When manual healing is triggered, one node in a cluster will
become the authority to heal. mc regularly sends new requests
to fetch the status of the ongoing healing process, but a load
balancer could land the healing request to a node that is not
doing the healing request.
This PR will redirect a request to the node based on the node
index found described as part of the client token. A similar
technique is also used to proxy ListObjectsV2 requests
by encoding this information in continuation-token
Golang proactively prints this error
`http: proxy error: context canceled`
when a request arrived to the current deployment and
redirected to another deployment in a federated setup.
Since this error can confuse users, this commit will
just hide it.
