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https://issues.apache.org/jira/browse/HTRACE-301?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Colin Patrick McCabe reassigned HTRACE-301:
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    Assignee: Colin Patrick McCabe  (was: Masatake Iwasaki)

> htraced: fix unit tests that aren't waiting for spans to be written, use 
> semaphore for WrittenSpans
> ---------------------------------------------------------------------------------------------------
>
>                 Key: HTRACE-301
>                 URL: https://issues.apache.org/jira/browse/HTRACE-301
>             Project: HTrace
>          Issue Type: Bug
>          Components: htraced
>            Reporter: Masatake Iwasaki
>            Assignee: Colin Patrick McCabe
>            Priority: Minor
>         Attachments: HTRACE-301.001.patch
>
>
> We have a few unit tests that aren't waiting for spans to be written, but 
> which should.  For example, TestClientOperations intermittently fails due to 
> missing spans. According to the test log, FindSpan was called before the span 
> is written to datastore.
> This patch replaces WriteSpans with a semaphore.  The reasoning is that it is 
> sometimes difficult to debug unit tets where the datastore is blocked sending 
> to the WriteSpans debug channel because the test has become blocked or is 
> exiting.  Buffered channels could eliminate this problem, but for certain 
> tests, the buffers would have to be extremely large.  Using a semaphore 
> eliminates this problem.  Semaphores will also be more efficient when we 
> start ingesting spans in batches (see HTRACE-298) since we can increment the 
> semaphore once rather than sending multiple spans on the WriteSpans channel.  
> This is important for getting realistic benchmarks.



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