run on ubuntu14.04 , cpu 100%

[pinghe]

step:

1: sudo apt-get install graphviz graphviz-dev libgv-ruby
2:

{{graphviz_link()
   digraph G {
      server1 -> server2;
   }
}}

[tckz]

1. How about log?

   e.g.)

   grep wiki_graphviz path/to/log/production.log
   

   Note: You should specify the log path/filename that matches your running environment. Perhaps production.log or development.log

2. Could you try use dot command instead of libgv-ruby ?

   If gv(name of ruby lib) is not found in your redmine environment, the plugin executes dot command.

[pinghe]

log:

[wiki_graphviz]not in cache: wiki_graphviz_plugin.7c37dc35f6c7ba77a7a647a15c7acf23aafeea7344b715c37913d0bb1fc6c53e
[wiki_graphviz]using Gv
[wiki_graphviz]child status: #<Process::Status: pid 26335 exit 5>
[wiki_graphviz]using dot

top command：
dot process continued occupation of CPU 99.9%

[tckz]

In my environment(CentOS7.1 x64/ruby 2.2/graphviz 2.30.1/redmine 3.1.2),
It did not reproduce this issue which you reported.

Could you try to check graphviz(dot) behavior?

1. Save the dot text to a file.

   digraph G {
   server1 -> server2;
   }
   

2. Run dot command like below.

   $ /path/to/dot -Kdot -Tpng < /path/to/saved.dot > /path/to/out.png
   

   NOTE: Redirection must be used.

I think it seems to relate to the issue below.
http://www.graphviz.org/mantisbt/view.php?id=2543

[pinghe]

graphviz(dot) behavior is correct.

Package: graphviz
Architecture: amd64
Version: 2.36.0-0ubuntu3

[pinghe]

run on sudo is correct.

system("sudo dot -K#{layout} -T#{fmt[:type]} < \"#{temps[:dot].path}\" > \"#{temps[:img].path}\"  2>\"#{temps[:err].path}\"")