[SUREFIRE-1548] Parallel Test Execution, ramp up time

**[Mattias Malmgren](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=mattiasmgn)** opened **[SUREFIRE-1548](https://issues.apache.org/jira/browse/SUREFIRE-1548?redirect=false)** and commented

Parallel Test Execution forkCount controls the number of threads being used.
Would it be possible to start the threads with a delay between each test being started,
much like Apache Jmeter works?
We want to run multiple tests in parallel, but when 100 tests start at the very same time it puts a lot of load on the system under test. If we could start each test with a delay between the tests, then it would not stress our application so hard.

EG to delay each test started with 10 seconds:

> ``
> \org.apache.maven.plugins\
>   \maven-failsafe-plugin\
>   \2.19.1\
>   \
>   \
>   \acceptance-test\
>   \integration-test\
>   \
>   \integration-test\
>   \
>   \
>   \100\
> `*10s*`
>
>  \true\
>   \
>   \**/*IT.class\
>   \
>   \
> \
> ` `
> ``

---
No further details from [SUREFIRE-1548](https://issues.apache.org/jira/browse/SUREFIRE-1548?redirect=false)

Start with the maven-failsafe-plugin configuration around forkCount and reuseForks, then trace how parallel test processes are started. The issue proposes a configurable delay such as DELAY_BETWEEN_TEST_STARTS; done should mean parallel execution still works while test starts are staggered by that interval.

Written by the indexing model from the issue text.