flush timeoutError in fluentd
<p>I am running <code>fluentd</code> with following config:</p>

<pre><code>&lt;source&gt;
    @type forward
    port 24224
&lt;/source&gt;
&lt;filter docker.**&gt;
    @type concat
    key msg
    stream_identity_key uuid
    multiline_start_regexp /url:/
    multiline_end_regexp /.* ---$/
&lt;/filter&gt;
&lt;match docker.**&gt;
    @type copy
    &lt;store&gt;
        @type stdout
    &lt;/store&gt;
&lt;/match&gt;
</code></pre>

<p>I am getting below <code>Fluent::ConcatFilter::TimeoutError</code> when some <code>event</code> occurs:</p>

<pre><code>2016-05-11 15:22:38 +0530 [warn]: dump an error event: error_class=Fluent::ConcatFilter::TimeoutError error="Timeout flush: docker.containers:67deabd67c04199d" tag="docker.containers" time=1462960358 record={"msg"=&gt;"url: /get/image.jpg\nid: 83110292-24a4-62a8-c155-ebc0f9bbb976"}
2016-05-11 15:22:38 +0530 [info]: Timeout flush: docker.containers:67deabd67c04199d
</code></pre>

<p>Could anyone please tell me why this error is coming and how to resolve it</p>

<p>Thanks</p>