[dnsdist] server policy to failover to another pool

[Justin Valentini]

Hi Remi,


On 10/06/2017 08:17 AM, Remi Gacogne wrote:
> Hi Justin,
>
> On 10/06/2017 02:06 PM, Justin Valentini wrote:
>> I tried the orderedLeastOutstanding policy but ran into issues when
>> testing. If I explicitly set my order #1 server to down (e.g.
>> getServer(0):setDown()) dnsdist doesn't not directly traffic to the next
>> ordered server. Instead the query times out. However, when we bring down
>> the actual dns server and let dnsdist healthcheck it to down, it seems
>> to work.
>>
>> Do any of you know why this may be the case? Do isUp() and upStatus not
>> respect explicitly set DOWN state?
> The way it is currently handled might not be very intuitive. When you
> call setDown() or SetUp(), this sets the backend's "availability" state
> to Up or Down, instead of the default of Auto, but does not change the
> "upStatus".
> The isUp() method checks whether "availability" is set to Down or Up
> before checking "upStatus, so orderedLeastOutstanding should either use
> the isUp() method, or check the "availability" state before looking at
> "upStatus".

Using isUp() did the trick. Thank you!

-Justin