RFR 8184445: JShell tests: fail intermittently if tests are run in high concurrent mode.

[joe darcy]

Hi Robert,

On 2/26/2018 10:57 AM, Robert Field wrote:
>
>
> On 02/26/18 10:23, joe darcy wrote:
>> Hi Robert,
>>
>> The fix looks acceptable in terms of addressing the problem, but is 
>> there a sense of how this might impact running time of the test suite?
>>
>> Phrased differently, are there plans to make the tests more robust to 
>> concurrent runs in the future?
>
> Hi Joe,
>
> There is a lot of network connection happening in these tests, most of 
> which is in layers we don't control (JDI).  We have been trying to 
> lower the risk and we don't see failures running the tests ourselves, 
> but intermittent failures scattered through the suite during testing 
> (e.g. mach5) have been a constant problem.
>
> We will see the impact on test duration.  Default connection has 
> three-level fail-over, the tests of other connection modes see failure 
> far more frequently, so, if necessary, we can look at tuning this.
>

 From some quick checking, there are about 80 tests in that directory. 
 From one sample point on my laptop, the tests took a good long while to 
run. If some of the tests can be reliably run concurrently, I'd much 
prefer to see a subset of tests moved to a sheltered directory.

Thanks,

-Joe