Clarify in the docs that load balancing policies do not influence to which nodes connections are being opened

[piodul]

In some of the other drivers (Java, CPP) load balancing policies are able to influence to which nodes connections are being opened. For example, a LBP may be configured to only consider nodes from the local datacenter, so the session won't open connections to nodes from other DCs.

The scylla-rust-driver's architecture does not (currently?) allow for something like this. Instead, we have introduced the HostFilter abstraction which can allow users to explicitly choose to which nodes connections are being opened, independently of the LBPs used. However, this is not explicitly stated anywhere - users coming from other drivers may be confused and think that e.g. DcAwareRoundRobinPolicy::set_include_remote_nodes will have an effect on the set of nodes with open connections.

We should adjust the docs to clearly state this difference:

• In the main documentation page for load balancing policies,
• in the docstrings of methods that prevent the load balancing policy from considering all nodes in the cluster (e.g. aforementioned set_include_remote_nodes).

[havaker]

In the main documentation page for load balancing policies

It was clarified in #612

scylla-rust-driver/docs/source/load-balancing/load-balancing.md

Lines 10 to 13 in c5dd118

	Load balancing policies do not influence to which nodes connections are
	being opened. For a node connection blacklist configuration refer to
	`scylla::transport::host_filter::HostFilter`, which can be set session-wide
	using `SessionBuilder::host_filter` method.

in the docstrings of methods that prevent the load balancing policy from considering all nodes in the cluster (e.g. aforementioned set_include_remote_nodes).

Those methods were removed in #612 too.

I guess this can be closed now.

[piodul]

I guess this can be closed now.

Right, thanks.