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Too agressive caching

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Betelgeuse

17 Jul, 2009 05:22 AM

Lighthouse puts pages to cache too aggressively. I regularly see outdated information in milestones or tickets and have to hit F5 to get updated information. Even the support page did not show me as logged in until I hit ctrl+r after logging in.

1. 1 Posted by Rick on 17 Jul, 2009 04:15 PM

   

   I've never seen issues like this. Are you sure you're not accessing Lighthouse through some kind of firewall or proxy that's caching it? This is a common scenario for users behind a corporate firewall.

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2. 2 Posted by Betelgeuse on 19 Jul, 2009 09:17 AM

   

   Cache servers shouldn't cache things if Expires/Cache-Control headers are set properly to tell that pages shouldn't be cached.

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3. 3 Posted by Rick on 19 Jul, 2009 10:46 AM

   

   Lighthouse doesn't do anything special with caching headers.
   Cache-control is set to private, max-age is 0, and the etag changes on
   every request. Honestly, we should probably do more, but SSL requests
   aren't even cached for security reasons anyway.

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4. 4 Posted by Betelgeuse on 19 Jul, 2009 11:16 AM

   

   I am using a free plan for a small project so there's no SSL. It could of course be some misbehaving HTTP 1.0 cache in the middle but besides HTTP caching if you are using caching on the server side internally it could be that kind of thing too but of course you know your architecture way better than I ever can see from the outside. If I stumble upon on it again I can take a closer look with Firebug to see what's going on. Basically the situation involved an another using adding new tickets and me browsing on other pages and the total on the right hand side was not updating.

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5. 5 Posted by Betelgeuse on 20 Jul, 2009 01:40 PM

   

   Saw this again when submitting a new ticket the totals on the right were not updated before hitting F5. I know this machine is not behind any proxies.

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6. 6 Posted by Rick on 20 Jul, 2009 02:15 PM

   

   Ah, thanks for being more specific on what wasn't changing. Those
   totals can take a while to update (depending on the number of your
   tickets and saved searches), so it happens in the background. I have
   some ideas now that could help, but I haven't had time to investigate
   them.

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7. 7 Posted by Betelgeuse on 24 Jul, 2009 08:36 PM

   

   Just to note one other spot where I spotted this is listing of tickets for milestones. It's not really nice to always having to refresh to see what's left for a milestone.

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8. 8 Posted by Rick on 24 Jul, 2009 08:40 PM

   

   I don't understand... you click on a milestone, and then have to force
   a browser refresh to see the update? That shouldn't happen -- we
   don't even use any browser caching headers since most of the content
   is user-specific and private. I've never seen this, and we work
   heavily with milestones. Of course if you or someone updates the
   tickets in another browser window, you have to refresh to see the
   changes. Is _that_ what you're talking about?

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9. 9 Posted by Betelgeuse on 24 Jul, 2009 08:47 PM

   

   I do some changes that I know should have an effect on the listing of tickets and when I go to listing via link there's an outdated version of the page.

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10. 10 Posted by Rick on 24 Jul, 2009 08:51 PM

    

    Sometimes it can take a few minutes to update that stuff, depending on
    what Lighthouse is doing at the time. However, I just tried resolving
    a ticket, and it was immediately removed when I clicked to the
    milestone. I'm just not seeing any caching issues.

    Do you have any means of capturing the HTTP request data from your
    browser? I'd like to see if it's even attempting to re-fetch the
    page.

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11. 11 Posted by Betelgeuse on 25 Jul, 2009 05:12 AM

    

    I do have firebug but I don't want to use my project for testing purposes. Do you have a sandbox to test with?

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12. 12 Posted by Betelgeuse on 27 Jul, 2009 11:17 AM

    

    I resolved a ticket and went to the milestone listing and the resolved ticket was there. This is what I get from FF about:cache:

    Key: <url>
    Data size: 5676 bytes
    Fetch count: 9
    Last modified: 2009-07-27 14:10:14
    Expires: 1970-01-01 02:00:00
    

    Firebug says it's not reloading the page which is quite weird as it should have expired already. The only request it does is for google analytics.

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13. 13 Posted by Betelgeuse on 27 Jul, 2009 11:22 AM

    

    Interestingly I also need to reload the page of this discussion to see me new comments.

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