Web Start is working but jenkins says "Ping response time is too long or timed out" - windows

I can successfully start the connection from the slave with this command:
java -jar agent.jar -jnlpUrl https://myserver:8888/computer/myslave/slave-agent.jnlp -secret sdfsdfsdf -workDir "c:\jenkins"
It start, it runs, it logs 0 errors, I do netstat on the master and see the connection is established.
But it says its offline with the error "Ping response time is too long or timed out"
The error itself is troubling because the whole point of web start is so the master doesn't need direct access to the slave. Is it actually trying to icmp to the slave?
The slave can only access the master over port 8888.
I also see no logs anywhere for this, not on the slave or the master, how do I know what jenkins is even trying to do?

I was trying to allow this slave connection through a firewall.
I thought I could get away with one port for this.
My thinking was, opening up jenkins on port 8888 and listen to jnlp on port 8888 then connect with command java -jar agent.jar -jnlpUrl https://myserver:8888/computer/myslave/slave-agent.jnlp ....
But I needed open up port 433 so i could connect to the server over https first and connect like java -jar agent.jar -jnlpUrl https://myserver/computer/myslave/slave-agent.jnlp ..... Then also open port 8888 so the jenkins server could redirect to that jnlp port.
I was making a jnlp connection directly to that open port, the problem was I needed to connect to the jenkins server and let the server setup that jnlp connection

Related

Gatsby on EC2 doesn't connect externally

I have a development installation of Gatsby Doc site running on my EC2 server.
When I run the code on my dev machine it works and I can connect my browser to port 8000 and everything is ok..
On my server i check out my github code and
yarn install
npm run start.
Everything builds correctly and Gatsby it listening on port 8000
From my dev machine when I connect using
X.X.X.X:8000 in my browser i receive
Unable to connect
I have opened the port on 8000 in the firewall and I have tested that it works as expected using:
nc -lv 8000
on the server (where gatsby is going to run) and connect using telnet.
on the server i receive
Listening on [0.0.0.0] (family 0, port 8000)
Connection from 84.232.Y.Y 38552 received!
So it works.
When Gatsby is finished starting i see
You can now view gatsbyjs.org in the browser. ⠀ http://localhost:8000/
⠀
when i enter the web address and port i receive
Unable to connect
again. do I need to start Gatsby in another mode?
Kim
I found out.
I just added -H 0.0.0.0 to the start up command and everything works now.

Trying to setup Master Slave setup of Jmeter in Cloud, Receiving "java.net.ConnectException: Connection timed out: connect"

I'm Trying to setup Master Slave setup of Jmeter in Cloud.
Things I have done the setup in CLOUD for Master and Slave
I have created rmi.keystore.jks file in Master and copied the same to Slave machine.
I have installed the same versions of Java and Jmeter in both the Machines
I have added IP address of Slave machine in jmeter.properties file of Master
Please help me why I'm facing connection timed out error when trying to execute jmeter script in Cloud machine. Receiving:
Connection refused to host: 10.XXX.XX.XXX; nested exception is: java.net.ConnectException: Connection timed out: connect
If this is really in CLOUD then:
My expectation is that you need to use external IP addresses as I can only see Class B network-type address which most probably cannot be connected from the outer world
You need to ensure that the following ports are open in the CLOUD (whatever you mean by this term) and in operating system firewalls/security groups:
1099 (or whatever port you define as the server_port)
the port you define as the server.rmi.localport
the port(s) you define as the client.rmi.localport
More information:
Remote hosts and RMI configuration
How to Perform Distributed Testing in JMeter

Java mail client can't reach SMTP server from Docker container

I have created simple Java application which sends emails. It's working properly when I running it from my IDE, but when running it inside a Docker container it can't reach the remote SMTP server. I'm using
docker run -d -p 25:25 [image]:[tag]
to expose port 25 when starting the container. Does anyone has an idea why the mail client can't connect?
I think you are confusing the point of the port mapping. This is to allow the host to bind the specified port on the given network interface to the port in the container. In your case you are trying to connect to port 25 i presume on another remote host.
If the app works when run in the IDE I'd assume either an issue resolving the SMTP server or a problem with the address on which the SMTP server is listening.
Are you running the SMTP server locally or connecting to one that is resolvable via public DNS? If you use docker exec to enter the running container can you telnet to the SMTP server?

Postgresql refusing connection to server

I have been trying to connect to my postgresql 9.3 server but I keep getting this error.
Server doesn't listen
The server doesn't accept connections: the connection library reports
could not connect to server: Connection refused (0x0000274D/10061)
Is the server running on host "localhost" (::1) and accepting TCP/IP
connections on port 5433? could not connect to server: Connection
refused (0x0000274D/10061) Is the server running on host "localhost" (127.0.0.1)
and accepting TCP/IP connections on port 5432?
I have tried connecting through pgadmin3 and the command line.
psql.exe -h localhost -U postgres
This command also gives the same error.
I am on a windows machine. I have tried creating a separate server also with the same result.
I have no idea whats happening. Please help.
Thanks
As the error clearly tells or asks actually, Is the server running on host "localhost"?
So the chances are, the Postgres server is not running on your machine.
You can start the service(the layman way) by going to services and starting the service.
Here is how you do it:
Open Run Window by Winkey + R
Type services.msc
Search Postgres service based on the version installed.
Click stop, start or restart the service option.
Start the server with postgres -D ['data folder']
As in docs:
http://www.postgresql.org/docs/9.1/static/server-start.html
So in my Windows postgres installation from the bin folder:
postgres.exe -D ..\data
where data is in the postgresql installation folder
I had the same issue like Venkatesh had. But in my case I had installed pgadmin in version 9. But also installed version 12 at the same time.
When I now uninstalled version 9, the port was already set in the config of version 12 and not given free.
So my solution was to change the port of version 12 in the postgresql.conf file. Or even simplier, change the port in the server creation from 5432 to 5433. Now you are able to create a server again.
I got this same error. This happened when I uninstall and re-install postgress, for some reason after second-time installation, pgadmin tries to connect to the server on port 5433 whereas the server is running on 5432.
Rightclick server properties and change the port to 5432 and try to connect again. It should work now.
Your server running on port 5432 but in the properties, the port is set to 5433.
You must go to pgAdmin, click on database version, ex: PostgresSQL 10 and edit properties.
A new window appears and you need to change the port to 5432 [this is default port].
Hope this helps.

SSH -L connection successful, but localhost port forwarding not working "channel 3: open failed: connect failed: Connection refused"

My lab runs RStudio on a server. A couple weeks ago, from my cousin's house, I successfully ssh'd into the server and pulled up the server-side RStudio through my local Firefox browser. Now when I try to access the server RStudio from home (via my own router), it doesn't work. I need help troubleshooting, and I'm guessing it's some problem on the router. I'm running Mac OSX 10.6.8. No idea what the university server's running, but I don't think it's a server-side problem.
Here's how it worked the first time I did it, at my cousin's house: first, I VPN into the university network; then I call SSH with port forwarding; then I open a Firefox browser, connect to my localhost port, and it opens up RStudio on the server side which I can access through my local browser window.
Here's the problem I'm having right now when I try to log-in from my home network:
I can make the VPN connection successfully. I can also set up SSH successfully with this command:
ssh -v -L 8783:localhost:8783 myacct#server.com
Here are the last several lines of the verbose output from the successful ssh command:
debug1: Authentication succeeded (password).
debug1: Local connections to LOCALHOST:8783 forwarded to remote address localhost:8783
debug1: Local forwarding listening on 127.0.0.1 port 8783.
debug1: channel 0: new [port listener]
debug1: Local forwarding listening on ::1 port 8783.
debug1: channel 1: new [port listener]
debug1: channel 2: new [client-session]
debug1: Entering interactive session.
Last login: Mon Sep 2 04:02:40 2013 from vpnipaddress
So I think I'm still succeeding at the VPN and SSH stage (though I don't know why it says my last login was Sep 2 when I've logged in a few times since then).
Next, I open Firefox, and I type localhost:8783, and instead of getting an RStudio server app through my browser window, I get the following errors:
In the Firefox browser window, it says: Server not found, Firefox can't find the server at www.localhost.com, Check the address for typing errors etc.
In the terminal window, it says:
debug1: Connection to port 8783 forwarding to localhost port 8783 requested.
debug1: channel 3: new [direct-tcpip]
channel 3: open failed: connect failed: Connection refused
debug1: channel 3: free: direct-tcpip: listening port 8783 for localhost port 8783, connect from 127.0.0.1 port 50420, nchannels 4
I'm not sure what I've got wrong. I haven't changed anything on my laptop since my last successful connection. I'm on my own router (instead of my cousin's), so maybe I need to mess with the firewall? I already allowed ports 22 and 8783 to come through the firewall to my laptop (I'm not even sure I needed to do that though). Help?
ssh -v -L 8783:localhost:8783 myacct#server.com
...
channel 3: open failed: connect failed: Connection refused
When you connect to port 8783 on your local system, that connection is tunneled through your ssh link to the ssh server on server.com. From there, the ssh server makes TCP connection to localhost port 8783 and relays data between the tunneled connection and the connection to target of the tunnel.
The "connection refused" error is coming from the ssh server on server.com when it tries to make the TCP connection to the target of the tunnel. "Connection refused" means that a connection attempt was rejected. The simplest explanation for the rejection is that, on server.com, there's nothing listening for connections on localhost port 8783. In other words, the server software that you were trying to tunnel to isn't running, or else it is running but it's not listening on that port.
Posting this to help someone.
Symptom:
channel 2: open failed: connect failed: Connection refused
debug1: channel 2: free: direct-tcpip:
listening port 8890 for 169.254.76.1 port 8890,
connect from ::1 port 52337 to ::1 port 8890, nchannels 8
My scenario; i had to use the remote server as a bastion host to connect elsewhere. Final Destination/Target: 169.254.76.1, port 8890. Through intermediary server with public ip: ec2-54-162-180-7.compute-1.amazonaws.com
SSH local port forwarding command:
ssh -i ~/keys/dev.tst -vnNT -L :8890:169.254.76.1:8890
glue#ec2-54-162-180-7.compute-1.amazonaws.com
What the problem was:
There was no service bound on port 8890 in the target host. i had forgotten to start the service.
How did i trouble shoot:
SSH into bastion host and then do curl.
Hope this helps.
Note: localhost is the hostname for an address using the local (loopback) network interface, and 127.0.0.1 is its IP in the IPv4 network standard (it's ::1 in IPv6). 0.0.0.0 is the IPv4 standard "current network" IP address.
I experienced this error with a Docker setup. I had a Docker container running on an external server, and I'd (correctly) mapped its ports out as 127.0.0.1:9232:9232. By port-forwarding ssh remote -L 9232:127.0.0.1:9232, I'd expected to be able to communicate with the remote server's port 9232 as if it were my own local port.
It turned out that the Docker container was internally running its process on 127.0.0.1:9232 rather than 0.0.0.0:9232, and so even though I'd specified the container's port-mappings correctly, they weren't on the correct interface for being mapped out.
In my case, it worked after running the vncserver on linux.
Entered this on linux command line : sudo ssh -L 5901:localhost:5901 -i <ssh_private_key> <username>#<public-IP-address>
Type there vncserver
Go to VncViewer application and connect using localhost:5901
I used to meet the similar problem because 'localhost' was not available on server when it restarted network service, e.g. 'ifdown -a' but followed by only 'ifup -eo1'. Besides server is not listening to the port, you can also check 'localhost' is available or not.
ps: Post it just hope someone who has the similar problem may benefit.
I had this problem when I wanted to make a vnc connection via a tunnel.
But the vncserver was not running.
I solved it by opening the channel on the remote machine with vncserver :3.
In my case, it worked after checking the correct IP address of the user credentials
previously I was using the wrong IP of the server
ssh -NfL 127.0.0.1:8084:127.0.0.1:8888 user#ip_address_of_server
after correcting it, works fine.
Encountered with the same error.
In my case, I found the problem was in the config file of jupyter.
Let's say there are 3 computers named A, B, and C, and A can access B but can't access C; B can access C.
To access jupyter-notebook service of C from A, first I established ssh tunnel from A to C through B, then I access jupyter-notebook by typing localhost:port_number, then I got the error.
Finally the problem was solved by writing the "c.NotebookApp.ip = '0.0.0.0'" in jupyter-notebook's config file, where '0.0.0.0' allows the access of other IPs.
Hope someone in a similar situation may benefit.
I had the same error when I was trying to tunnel my mlflow ui over ssh to view remotely. As mentioned in the first answer, the error arises because nothing on the server is listening for the port. This, for me, is because I forgot to start the mlflow app on my remote machine! So in general – make sure the app you're trying to access remotely is running.
Just replace localhost with 127.0.0.1.
(The answer is based on answers of other people on this page.)
This means the remote vm is not listening to current port i solved this by adding the port in the vm server

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