Connection to newly added node is initially unavailable with validateClusterNodeMembership: false.

[oklahomer]

This issue was previously discovered in another question-marked issue #339 .
Below shows detailed context and error content.

lettuce version

4.2.1

Contextual information

To maximize the availability, I applied some changes to client options: ClusterClientOptions and ClusterTopologyRefreshOptions.
Current settings are shown below:

ClientResources clientResources = DefaultClientResources.builder().build();
List<RedisURI> redisURIs = ...;
RedisClusterClient redisClusterClient = RedisClusterClient.create(clientResources, redisURIs);

ClusterTopologyRefreshOptions topologyRefreshOptions =
        ClusterTopologyRefreshOptions.builder()
                                     .enablePeriodicRefresh(INTERVAL_IN_SECONDS, TimeUnit.SECONDS)
                                     .enableAllAdaptiveRefreshTriggers()
                                     .build();

ClusterClientOptions clusterClientOptions =
        ClusterClientOptions.builder()
                            .validateClusterNodeMembership(false) // To acknowledge brand new nodes
                            .topologyRefreshOptions(topologyRefreshOptions)
                            .build();

redisClusterClient.setOptions(clusterClientOptions);

In this modification, ClusterClientOptions#validateClusterNodeMembership is set to false to acknowledge brand new nodes with new host:port regarding #109.
However, ClusterClientOptions#closeStaleConnections is left with default value: true. (Just got to have a hunch that this is somehow related...)

Simplest possible steps to reproduce

Create lettuce instance with above settings, add nodes to redis cluster, reshard, and an exception is thrown. It is thrown only once and later operations seem to run normally and as expected.

Thanks in advance.

[mp911de]

The reason for the failure: The newly created connection is opened in the same thread (EventLoop) that is assigned to the connection itself. Opening a new connection will assign a different EventLoop which is a different thread and so it eventually works. The solution should be retrying using the computation thread pool.

[mp911de]

That's fixed now.