[HTTPCORE-721] High CPU usage observed when the server closes the connection after responding with the Keep-alive header to a load test with large payload.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 4.4.15
• Component/s: HttpCore NIO
• Environment: JDK 8_261 and above
• Assignee: Unassigned
• Reporter: Sajinie Kavindya
• Created: 26/Jul/22 13:15
• Updated: 26/Jul/22 15:43
• Resolved: 26/Jul/22 13:24

Description

Hi,

In HTTPCoreNIO 4.4.15, for JDK 8_261 and above, we can observe a high CPU usage for the following scenario.

• Client behavior: sends POST/PUT requests with a payload greater than the buffer size. Should be a load test at least with two requests.
• Server behavior:  responds with the Connection: keep-alive header and immediately closes the connection using the connection close method.

Please note that for JDK version < JDK 8_261, this is not reproducible. In order to reproduce the issue, I have written a test server and a JMeter script to act as a client.

Reproducible steps:

1. TestServer.java - Run this main class, which starts the server on port 8253. (I have only changed the “completeResponse” method to close the connection at line #753).
2. HTTPClient.jmx - Start this JMeter script, which sends two POST requests to the server with a large payload.

Please let us know the validity of this scenario. For now, I am creating this as a Bug as high CPU usage is observed.

Thanks & Regards,
Sajinie