From da1dbd2093ec040f05f4daf9fc8ca28dc8262ec8 Mon Sep 17 00:00:00 2001 From: Tonis Tiigi Date: Mon, 9 May 2016 10:40:11 -0700 Subject: [PATCH] docs: clarify docker attach Signed-off-by: Tonis Tiigi --- docs/reference/commandline/attach.md | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/docs/reference/commandline/attach.md b/docs/reference/commandline/attach.md index dfe2908c3b..b28b6fc263 100644 --- a/docs/reference/commandline/attach.md +++ b/docs/reference/commandline/attach.md @@ -39,6 +39,15 @@ using `CTRL-p CTRL-q` key sequence. It is forbidden to redirect the standard input of a `docker attach` command while attaching to a tty-enabled container (i.e.: launched with `-t`). +While a client is connected to container's stdio using `docker attach`, Docker +uses a ~1MB memory buffer to maximize the throughput of the application. If +this buffer is filled, the speed of the API connection will start to have an +effect on the process output writing speed. This is similar to other +applications like SSH. Because of this, it is not recommended to run +performance critical applications that generate a lot of output in the +foreground over a slow client connection. Instead, users should use the +`docker logs` command to get access to the logs. + ## Override the detach sequence