Forum: Installation

Post: Starting Database in VOLTDB Enterprise Manager 3.5

Starting Database in VOLTDB Enterprise Manager 3.5
mostafa
Aug 22, 2013
Hello ,

i tried to start the database on two nodes(two ubuntu servers) using the the voltdb enterprise manager but i got the following error

"SSH credential test failed for server " although there are already existing ssh connection between the two nodes.

Steps :-
1.i created public key using the command ssh-keygen -t rsa
2.send the key file to nodeB using the command ssh-copy-id root@nodeB
3.testing the ssh connection using the command ssh root@nodeB -i .ssh/id_rsa
4.successfully login to nodeB
5. running voltdb enterprise manager on nodeA
6.then opened the voltdb enterprise manager from external machine (with windows xp )using http://nodeA:9000/
7.then i created the database
8.i added two servers nodeA,nodeB(tried with and without the private key files).
9.start the database
10.got the error "SSH credential test failed for server " for the two servers

so can you please help to fix this issue?


Regards,
Mostafa
mostafa
Aug 25, 2013
Hello,

when i checked the logs ,i found the following error :-

com.jcraft.jsch.JSchException: Session.connect: java.net.SocketTimeoutException: Read timed out
at com.jcraft.jsch.Session.connect(Session.java:557)
at com.jcraft.jsch.Session.connect(Session.java:183)
at org.voltdb.processtools.SSHTools.cmdSSH(SSHTools.java:108)
at org.voltdb.processtools.SSHTools.cmdSSH(SSHTools.java:68)
at org.voltdb.processtools.SSHTools.cmd(SSHTools.java:59)
at org.voltdb.management.Server.cmd(Server.java:148)
at org.voltdb.management.CheckSSH.run(CheckSSH.java:29)
at org.voltdb.management.DiscoverAction.call(DiscoverAction.java:72)
at org.voltdb.management.DiscoverAction.call(DiscoverAction.java:35)
at org.voltdb.management.ActionBase.run(ActionBase.java:139)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at org.voltcore.utils.CoreUtils$1$1.run(CoreUtils.java:265)
at java.lang.Thread.run(Thread.java:662)

So i think the problem appeared when the ssh connection take a longer time to connect to another machine -even it is connected successfully at the end - and this prevents starting the database from the enterprise manager.

Regards,
Mostafa
mostafa
Aug 25, 2013
fixed by

add "UseDNS no" to /etc/ssh/sshd_config
add the client's net address to the server's /etc/hosts