Detail
When following the standard quiescing operating procedure, the client still get exceptions when the node is shut down, defeating the purpose of quiescence.
Answer
One potential cause for such situation is when the client is not able to properly refresh its partition map. This would cause the existing partition map to be used and the quiesced node to be accessed, causing proxies and causing errors when the quiesced node is shut down. It is therefore important to check the network and/or potential issues with older client libraries.
Check the proxy_in_progress and client_proxy_complete statistics for evidence of proxies going on prior to shutting down a quiesced node.
There is another situation where a quiesced node would be hit: if the cluster is using rack-aware and the client is using the PREFER_RACK ReplicaPolicy. In such cases, against older server versions, the client will continue hitting the quiesced node which would then proxy to the right node, causing errors and connection exception when it is shutdown.
Version 4.6.0.2 addresses this issue.