Add pool max fails logic

[KaymeKaydex]

it is necessary to give and write the logic of behavior in case of unavailability of one of the nodes, I suggest using a similar approach with nginx and the max_fails setting in upstream

https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#upstream

[oleg-jukovec]

I think we can not give such a guarantee due to an asynchronous nature of the connector: you could push N requests to a connection and only than get an error.