跨多台机器进行Wildfly负载平衡

Question

I am trying to configure a wildfly server with a load balancer for learning purposes. Here's what I got:

• Three VMs, only accessible by their IPs.
  • One is 152.238.224.58 - my load balancer
  • An other one is 152.238.224.59 - my first backend server
  • The last one is 152.238.224.60 - my second backend server

I find the wildfly documentation to be rather poor, but after watching Stuart Douglas's explanation on how the load balancer works, I currently have my first VM running a cluster of servers. Load balancing works, but everything is on the same VM (the first one). What I'd rather have is the load balancer acting as a proxy for the two backend servers.

I've tried the method described on the Wildfly documentation but didn't manage to make it work.

What would I need to do to have the first VM load-balancing across the two second VMs? To go even further, how difficult would it be to have the first VM act as a load-balancer between VM-2 and VM-3, where VM-2 and VM-3 are clusters (would they then have their own load-balancer?)?

Thanks a lot for any indication.

Answer 1

From WildFly version 10.1 there is a load balancer profile as a part of WildFly installation. Just use it. I'm providing sample steps here (based on my demo scripts for MS Azure ).

Load balancer

Use the standalone-load-balancer.xml profile for the load balancer. WildFly 10.1 has the profile within the examples. WildFly 11 has it as a standard profile in the configuration directory.

WILDFLY_HOME=/path/to/wildfly
# MY_IP=$(ip route get 8.8.8.8 | awk '{print $NF; exit}')
MY_IP=152.238.224.58

# Skip following command in WildFly 11
cp $WILDFLY_HOME/docs/examples/configs/standalone-load-balancer.xml \
    $WILDFLY_HOME/standalone/configuration/

# run the load balancer profile
$WILDFLY_HOME/bin/standalone.sh -b $MY_IP -bprivate $MY_IP -c standalone-load-balancer.xml

This script uses for communication between worker nodes and load balancer public network. If you want to use a private network (highly recommended), then set the correct IP address of the balancer for private interface ( -bprivate ).

Worker nodes

Run the server with the HA (or Full HA) profile, which has modcluster component included. If the UDP multicast is working in your environment, the workers should work out of the box without any change. If it's not the case, then configure the IP address of the load-balancer statically.

WILDFLY_HOME=/path/to/wildfly
MY_IP=$(ip route get 8.8.8.8 | awk '{print $NF; exit}')

# Configure static load balancer IP address.
# This is necessary when UDP multicast doesn't work in your environment.
LOAD_BALANCER_IP=152.238.224.58
$WILDFLY_HOME/bin/jboss-cli.sh <<EOT
embed-server -c=standalone-ha.xml
/subsystem=modcluster/mod-cluster-config=configuration:write-attribute(name=advertise,value=false)
/socket-binding-group=standard-sockets/remote-destination-outbound-socket-binding=proxy1:add(host=$LOAD_BALANCER_IP,port=8090)
/subsystem=modcluster/mod-cluster-config=configuration:list-add(name=proxies,value=proxy1)
EOT

# start the woker node with HA profile
$WILDFLY_HOME/bin/standalone.sh -c standalone-ha.xml -b $MY_IP -bprivate $MY_IP

Again, to make it safe, you should configure MY_IP as an address from the private network.