Every client restart, pool creates new client instance. If client
failed due to dial error, there was no prior connection and go
routine on a server side. If client failed due to communication
or business logic errors, then server side maintains connection and
client should close it to avoid routine and connection leak.
Dialing is a part of healthcheck, so health status is now a enum
of three values:
- unhealthy due to dial fail,
- unhealthy due to transmission fail,
- healthy.
Signed-off-by: Alex Vanin <a.vanin@yadro.com>
