Bug 52073 and commit of JMeterPoolingClientConnectionManager

[Philippe Mouawad <ph...@gmail.com>]

Hello,
Within bug:
- https://bz.apache.org/bugzilla/show_bug.cgi?id=52073

I commited a temporary class with package "org.apache.http.impl.conn" as I
need to access:

   - HttpConnPool (package protected)

This class is inspired from the new PoolingHttpClientConnectionManager and
is here only to introduce the new validation mechanism.

It is intended to  disappear after full upgrade to HttpClient 4.5.X and
particularly to PoolingHttpClientConnectionManager.


Why this is needed ?

In HttpClient 4.4, Oleg introduced for us (JMeter) a new validation
mechanism which is much more efficient than the previously existing one
(http.connection.stalecheck$Boolean=true).

This validation mechanism is based on :

   - time to live of connection (httpclient4.time_to_live=2000)
   - validation of connections not for each call but after some inactivity
   time (httpclient4.validate_after_inactivity=2000)

Within the benchmarks I made on Bug 52073, I noticed that I faced some
NoHttpResponse (0.02%) due to invalid connection usage which increases when
throughput increases.

After introducing this new mechanism , these errors disappeard.
Regards
Philippe