[jira] [Commented] (HTRACE-275) Add NullTracer which never creates a trace span

["Colin Patrick McCabe (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HTRACE-275?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14940641#comment-14940641 ] 

Colin Patrick McCabe commented on HTRACE-275:
---------------------------------------------

A few notable things:
* We implement this via a subclass, but we don't make the subclass public (in case we want to switch to a different implementation later)
* Can't "pull the rug out" from another thread by closing {{NullTracer}}... its close method does nothing.
* Can't add {{Sampler}} objects to {{NullTracer}}
* {{NullTracer}} is in its own {{SamplerPool}} to avoid causing issues for applications that iterate over the main sampler pool (like Hadoop once we add the ability to modify samplers via RPC)

> Add NullTracer which never creates a trace span
> -----------------------------------------------
>
>                 Key: HTRACE-275
>                 URL: https://issues.apache.org/jira/browse/HTRACE-275
>             Project: HTrace
>          Issue Type: Improvement
>          Components: api
>            Reporter: Colin Patrick McCabe
>            Assignee: Colin Patrick McCabe
>         Attachments: HTRACE-275.001.patch
>
>
> [~iwasakims] suggested adding a {{NullTracer}} which never creates a trace span.  This would be more convenient than checking tracer objects against null in some cases.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)