服务器节点未在jenkins CI中连接

Question

I have been trying to setup jenkins on my system and as i have a separate linux server for builds, i am connecting this server to jenkins as a slave agent, but even though ive given proper credentials, im facing this error when jenkins tried to launch the slave agent

Evacuated stdout

Slave successfully connected and online
[07/03/15 10:44:08] [SSH] Opening SSH connection to 10.169.41.66:22.
[07/03/15 10:44:08] [SSH] Authentication successful.

[07/03/15 10:44:09] [SSH] The remote users environment is:
BASH=/bin/bash
BASHOPTS=cmdhist:extquote:force_fignore:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
BASH_ALIASES=()
BASH_ARGC=()
BASH_ARGV=()
BASH_CMDS=()
BASH_EXECUTION_STRING=set
BASH_LINENO=()
BASH_SOURCE=()
BASH_VERSINFO=([0]="4" [1]="2" [2]="25" [3]="1" [4]="release" [5]="i686-pc-linux-gnu")
BASH_VERSION='4.2.25(1)-release'
DIRSTACK=()
EUID=1011
GROUPS=()
HOME=/home/pvi2cob
HOSTNAME=cob1046771
HOSTTYPE=i686
IFS=$' \t\n'
LANG=en_IN
LANGUAGE=en_IN:en
LOGNAME=pvi2cob
MACHTYPE=i686-pc-linux-gnu
MAIL=/var/mail/pvi2cob
OPTERR=1
OPTIND=1
OSTYPE=linux-gnu
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
PIPESTATUS=([0]="0")
PPID=6388
PS4='+ '
PWD=/home/pvi2cob
SHELL=/bin/bash
SHELLOPTS=braceexpand:hashall:interactive-comments
SHLVL=1
SSH_CLIENT='10.169.95.56 49934 22'
SSH_CONNECTION='10.169.95.56 49934 10.169.41.66 22'
TERM=dumb
UID=1011
USER=pvi2cob
XDG_SESSION_COOKIE=7be7fb574f0629ada47264330000027e-1435900448.726504-433426855
_=']'
[07/03/15 10:44:09] [SSH] Checking java version of java
[07/03/15 10:44:09] [SSH] java -version returned 1.6.0_31.
[07/03/15 10:44:09] [SSH] Starting sftp client.
[07/03/15 10:44:09] [SSH] Copying latest slave.jar...
[07/03/15 10:44:09] [SSH] Copied 346,845 bytes.
Expanded the channel window size to 4MB
[07/03/15 10:44:09] [SSH] Starting slave process: cd "/home/pvi2cob/jenkins" && java  -jar slave.jar
<===[JENKINS REMOTING CAPACITY]===>ERROR: Unexpected error in launching a slave. This is probably a bug in Jenkins.
java.lang.IllegalStateException: Already connected
    at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:427)
    at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:345)
    at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:812)
    at hudson.plugins.sshslaves.SSHLauncher.launch(SSHLauncher.java:598)
    at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:228)
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
[07/03/15 10:44:09] [SSH] Connection closed.

Answer 1

有类似这样的不知道你的詹金斯版本开放的问题，虽然- https://issues.jenkins-ci.org/browse/JENKINS-14332

Answer 2

This error occurs when the SSH Connection Pool on the Jenkins node is too small. Try setting the connection limit from 10 (default) to 1000.

Edit the /etc/ssh/sshd_config and insert MaxSessions 1000