Google bot delays executing JavaScript for days (opens in new tab)

(itbrokeand.ifixit.com)

128 pointsdbeardsl13y ago37 comments

37 comments

h2s13y ago

    > If you're removing code or changing an endpoint,
    > be careful you don't screw the Google bot, which
    > might be "viewing" 3-day-old pages on your
    > altered backend.

An interesting proposition. Personally, unless I was operating in some sector where keeping Googlebot happy was key to staying competitive and there was solid evidence it could hurt my page rank, I don't think I'd be prepared to go to this length. Google is doing quite an atypical thing here compared to regular browsers and I'd like to think Google engineers are smart enough to account for this type of thing in the early stages of planning.

They have a difficult cache invalidation problem here. The only way to find out if the Javascript in use on a site has changed is by checking if the page HTML has changed. And on top of that, the Javascript can change without any noticeable change to the HTML.

zaptheimpaler13y ago

obligatory: "There are only two hard problems in Computer Science: cache invalidation, naming things, and off-by-one errors."

ashray13y ago

Googlebot also does some other crazy stuff. Like looking at url patterns and then trying out variations.. they're almost trying to sniff URLs!

For example if I have a page: www.domain.com/xyz/123

Googlebot (without any links to other pages, will actually try URLs like) www.domain.com/xyz/1234 www.domain.com/xyz/122 www.domain.com/xyz/121 and so on...

It's crazy how much 'looking around' they do these days!

ceejayoz13y ago

I believe that one's mostly a search for duplicate content - looking for URL parameters that don't make a difference.

eli13y ago

I'm not too surprised. I've got Googlebot still requesting old URLs even through there are no incoming links to them (that I know of) and they've been either 404 or 301 redirected for six months. I even tried using 410 Gone instead of 404, but it made no difference.

chrislomax13y ago

To just reiterate this further, I am still 301'ing urls that have been dead for nearly 5 years. I still get requests in for them. I don't want to 404 them in fear of losing that slight bit of traffic so I just 301 them. I am really surprised they don't remove these urls from their cache and I can't think for the life of me why they don't?

gizmo68613y ago

They might have some obscure incoming url from somewhere else on the net.

1 more reply

udfalkso13y ago

Same here.

jes519913y ago

Your users may be, too. It's not unusual for me to open my sleeping laptop several days later and expect the open web pages to work without refreshing them.

oakwhiz13y ago

What might be a good idea for Javascript-heavy web apps is to make an Ajax call to the server to see if a refresh of the page is required.

jacobolus13y ago

Please don’t even call out to the server, unless I actively interact with the page. I sometimes open 50 or 60 browser tabs at once, and when I unsleep my laptop or connect to a new wifi hotspot, many of them try to simultaneously make such ajax calls, which prevents any other web pages I want to open from loading until those calls either make it through or time out. Occasionally I have to SIGSTOP my main browser and open a different one if I need to access something online right away. Even pages of ostensibly static content, like years-old news articles, now are littered with "web 2.0" doodads on them which do this kind of crap.

1 more reply

moreati13y ago

Please don't do that. I left that tab open on purpose, I'm half way through reading the page - if the page refreshes I likely lose my position

2 more replies

xiongchiamiov13y ago

It's a call that was being made (only) when the page loaded.

TazeTSchnitzel13y ago

I wonder if it is Google's visual site previews/thumbnails that you get when you click on the arrow at the side of a search result, that are doing this.

Perhaps Google fetches the crawled page from the cache and then renders that for the previews?

sj2613y ago

This was my first thought, and seems likely. They do several forms of analysis on their cache. It could even be some engineers running tests or queries that require rendering the page or at least bootstrapping the DOM.

georgemcbay13y ago

Is this surprising? I'd expect the possibility of this sort of behavior from any system that was vaguely Map-Reduce-y and operated on the scale of data that Google's indexing does.

ericcholis13y ago

I'm wondering if some of the simpler cache-busting tricks would force google update their cache. For example, somescript.js?v=201210221559.

dbeardslOP13y ago

That's not the issue here, we include the md5 hash of the content in the url of every javascript / css asset. New pages had all the correct (brand new) urls. The issue is that Google is executing javascript on html pages they downloaded days ago. The only solution I can see is to fire off cloudfront cache expiration requests for all old assets. But that negates the simplicity of including the hash of the content in the url.

ChuckMcM13y ago

Is it possible that people are looking at the page from Google's cache? I'm thinking the 3taps kind of 'web site scraping that doesn't look like web site scraping'

2 more replies

lists13y ago

Did anyone else get really bad font rendering running Chrome on Windows 7?

teamonkey13y ago

Yes, it's a known issue and has been a problem for a long time. Quite ironic that it's particularly bad with Google Web Fonts.

http://code.google.com/p/chromium/issues/detail?id=137692

j / k navigate · click thread line to collapse

37 comments

h2s13y ago

    > If you're removing code or changing an endpoint,
    > be careful you don't screw the Google bot, which
    > might be "viewing" 3-day-old pages on your
    > altered backend.

zaptheimpaler13y ago

obligatory: "There are only two hard problems in Computer Science: cache invalidation, naming things, and off-by-one errors."

ashray13y ago

Googlebot also does some other crazy stuff. Like looking at url patterns and then trying out variations.. they're almost trying to sniff URLs!

For example if I have a page: www.domain.com/xyz/123

Googlebot (without any links to other pages, will actually try URLs like) www.domain.com/xyz/1234 www.domain.com/xyz/122 www.domain.com/xyz/121 and so on...

It's crazy how much 'looking around' they do these days!

ceejayoz13y ago

I believe that one's mostly a search for duplicate content - looking for URL parameters that don't make a difference.

eli13y ago

chrislomax13y ago

gizmo68613y ago

They might have some obscure incoming url from somewhere else on the net.

1 more reply

udfalkso13y ago

Same here.

jes519913y ago

Your users may be, too. It's not unusual for me to open my sleeping laptop several days later and expect the open web pages to work without refreshing them.

oakwhiz13y ago

What might be a good idea for Javascript-heavy web apps is to make an Ajax call to the server to see if a refresh of the page is required.

jacobolus13y ago

1 more reply

moreati13y ago

Please don't do that. I left that tab open on purpose, I'm half way through reading the page - if the page refreshes I likely lose my position

2 more replies

xiongchiamiov13y ago

It's a call that was being made (only) when the page loaded.

TazeTSchnitzel13y ago

I wonder if it is Google's visual site previews/thumbnails that you get when you click on the arrow at the side of a search result, that are doing this.

Perhaps Google fetches the crawled page from the cache and then renders that for the previews?

sj2613y ago

georgemcbay13y ago

Is this surprising? I'd expect the possibility of this sort of behavior from any system that was vaguely Map-Reduce-y and operated on the scale of data that Google's indexing does.

ericcholis13y ago

I'm wondering if some of the simpler cache-busting tricks would force google update their cache. For example, somescript.js?v=201210221559.

dbeardslOP13y ago

ChuckMcM13y ago

Is it possible that people are looking at the page from Google's cache? I'm thinking the 3taps kind of 'web site scraping that doesn't look like web site scraping'

2 more replies

lists13y ago

Did anyone else get really bad font rendering running Chrome on Windows 7?

teamonkey13y ago

Yes, it's a known issue and has been a problem for a long time. Quite ironic that it's particularly bad with Google Web Fonts.

http://code.google.com/p/chromium/issues/detail?id=137692

j / k navigate · click thread line to collapse