[logviewer] missing contents from large logs

[mostynb]

I ran some fairly long-running builds on a test buildbot 0.9.6 instance, which create > 24000 log lines. Once the build is done, I scrolled around the logs and noticed that there are blank patches of missing lines. Copy+pasting across the blank patches simply skips from the first line before the blank patch to the first line after it.

Tested with linux 64 bit chrome 58.0.3029.81.

[tardyp]

The logs are fetched from the master on demand. Are you sure this is not because they have not yet finished loading?
Do you have any errors in the browser console/ twisted.log?

[mostynb]

Chrome appears to have finished loading the page ok. Devtools shows a few of these warnings:
Should not use collection as a promise. Callback will be called several times! scripts.js:18

There are also some "Timing out client: IPv4Address(TCP, '... lines in twisted.log, which appear when I'm scrolling around the logs looking for the missing parts (it takes a little while to find the missing parts due to the size of the logs).

[mostynb]

Here's an example:

And when I scrolled up a little, the blank patch moved up a bit, and a few of the missing log lines were filled in:

[tardyp]

Timing out client: IPv4Address is related to crossbario/autobahn-python#829 . It is actually not a real issue, just an annoying timeout from twisted, which is triggered by modern browser's keep-alive http connections

For me, what you are describing is the normal behaviour. It happens if the network is a bit flaky.
It should fix if you wait a little bit more.
If you open the browser debug pane, you should see there are pending requests until the log views are eventually loaded.

[mostynb]

This occurs on my LAN, no other network flakiness or dropped packets as far as I know, but I will double check tomorrow.

[mostynb]

I had to clean my test setup, so unfortunately I can't just reload the page and check devtools.