I am trying to create a standalone cluster in Wildfly 8. I am referring to http://middlewaremagic.com/jboss/?p=1952. I was successful in creating the cluster on same machine, but can't create the same on different machines. I started the server on both machines as follows:
1) On machine 1 > Go to cmd > jboss-wildfly\bin > run following command:
standalone.bat -c standalone-ha.xml -b 10.10.54.27 -u 230.0.0.4 -Djboss.server.base.dir=../standalone -Djboss.node.name=nodeOne(10.10.54.27 is IP of machine 1)
1) On machine 2 > Go to cmd > jboss-wildfly\bin > run following command:
standalone.bat -c standalone-ha.xml -b 10.10.52.42 -u 230.0.0.4 -Djboss.server.base.dir=../standalone -Djboss.node.name=nodeTwo(10.10.52.42 is IP of machine 2)
The servers are getting started without any problem, but the nodes can't see each other. I used ClusterWebApp.war (downloaded from same site given above) for testing the cluster.
Am I missing something? Please help.
Most likely UDP broadcasting/multicasting is not allowed on your network (as of today, this would be the case on AWS VPCs for instance)
There is a test you can run to confirm this:
http://www.techstacks.com/howto/troubleshoot-jgroups-and-multicast-ip-issues.html
If this is the case, you may have to cluster using tcp. These links explain how this can be done
http://middlewaremagic.com/jboss/?p=2015
http://www.redhat.com/summit/2011/presentations/jbossworld/whats_new/wednesday/ban_w_310_running_in_the_cloud.pdf
I got the problem. For this kinda clustering to work, multicast protocol needed to be supported on network switches and routers. Previously I tried doing it on my laptop for which multicast protocol is enabled. So, I successfully created cluster on same machine (i.e. my laptop). However, other machine is one of the servers in my network, for which multicast was not enabled. Hence it was failing when tried on two different machines.Very basic problem!! After correcting this, cluster is working fine.
Related
I know k3d can do this magically via k3d cluster create myname --token MYTOKEN --agents 1, but I am trying to figure out how to do the most simple version of that 'manually'. I want to create a server something like:
docker run -e K3S_TOKEN=MYTOKEN rancher/k3s:latest server
And connect an agent something like like:
docker run -e K3S_TOKEN=MYTOKEN -e K3S_URL=https://localhost:6443 rancher/k3s:latest agent
Does anyone know what ports need to be forwarded here? How can I set this up? Nearly everything I try, the agent complains about port 6444 already in use, even if I disable as much as possible about the server with any combination of --no-deploy servicelb --disable-agent --no-deploy traefik
Feel free to disable literally everything other than the server and the agent, I'm trying to make this ultra ultra simple, but just butting my head against a wall at the moment. Thanks!
The containers must "see" each other. Docker isolates the networks by default, so "localhost" in your agent container is the agent container itself.
Possible solutions:
Run both containers without network isolation using --net=host, map API port of the server to the host with --port and use the host IP in the agent container or use docker-compose.
A working example for docker-compose is described here: https://www.trion.de/news/2019/08/28/kubernetes-in-docker-mit-k3s.html
I am attempting to set up a VM using VirtualBox. I am hosting on Windows 10 and want to set up a CentOS vm. I have a VM running but have had problems getting network connectivity with it. I have no experience with VirtualBox and it has been a long time since I worked on Linux. Any ideas on what I need to do to correct this? Are there some steps I need to take during the creation of the image?
Image is : CentOS-7-x86_64-Everything-1708.iso
VirtualBox : Version 5.1.28 r117968 (Qt5.6.2)
When I try to ping anything I get " connection the Network is unreachable
The very best thing you should do is running the following command:
ifconfig -a
Then, If you have an interface listed (not just 'lo'), you can do that:
# cd /etc/sysconfig/network-scripts/
# sed -i -e 's#^ONBOOT="no#ONBOOT="yes#' ifcfg-{{network_device}}
replace {{network_device}} for your default network_device (from ifconfig-a command).
Then restart and it should connect.
My Go application makes TLS connections via tls.Dial() to exchange data.
It works fine when run from the host:
But the outgoing connection doesn't seem to work when the app is run from a Docker container. The app hangs indefinitely.
Note 1: Same behavior with using docker run -p $(docker-machine ip):2500:2500 ...
Note 2: VM doesn't have extra port forwarding settings other than the default settings that came with docker-machine's default VM.
Docker image build with Dockerfile:
FROM golang:latest
RUN mkdir -p "$GOPATH/src/path/to/app"
# Install dependencies
RUN go get github.com/path/to/dep
VOLUME "$GOPATH/src/path/to/app"
EXPOSE 2500
WORKDIR "$GOPATH/src/path/to/app"
CMD ["go", "run", "main.go"]
Host is OS X running docker-machine.
Question
How can I make the TCP outgoing connection to work?
You are either using boot2docker or docker-machine (since you are running docker on OSX). If you are using boot2docker, you have to forward the ports on VirtualBox as well as docker, have a look at this blog post:
https://fogstack.wordpress.com/2014/02/09/docker-on-osx-port-forwarding/
If you are using docker-machine, you have to connect to the docker-machine assigned ip, not localhost, have a look at this post:
https://github.com/docker/machine/issues/710
I see now that you are using docker-machine specifically, so the post about docker-machine should answer your question.
Edit: I misunderstood the question. You are trying to make an outgoing connection on a forwarded port. That is not correct. By default docker can make outgoing connections on any port. The port forwarding is for incoming connections only. Please try again without specifying any ports to forward. My suspicion is that you are trying to make an outgoing connection on the incoming (forwarded) port.
I've just had exactly the same problem. Was unable to connect out at all.
Restarted the container, and suddenly outgoing connections worked fine. It's possible that the container survived an update of docker?
Currently using Docker version 18.09.3, build 774a1f4
I am running Centos 7 x86-64. I installed a guest (again Centos 7) through kickstart as an exercise. I prepared my kickstart file, I validated it and I launched with virt-install.
If something went wrong with the network configuration (During install I got no problem, I created a local repo on Host FTP server as source for the install) how can I connect to the machine?
Only SSH or virsh foresee some other connection method?
How can I find my machine running network configuration from outside?
I am running a barebone Centos7 installation so only command line, no graphical interface at all.
Thanks,
M.
You can ssh to your physical host from another one having graphical interface with X forwarding enabled (ssh -X machinename), and look at the the VM with virt-manager
You will need X running on the machine you're connecting from. For Mac OS it's XQuartz
I'm trying to run a distribution test for learning purpose and i'm using a Virtual machine Centos 7 as a slave in my Windows 7 ( master running in window 7) but even if i configure the master with the IP of the slave ( VM ), modifying the file jmeter.properties, doesn't work, i try run Jmeter-server in the Centos machine but this problem appears.
Created remote object: UnicastServerRef [liveRef: [endpoint:[127.0.0.1:44341](lo
cal),objID:[4e68a212:14a8564a618:-7fff, 5760053273490727502]]]
Server failed to start: java.rmi.RemoteException: Cannot start. localhost.locald
omain is a loopback address.
An error occurred: Cannot start. localhost.localdomain is a loopback address.
Can somebody give me a direction where look or a explanation how can i do it?
Thanks!
Put the following line in system.properties file: java.rmi.server.hostname=xxx.xxx.xxx.xxx
Alternatively start JMeter providing above property as a command-line argument as:
jmeter (or jmeter-server) -Djava.rmi.server.hostname=xxx.xxx.xxx.xxx
Double check your network configuration, i.e. make sure that your /etc/hosts file contains the following lines:
127.0.0.1 localhost localhost.localdomain
xxx.xxx.xxx.xxx your CentOS machine hostname
In all above cases xxx.xxx.xxx.xxx should be IP address of your CentOS machine and this IP address must be different from 127.0.0.1.
Also make sure that you select "Bridged" networking in your Virtual Machine, machines should be able to reach each other over the network, firewalls should be properly configured to allow communication, etc.
For more information on different JMeter Properties and ways of setting/overriding them see Apache JMeter Properties Customization Guide