Takuro Ashie

It's a revised patch of #129.

The patch can be simplified by using `Thread::Mutex#owned?` but I don't use it because it's breaks CI on Ruby 1.9.3.

td-agent 1.9.0 or 1.9.2 seems too old, probably you mean td-agent 3.6.0 with fluentd-1.9.2. (td-agent --version shows fluentd's version instead of td-agent package's version). I confirmed this issue with td-agent...

A workaround for it is that adding /opt/td-agent/embedded/bin to your `PATH`: ``` sudo PATH=/opt/td-agent/embedded/bin:$PATH /opt/td-agent/embedded/lib/ruby/gems/2.4.0/bin/fluentd-ui start ```

> The cause is that shebang of /opt/td-agent/embedded/lib/ruby/gems/2.4.0/gems/fluentd-ui-1.2.1/bin/fluentd-ui (which is the actual path of the executable) is inappropriate for td-agent: > > ``` > #!/usr/bin/env ruby > ``` The detail...

Hmm, probably we need to modify fluentd core to realize it.

It seems caused at https://github.com/fluent/fluent-plugin-kafka/blob/eb740212711b1ca1b01089f3feb4e71f2deca381/lib/fluent/plugin/out_rdkafka2.rb#L328-L331 https://github.com/fluent/fluent-plugin-kafka/blob/eb740212711b1ca1b01089f3feb4e71f2deca381/lib/fluent/plugin/out_rdkafka2.rb#L341-L344 rdkafa v0.12.0 seems including incompatible change against above code, `Rdkafka::Producer` no longer has `@polling_thread`. https://github.com/fluent/fluent-plugin-kafka/blob/eb740212711b1ca1b01089f3feb4e71f2deca381/lib/fluent/plugin/out_rdkafka2.rb#L14-L19 Are you using rdkafka v0.12.0?

Are you using td-agent 4.4.0? If so, bundle rdkafka is v0.11.1 and the above change isn't included yet, so that the cause of your problem isn't concerned with rdkafka v0.12.0's...

> we have installed fluentd gem 1.15.1 and rdkafka is 0.12.0 Thanks. Please downgrade to 0.11.x or former.

At first, I don't recommend to use it on Windows, probably it's not so tested on Windows. I’ve never tested it with td-agent 3.x or before but now I've tried...