Careful what conclusions you draw from this post. The comments have further discussion which are very relevant: > Edward Muller says: 1 October, 2013 at 20:2

Careful what conclusions you draw from this post. The comments have further discussion which are very relevant: > Edward Muller says: 1 October, 2013 at 20:29 Was/Is this app located in the EU region? If so, we recently (yesterday 2013/9/30) fixed a problem where each log line would result in a separate, almost synchronous post to logplex. This problem should now be solved. > Michel (ed: Blog Author) says: 21 October, 2013 at 10:33 @Edward and Fred: the app is indeed running in the EU region. I haven’t gotten around seeing if the performance has improved (the app in question was very ephemeral to begin with), but I’m glad this helped you close in on this issue! Also, another commenter tested the blocking vs. non-blocking property of stdout and found the default is "pipe" on Heroku [1]. So the most simple conclusion is that this was a problem affecting Heroku logging in the EU region that was identified and resolved back in 2013. 1. http://micheljansen.org/blog/entry/1698#comment-522151 http://micheljansen.org/blog/entry/1698#comment-522151