Investigate flaky test-http-server-request-timeout-keepalive

[richardlau]

Test

test-http-server-request-timeout-keepalive

Platform

FreeBSD, macOS

Console output

17:13:37 not ok 1424 parallel/test-http-server-request-timeout-keepalive
17:13:37 ---
17:13:37 duration_ms: 3.487
17:13:37 severity: fail
17:13:37 exitcode: 1
17:13:37 stack: |-
17:13:37 node:assert:123
17:13:37 throw new AssertionError(obj);
17:13:37 ^
17:13:37 
17:13:37 AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:
17:13:37 + actual - expected
17:13:37 
17:13:37 + 'HTTP/1.1 200 OK\r\n' +
17:13:37 + 'Content-Type: text/plain\r\n' +
17:13:38 + 'Date: Thu, 14 Apr 2022 16:13:37 GMT\r\n' +
17:13:38 + 'Connection: close\r\n' +
17:13:38 + 'Transfer-Encoding: chunked\r\n' +
17:13:38 + '\r\n' +
17:13:38 + '0\r\n' +
17:13:38 + '\r\n'
17:13:38 - ''
17:13:38 at Socket.<anonymous> (/usr/home/iojs/build/workspace/node-test-commit-freebsd/nodes/freebsd12-x64/test/parallel/test-http-server-request-timeout-keepalive.js:82:12)
17:13:38 at Socket.<anonymous> (/usr/home/iojs/build/workspace/node-test-commit-freebsd/nodes/freebsd12-x64/test/common/index.js:438:15)
17:13:38 at Socket.emit (node:events:539:35)
17:13:38 at endReadableNT (node:internal/streams/readable:1344:12)
17:13:38 at process.processTicksAndRejections (node:internal/process/task_queues:82:21){
17:13:38 generatedMessage: true,
17:13:38 code: 'ERR_ASSERTION',
17:13:38 actual: 'HTTP/1.1 200 OK\r\n' +
17:13:38 'Content-Type: text/plain\r\n' +
17:13:38 'Date: Thu, 14 Apr 2022 16:13:37 GMT\r\n' +
17:13:38 'Connection: close\r\n' +
17:13:38 'Transfer-Encoding: chunked\r\n' +
17:13:38 '\r\n' +
17:13:38 '0\r\n' +
17:13:38 '\r\n',
17:13:38 expected: '',
17:13:38 operator: 'strictEqual'
17:13:38 }
17:13:38 
17:13:38 Node.js v18.0.0-pre
17:13:38 ...

Build links

• https://ci.nodejs.org/job/node-test-commit-freebsd/43657/
• https://ci.nodejs.org/job/node-test-commit-osx/44529/

Additional information

Test was recently updated by #41263.

cc @ShogunPanda

[ShogunPanda]

I will take care of that tomorrow morning.

Out of the box I just have to fine tune timers.

@nodejs/build Can I get access to that BSD machine?

[tniessen]

Looks like #42846 reduced the error rate by some amount but it's still flaky. We can probably further increase the base timeout and see if that helps, even if the test will become unbearably slow.

[ShogunPanda]

I have a further change in #42812 which should reduce it even more.
I'd suggest to wait for that to land and see what happens.

Anyway given the success rate is above 99% I think we might think about closing this (since retries in CI are normal) and reopen only if there is consistent failure.

[richardlau]

I have a further change in #42812 which should reduce it even more. I'd suggest to wait for that to land and see what happens.

Anyway given the success rate is above 99% I think we might think about closing this (since retries in CI are normal) and reopen only if there is consistent failure.

This issue is tracking that the test is flaky, which it still appears to be so I'm reopening.

[tniessen]

It's interesting that it seems to only happen on macOS and FreeBSD. I might run a few stress tests.

[tniessen]

Patch (assuming the issue is timing-related):

diff --git a/test/parallel/test-http-server-headers-timeout-keepalive.js b/test/parallel/test-http-server-headers-timeout-keepalive.js
index 05531087ed83..ba82cb0e0c9c 100644
--- a/test/parallel/test-http-server-headers-timeout-keepalive.js
+++ b/test/parallel/test-http-server-headers-timeout-keepalive.js
@@ -24,7 +24,7 @@ function performRequestWithDelay(client, firstDelay, secondDelay, closeAfter){
 }, firstDelay + secondDelay).unref();
 }
 
-const headersTimeout = common.platformTimeout(2000);
+const headersTimeout = common.platformTimeout(5000);
 const server = createServer({
 headersTimeout,
 requestTimeout: 0,
diff --git a/test/parallel/test-http-server-request-timeout-keepalive.js b/test/parallel/test-http-server-request-timeout-keepalive.js
index 2466e1ee7a95..eb6d64b2f2bb 100644
--- a/test/parallel/test-http-server-request-timeout-keepalive.js
+++ b/test/parallel/test-http-server-request-timeout-keepalive.js
@@ -24,7 +24,7 @@ function performRequestWithDelay(client, firstDelay, secondDelay, closeAfter){
 }, firstDelay + secondDelay).unref();
 }
 
-const requestTimeout = common.platformTimeout(2000);
+const requestTimeout = common.platformTimeout(5000);
 const server = createServer({
 headersTimeout: 0,
 requestTimeout,

First run (master and with patch):

	osx11	freebsd12-x64
master	OK: 902 NOT OK: 98 TOTAL: 1000	OK: 863 NOT OK: 137 TOTAL: 1000
increased timeout	OK: 676 NOT OK: 324 TOTAL: 1000	OK: 1000 NOT OK: 0 TOTAL: 1000

Second run (master and with patch):

	osx11	freebsd12-x64
master	OK: 910 NOT OK: 90 TOTAL: 1000	OK: 819 NOT OK: 181 TOTAL: 1000
increased timeout	OK: 713 NOT OK: 287 TOTAL: 1000	OK: 1000 NOT OK: 0 TOTAL: 1000

Unless I'm mistaken, increasing the timeout fixes the issues on FreeBSD but somehow makes it worse on macOS?

I started a third run with fresh revisions because I find this hard to believe (master and with patch).

Update: Third run (master and with patch):

	osx11	freebsd12-x64
master	OK: 916 NOT OK: 84 TOTAL: 1000	OK: 838 NOT OK: 162 TOTAL: 1000
increased timeout	OK: 721 NOT OK: 279 TOTAL: 1000	OK: 1000 NOT OK: 0 TOTAL: 1000