Hello, I need help! Summary: We are conducting stress testing with Apache JMeter 5.6.3, and are experiencing JMeter errors once our wordpress server hits a certain number of users/threads (around 200). The higher the number of users/rps, the higher the percentage of errors would occur (8% to 40+%). It appears the errors aren't originating from the Wordpress server, but the JMeter HTTP4 Client.
**QUESTIONS**: 1. Is #2 below (updating user.properties and hc.parameters) the "correct" way to get around these JMeter Errors? 2. What pitfalls, if any, will incur from doing #2 below in our tests? Through trial and error, we found only two solutions that make the errors go away: 1. Working, but unacceptable: Disable Keep-Alive header in ALL JMX Http Requests (Unacceptable, as most web browsers will send the request so this isn't realistic). 2. Working, plus we don't need to update our JMX tests: We discovered a stackoverflow post that recommended editing the following files: a. JMeter/bin/user.properties: Add following lines: httpclient4.retrycount=1 hc.parameters.file=hc.parameters b. JMeter/bin/hc.parameters: Add following lines: http.connection.stalecheck$Boolean=true Additional Info: JMeter Version: 5.6.3 JMeter HTTP Request Client Implementation: HTTP4 JMeter JMX Test: A simple test with the root URL, and several /wp-content/ image and svg resources. JMeter Response Code: Non HTTP response code: org.apache.http.NoHttpResponseException JMeter Response Message: Non HTTP response message: some.server.com:443 failed to respond Server Info: 1. The org.apache.http.NoHttpResponseException shown in Apache JMeter doesn't correlate to any errors in the Apache WordPress logs. 2. At the time the errors occur, even at extreme loads of 20k+ users, the server's CPU and Memory usage never go above 20%. Other Things We Tried That Made No Difference: 1. Updating the HTTP Request Sampler's timeout. 2. Changing the HTTP Request headers content types around. 3. Updating the Apache/WordPress Server's Max Keep Alive Connection from 100 to 200.