Start render always 0 with private instance + nodejs + chrome + fedora

Support
1

hi,

On testing with my private instance with both server & nodejs agent (& also the chrome) running on the same Fedora 17 linux box (32 bit), I am seeing that the start render is always 0 for all the tests.

I am able to observe all other times/metrics displayed correctly except that the start render is always 0.

I browsed through lots of other posts regarding this problem but not able to resolve my problem. Any advice is much appreciated.

I got the source code/executables from here.

Regards
Ram

2

The nodejs desktop agent doesn’t capture video so most of the render metrics won’t work. There should be a “StartRenderDT” metric which uses the first paint event in the timeline but it’s not as accurate as the video-based measurements.

3

hi Patrick,

Thanks for the update.

As you said, there was a “_renderDT” field in the har output when I ran webpagetest locally sometime back (1 month) by fetching & using the top of repo code at that time.

But, on fetching & using the webpagetest code from top of repo of last week, I am not seeing this field???

Please shed some light.

har o/p for the tests are given below…

[size=x-small][quote]Older har o/p:
“pages”: [
{
“startedDateTime”: “1970-01-01T00:00:00.000+00:00”,
“title”: “Run 1, First View for http://www.cnn.com/”,
“id”: “page_1_0”,
“pageTimings”: {
“onLoad”: 10264,
“onContentLoad”: -1,
“_startRender”: 0
},
“_loadTime”: 10264,
“_docTime”: 10264,
“_fullyLoaded”: 10975,
“_bytesOut”: 29632,
“_bytesOutDoc”: 27941,
“_bytesIn”: 1484133,
“_bytesInDoc”: 1392090,
“_requests”: 158,
“_requestsDoc”: 148,
“_responses_200”: 146,
“_responses_404”: 0,
“_responses_other”: 12,
“_result”: 0,
“_testStartOffset”: 0,
“_cached”: 0,
“_optimization_checked”: 0,
“_start_epoch”: 1392218081.3465,
“_URL”: “http://www.cnn.com/”,
“_TTFB”: 1001,
“_connections”: 55,
“_SpeedIndexDT”: 2195,
“_SpeedIndex”: 2195,
“_VisuallyCompleteDT”: 11205,
“_renderDT”: 34,
“_effectiveBps”: 148800,
“_effectiveBpsDoc”: 150285,
“_render”: 0,
“_domTime”: 0,
“_aft”: 0,
“_titleTime”: 0,
“_loadEventStart”: 0,
“_loadEventEnd”: 0,
“_domContentLoadedEventStart”: 0,
“_domContentLoadedEventEnd”: 0,
“_lastVisualChange”: 0,
“_server_rtt”: 0,
“_firstPaint”: 0
}
],

Newer har o/p:
“pages”: [
{
“startedDateTime”: “1970-01-01T00:00:00.000+00:00”,
“title”: “Run 1, First View for http://www.news.google.co.in/”,
“id”: “page_1_0”,
“pageTimings”: {
“onLoad”: 10808,
“onContentLoad”: -1,
“_startRender”: 0
},
“_loadTime”: 10808,
“_docTime”: 10808,
“_fullyLoaded”: 21964,
“_bytesOut”: 11495,
“_bytesOutDoc”: 2680,
“_bytesIn”: 1118720,
“_bytesInDoc”: 650502,
“_requests”: 76,
“_requestsDoc”: 18,
“_responses_200”: 73,
“_responses_404”: 0,
“_responses_other”: 3,
“_result”: 0,
“_testStartOffset”: 0,
“_cached”: 0,
“_optimization_checked”: 0,
“_start_epoch”: 1393497259.5214,
“_URL”: “http://www.news.google.co.in/”,
“_TTFB”: 363,
“_connections”: 33,
“_effectiveBps”: 51790,
“_effectiveBpsDoc”: 62278,
“_render”: 0,
“_domTime”: 0,
“_aft”: 0,
“_titleTime”: 0,
“_loadEventStart”: 0,
“_loadEventEnd”: 0,
“_domContentLoadedEventStart”: 0,
“_domContentLoadedEventEnd”: 0,
“_lastVisualChange”: 0,
“_server_rtt”: 0,
“_firstPaint”: 0
},[/quote]
[/size]

Regards
Ram

4

You won’t see it unless you enable timeline capture from Chrome. Previously we used to fake the dev tools events for IE and Firefox but we stopped doing that.

5

Hi Patrick,
Thanks for the clarification.
Is there any future plans to support linux test agent based on firefox (or any browser other than chrome) for a private instance server running on linux box?
Please let me know.
Regards
Ram

6

No. At least none that we are working on because the market share just doesn’t justify it (even if it makes testing easier). Mobile is getting most of the development attention at the moment. I could see Chrome Books/boxes getting some attention if they keep gaining popularity but Linux as a generic desktop is as close to zero as it gets.

7

Hi Patrick,

Thanks for sharing the info.

I would like to appreciate your efforts to respond to the queries posted by me.
As you have resolved the issue that I was facing, we can consider this thread as closed.
Thanks for your time.

Regards
Ram