SSH client creates 5 threads while connecting to host.

[uttamgupta]

Is there a way to configure NIO threads when we connect to a host? I have a use case where I need to connect to 64 hosts from a single client. However, this process takes an excessive amount of CPU time.
sshd-SshClient[2200ad1]-timer-thread-1
sshd-SshClient[2200ad1]-nio2-resume-thread-1
sshd-SshClient[2200ad1]-nio2-thread-1
sshd-SshClient[2200ad1]-nio2-thread-2
sshd-SshClient[2200ad1]-nio2-thread-3

[tomaswolf]

There is CoreModuleProperties.NIO_WORKERS, and if that is not sufficient, you could instantiate an IoServiceFactory with your own executor factory.

But are you sure the problem is the number of IO threads? Connecting to a host involves a key exchange, which involves cryptographic operations, and authentication, which may involve cryptographic operations (for instance for public-key authentication). Perhaps the bottleneck is in these cryptographic operations.

Maybe you can get some speed-up by having multiple application threads handling the SSH sessions, so that key exchange and authentication for different sessions can run concurrently.