[Tarantool-patches] [PATCH vshard 3/7] test: disable router discovery for some tests

[Oleg Babin]

Hi. Thanks for the patch. LGTM. But I have a question.

On 01/05/2020 03:16, Vladislav Shpilevoy wrote:
> There are tests, which are not related to discovery at all, and
> yet they suffer from unrelated changes, when something is modified
> in the discovery algorithm. For example, it highly affects the
> test about request retries and automatic timeouts.
> 
> Now the discovery is disabled for such tests, since it becomes
> easily possible to do with the new router's configuration option.
> ---
> -_ = test_run:cmd("start server router_1")
> +-- Discovery algorithm changes sometimes and should not affect the
> +-- exponential timeout test.
> +_ = test_run:cmd("start server router_1 with args='discovery_disable'")
>   ---
>   ...
>   _ = test_run:switch('router_1')
> @@ -49,13 +51,13 @@ util.collect_timeouts(rs1)
>       ok: 0
>       timeout: 0.5
>     - fail: 0
> -    ok: 1
> +    ok: 0
>       timeout: 0.5
>   ...
>   util.collect_timeouts(rs2)
>   ---
>   - - fail: 0
> -    ok: 1
> +    ok: 0
>       timeout: 0.5
>     - fail: 0
>       ok: 0
> @@ -74,7 +76,7 @@ util.collect_timeouts(rs1)
>       ok: 0
>       timeout: 0.5
>     - fail: 0
> -    ok: 9
> +    ok: 8
>       timeout: 0.5
>   ...
>   _ = rs1:callrw('echo')
> @@ -86,7 +88,7 @@ util.collect_timeouts(rs1)
>       ok: 0
>       timeout: 0.5
>     - fail: 0
> -    ok: 1
> +    ok: 9
>       timeout: 0.5
>   ...

Sorry for maybe quite stupid question, but why does it quite 
significantly increase?
```
net_sequential_ok - count of sequential success requests to the replica
```