Accessing my Jenkins 2.319.1 instance via SSH get very slow a few days ago. I don't know what changed.
To narrow it down: Accessing Jenkins via HTTPS API is OK. The performance of the Web API is OK, too.
$ java -jar jenkins-cli.jar -s https://my-jenkins-server help # ~3s => OK
However, with the SSH API:
$ java -jar jenkins-cli.jar -s https://my-jenkins-server -ssh -i ~/.ssh/id_rsa -user my-user-name help
Jan 23, 2023 6:18:48 PM io.jenkins.cli.shaded.org.apache.sshd.common.util.security.AbstractSecurityProviderRegistrar getOrCreateProvider
INFO: getOrCreateProvider(EdDSA) created instance of io.jenkins.cli.shaded.net.i2p.crypto.eddsa.EdDSASecurityProvider
Jan 23, 2023 6:18:49 PM io.jenkins.cli.shaded.org.apache.sshd.common.io.DefaultIoServiceFactoryFactory getIoServiceProvider
INFO: No detected/configured IoServiceFactoryFactory using Nio2ServiceFactoryFactory
Jan 23, 2023 6:18:49 PM io.jenkins.cli.shaded.org.apache.sshd.client.config.hosts.ConfigFileHostEntryResolver reloadHostConfigEntries
INFO: resolveEffectiveResolver([email protected]:50022) loaded 1 entries from /home/my-user-name/.ssh/config
io.jenkins.cli.shaded.org.apache.sshd.common.SshException: DefaultAuthFuture[ssh-connection]: Failed to get operation result within specified timeout: 10000
at io.jenkins.cli.shaded.org.apache.sshd.common.future.AbstractSshFuture.formatExceptionMessage(Abstrac[..]
To work around the timeout of jenkins-cli.jar and to get more output, I use raw ssh:
ssh -v -a -x my-jenkins-server -l my-username -p 50022 help # 10 to 60 seconds
10 to 60 seconds for a simple help call! Same for who-am-i!
The debug output tells me that the SSH API of Jenkins stalls after some requests of the SSH client.
Here is the interesting part of ssh ... |& ts -i:
00:00:00 debug1: Next authentication method: publickey
00:00:00 debug1: Offering RSA public key: /home/my-username/.ssh/id_rsa
00:00:05 debug1: Server accepts key: pkalg ssh-rsa blen 407
00:00:04 debug1: Authentication succeeded (publickey).
00:00:00 Authenticated to my-jenkins-server.
00:00:00 debug1: channel 0: new [client-session]
00:00:00 debug1: Entering interactive session.
00:00:00 debug1: pledge: network
00:00:00 debug1: Sending environment.
00:00:00 debug1: Sending env LC_PAPER = de_DE
00:00:00 debug1: Sending env LANG = C
00:00:00 debug1: Sending env LC_CTYPE = en_US.UTF-8
00:00:00 debug1: Sending command: help
00:00:04 add-job-to-view
00:00:00 Adds jobs to view.
[more help output]
Any idea about the performance issue of the SSH API?
