other Related Articles :
(Full Article) Exploring Amazon Availability Zones 
Part 8: (AZ Series) Availability Zones : Simple Latency Test
Part 7: (AZ Series) AWS Availability Zones Usage charges
Part 6: (AZ Series) Guidelines for architecting applications across AWS Availability Zones
Part 5:(AZ Series) Availability Zone Names are logical names
Part 4: (AZ Series) How Amazon VPC uses Availability zones
Part 3: (AZ Series) How AWS Building blocks inherently leverage Availability Zones?
Part 2: (AZ Series) Why we should leverage AWS Availability Zones?
Part 1: (AZ Series) What is AWS Availability Zone ?