API Platform Gateway Performance

The performance of the WSO2 API Platform Gateway was evaluated using the following APIs, both of which invoke a simple Netty HTTP Echo Service. As the name suggests, the Netty service echoes back any request it receives.

• API without policies: An API configured with eight routes that directly forward requests to the backend service through the gateway.
• API with mediation policies: An API configured with the same eight routes, with a Set Header policy applied to both the request and response flows.

The performance tests were conducted with 100, 500, 800, and 1000 concurrent users, where concurrent users represent multiple clients accessing the gateway simultaneously. To evaluate the impact of different message sizes, tests were performed using payload sizes of 50 B, 1 KiB, 10 KiB, and 100 KiB. The backend response delay was configured to 0 ms.

Apache JMeter was used as the test client. Each test scenario was executed for 15 minutes, including a 3-minute warm-up period. Performance metrics were calculated after excluding the warm-up period from the analysis.

The following key metrics were used to evaluate gateway performance:

• Throughput: The number of API requests processed by the gateway per unit of time (requests per second).
• Response time: The end-to-end time taken to process an API request. The complete response time distribution, including the 90^th, 95^th, and 99^th percentile response times, was recorded and analyzed.

Deployment used for the test

The diagram below shows the deployment architecture used for the performance tests documented here.

Component	EC2 Instance Type	vCPU	Memory (GiB)
Apache JMeter Client	c5.2xlarge	8	16
Apache JMeter Servers	c5.2xlarge	8	16
Netty HTTP Backend	c5.2xlarge	8	16
WSO2 API Platform Gateway	c5.4xlarge	16	32

• The operating system is Amazon Linux 2023.11.
• Java version is Temurin JDK 21.

Performance test scripts

All scripts used to analyze results are in the following repository.

• https://github.com/wso2/performance-common.

Results

The tests were executed using the user counts and payload sizes described above across two concurrency levels. For each concurrency level, the gateway runtime was allocated the corresponding CPU resources before deploying the API Gateway test configurations. The table below summarizes the test scenarios covered in this document.

Test Scenario	CPU Allocation (Gateway Controller)	CPU Allocation (Gateway Runtime)	Router Concurrency	Test Results
1	1	2	2	Gateway runtime with two CPUs
2	1	4	4	Gateway runtime with four CPUs