v3.5 error - control socket has closed unexpectedly

[bcronje]

Context

I use iperf3 as part of an automated test environment using ansible. We run various tests over different network conditions.

• Version of iperf3: iperf 3.5 (cJSON 1.5.2)

• Hardware: lxd containers

• Operating system (and distribution, if any): Ubuntu 16.04.3

• Other relevant information (for example, non-default compilers,
  libraries, cross-compiling, etc.):

Bug Report

Randomly I get the following error in the json report:
"error": "error - control socket has closed unexpectedly"
When it happens, it seems to always occur after the second last interval, e.g. using -t 60 the json report will contain the interval report for interval 58 - 59, and then ends with the error. So the 60th interval is never reported on.

The server is run with iperf3 -s -D
The client is run with iperf3 -c 1.1.1.1 -t 60 -P 8 -J

Unfortunately I do not have access to the output of the server.

Note - I never experienced this when I was still using iper3 version that ships with Ubuntu, think it was v3.1.x ?? This might only be coincidence or a regression.

• Expected Behavior
  Expects to complete the test without any errors.

• Actual Behavior
  Test ends with "error": "error - control socket has closed unexpectedly"

• Steps to Reproduce
  It occurs randomly, so not easy to reproduce.

[bmah888]

Increased the timeout on the control channel as per the first commit in PR #859, which hopefully will solve this issue.

A further enhancement could be to allow setting this as a command-line parameter, although note that the timer that is affected by this has no effect for the --bytes or --blockcount cases.

Closing.