This question is more of an NFSv4.1 protocol question thus I would encourage you to ask it on the nfsv4@xxxxxxxx. On Tue, Mar 19, 2019 at 11:06 PM Marvin Zhang <fanzier@xxxxxxxxx> wrote: > > Hi Experts, > Here are some questions about trunking: > 1. For session trunking. During first mount(or first connection), > client create a session. During the second mount(or second > connection), client will reuse the session which the first connection > created. Does the second mount create a new super block or reuse the > previous? > If there is a READ request on this session, how to judge to > use which connection? Session trunking does not require the client to create a different mount in your example. A single mount could have multiple TCP connections established between a client and a server and they would use the same NFSv4.1 session to send operations to the server. A read operation issued by the application using the NFS mount could use one of those connection and the question which one it would use is protocol implementation specific. Simplest implementation round robins connections for incoming RPC tasks. If the client mounted a server and then decides to mount the same server again (given same mount options and credentials), in the linux implementation, the existing NFS client (and its TCP connection) would be re-used. Thus it would not be a case of session trunking. > 2. For client id truking. As protocol said, client can create multipl > session at the same time. I can't understand in which scenario client > can create multiple session Again IETF list can provide some examples and motivations for the clientid case. I think perhaps it was for the clustered server environment where the client would use the same client id across different cluster nodes but it would establish unique sessions to the nodes.
