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Starred by 6 users

Issue metadata

Status: Duplicate
Merged: issue 275955
Owner: ----
Closed: Feb 2014
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 2
Type: Bug

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Blank tab when loading many tabs from the same domain with EventSource

Reported by, Jul 30 2012 Back to list

Issue description

Chrome Version: 18.0.1025.168 (Build de développement 134367 Linux) Ubuntu 12.04
Other browsers tested:
     Safari 5: Fail
  Firefox 4.x: Fail
       IE 7/8/9: no EventSource support

What steps will reproduce the problem?
1. I've opened 10 tabs on the same site (same domain) and didn't close them. This web site use EventSource on each page.

What is the expected result?

At least, having an error message, not just a blank page.

Ideally, the browser should have not allowed the EventSource to take all the connections and could load the page.

What happens instead?

The first 6 tabs are opened correctly. The 4 next show a blank page with 'Connecting...' as a title and a loader. And nothing else happened until I closed one tab, not even a timeout after several minutes.

Please provide any additional information below.

The browser used one connection for each EventSource on the 6 first tabs and hit a limit.

See and

Comment 1 by, Nov 26 2012

We ran into this bug at - each instance of our webmail created a new EventSource connection. The issue is that Chromium only allows a maximum of 6 concurrent connections to the same origin, no matter how many tabs are open at that domain. Since EventSource connections are permanent, opening 6 tabs takes all available connections, so no further data can be accessed from the site, as all future connections are blocked, waiting for the EventSource connections to finish.

I think EventSource connections should not be counted towards the maximum concurrent connections. Alternatively, this limit should scale with the number of tabs open at the same origin.
We ran across this problem recently and had to use a hacky workaround.

I believe the real solution is that EventSource connections should not count towards the total number of connections to a particular domain.

What's particularly annoying is how bad the failure mode is of this. The browser just sits there spinning doing nothing because it believe it's run out of connections to that domain waiting for one to become free, but because they're EventSource connections, by definition they're long term and never become free. This gives users the impression they're something wrong with the website, when it's actually a problem with the browser.
Project Member

Comment 3 by, Mar 10 2013

Labels: -Area-Undefined
Mergedinto: 275955
Status: Duplicate
 Issue 133099  has been merged into this issue.

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