testcafe: TestCafe hangs on loading page and freezes execution when executing concurrently

To provide an update: We tried a number of things and finally had some progress by running tests via testcafe runner in groups. We had the same situation as @alienintheheights mentioned - 200+ tests and it was hanging in random places without any logs. We split the tests in two almost equal size groups and they still hang from time to time but not so often - say 1-2 in 20, while before it was 9 hangs from 10 runs. It’s not ideal but at least it doesn’t fully block our work. We are yet to experiment splitting the tests in more groups. Hope this helps.

Also running into this. Our tests consistently hang, though the point at which they do varies (we have around 300 tests that run nightly). No concurrency. Running latest, 2.6.1, on node 16.13.2.

When it gets stuck, strace on the /node_modules/.bin/testcafe process shows this over and over:

 strace -f -tt -s 200 -p 6490
strace: Process 6490 attached with 7 threads
[pid  6496] 14:20:07.310527 futex(0x65b99ec, FUTEX_WAIT_PRIVATE, 1, NULL <unfinished ...>
[pid  6495] 14:20:07.310672 futex(0x64c089c, FUTEX_WAIT_PRIVATE, 4, NULL <unfinished ...>
[pid  6494] 14:20:07.310705 futex(0x64c089c, FUTEX_WAIT_PRIVATE, 4, NULL <unfinished ...>
[pid  6493] 14:20:07.310734 futex(0x64c089c, FUTEX_WAIT_PRIVATE, 4, NULL <unfinished ...>
[pid  6492] 14:20:07.310762 futex(0x64c089c, FUTEX_WAIT_PRIVATE, 4, NULL <unfinished ...>
[pid  6491] 14:20:07.310789 epoll_wait(9,  <unfinished ...>
[pid  6490] 14:20:07.358401 epoll_wait(13,

Those pids correspond to defunct instances of Google chrome. New ones have been spawned in its place.

www   6542     1  0 13:09 ?        00:00:00 /opt/google/chrome/chrome_crashpad_handler --monitor-self-annotation=ptype=crashpad-handle
www   6547  6535  0 13:09 pts/0    00:00:00 /opt/google/chrome/chrome --type=zygote --no-zygote-sandbox --headless --headless --crashp
www  6549  6535  0 13:09 pts/0    00:00:00 /opt/google/chrome/chrome --type=zygote --headless --headless --crashpad-handler-pid=6542
www   6552  6549  0 13:09 pts/0    00:00:00 /opt/google/chrome/chrome --type=zygote --headless --headless --crashpad-handler-pid=6542
www   6570  6535  2 13:09 pts/0    00:02:09 /opt/google/chrome/chrome --type=utility --utility-sub-type=network.mojom.NetworkService -
www   6573  6552 49 13:09 pts/0    00:37:17 /opt/google/chrome/chrome --type=renderer --headless --crashpad-handler-pid=6542 --first-r
www   6606  6547  2 13:09 pts/0    00:01:30 /opt/google/chrome/chrome --type=gpu-process --headless --ozone-platform=headless --use-an
www   6607  6606  0 13:09 pts/0    00:00:00 /opt/google/chrome/chrome --type=broker

Meanwhile the node_modules/testcafe/lib/cli process is looping the following POST to /messaging

[pid  6497] 14:21:33.576119 epoll_wait(14, [], 1024, 0) = 0
[pid  6497] 14:21:33.576213 epoll_wait(14, [], 1024, 425) = 0
[pid  6497] 14:21:34.001847 epoll_wait(14, [], 1024, 0) = 0
[pid  6497] 14:21:34.001935 epoll_wait(14, [{EPOLLIN, {u32=27, u64=27}}], 1024, 1976) = 1
[pid  6497] 14:21:34.084023 read(27, "POST /messaging HTTP/1.1\r\nHost: 192.168.2.100:41539\r\nConnection: keep-alive\r\nContent-Length: 230\r\ncache-control: no-cache, no-store, must-revalidate\r\nUser-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleW"..., 65536) = 688
[pid  6497] 14:21:34.085589 writev(27, [{iov_base="HTTP/1.1 200 OK\r\ncontent-type: application/json\r\ncache-control: no-cache, no-store, must-revalidate\r\npragma: no-cache\r\nDate: Thu, 01 Jun 2023 19:21:34 GMT\r\nConnection: keep-alive\r\nKeep-Alive: timeout="..., iov_len=1511}, {iov_base="", iov_len=0}], 2) = 1511

Don’t know if that helps. We had the same outcome on older versions too.

This is our .testcaferc.json

{
   
    "browsers": ["chrome:headless"],
    "src": ["test/*-test.js"],

    "speed": 1,
    "selectorTimeout": 30000,
    "assertionTimeout": 30000,
    "pageLoadTimeout": 60000,
    "ajaxRequestTimeout": 300000,
    "testExecutionTimeout": 300000,
    "nativeAutomation": false,

    "quarantineMode": false,
    "debugMode": false,
    "debugOnFail": false,
    "stopOnFirstFail": false,
    "skipJsErrors": true,
    "skipUncaughtErrors": true,
    "disablePageCaching": true,
    "developmentMode": false,
    
    "reporter": [
        {
            "name": "spec"
        },
        {
            "name": "xunit",
            "output": "test/output/reports/report.xml"
        },
        {
            "name": "html",
            "output": "test/output/reports/report.html" 
        }
    ],

    "screenshots": {
        "path": "test/output/screenshots",
        "takeOnFails": true,
        "pathPattern": "${DATE}_${TIME}/${FIXTURE}/test-${TEST_INDEX}/${FILE_INDEX}.png"
    }

   
}

Hi - we are seeing similar problem on firefox and without concurrency, too.