Hi, I've tried to test the scenario of Arshiya Shariff: "With a payload of 200 bytes we were able to send 20K requests/sec with 200 users from Jmeter without any memory issue . On increasing the payload to 5Kb and the number of users to 1000 in Jmeter and sending 1000 requests per second , the heap of 20GB got filled in 2 minutes . With 200 users the memory is cleared in the G1 mixed GC itself , but with 1000 users the memory is not cleared in the mixed GC , it takes full GCs of 7 to 10 seconds to clear the memory. These cases were executed with maxThreads 200 in tomcat , so we tried increasing the maxThreads from 200 to 1000, but still GC was struggling ."
My Servlet looks like this: https://github.com/martin-g/http2-server-perf-tests/blob/f5e73d73a864d4c7dbcbbbe80024764352383116/java/tomcat/src/main/java/info/mgsolutions/tomcat/PlainTextServlet.java#L37-L54 And the Vegeta command I issue is: jq -ncM '{"method": "POST", "url": "https://localhost:8080/testbed/plaintext";, "body":"payload=Some payload" | @base64, header: {"Content-Type": ["application/x-www-form-urlencoded"]}}' | vegeta attack -format=json -http2 -rate=1 -max-workers=8 -insecure -duration=3s | vegeta encode > /tmp/http2.json; and vegeta report -type=json /tmp/http2.json | jq . The outcome is: { "latencies": { "total": 114369584, "mean": 38123194, "50th": 45737841, "90th": 62258803, "95th": 62258803, "99th": 62258803, "max": 62258803, "min": 6372940 }, "bytes_in": { "total": 24, "mean": 8 }, "bytes_out": { "total": 40, "mean": 13.333333333333334 }, "earliest": "2020-09-30T12:40:15.208111926+03:00", "latest": "2020-09-30T12:40:17.208170426+03:00", "end": "2020-09-30T12:40:17.253908267+03:00", "duration": 2000058500, "wait": 45737841, "requests": 3, "rate": 1.499956126283306, "throughput": 0.9776144183650195, "success": 0.6666666666666666, "status_codes": { "0": 1, "200": 2 }, "errors": [ "Post \"https://localhost:8080/testbed/plaintext\": http2: server sent GOAWAY and closed the connection; LastStreamID=3, ErrCode=ENHANCE_YOUR_CALM, debug=\"Connection [4], Too much overhead so the connection will be closed\"" ] } I.e. it sends 1 POST request every second for 3 seconds and this leads to GOAWAY+ENHANCE_YOUR_CALM ! >From my understanding on "overhead" this should happen if there are more SETTINGS|PING|WINDOW_UPDATE|PRIORITY frames than HTTP_HEADERS or DATA. I am not able to decrypt TLS data in Wireshark when the client is Vegeta, so I will try to debug it or to reproduce it with Firefox (to be able to use Wireframe). Any ideas why this happens ? Martin
