Differences between revisions 2 and 11 (spanning 9 versions)

Corosync and HA-proxy

We will use corosync to create a virtual IP-address which is shared by two systems. One of the systems has the virtual IP-address. If the system goes down, the other system will take over the virtual IP-address. HA-proxy will be running on each of the hosts relaying incoming HTTP-requests to two webservers.

192.168.1.47 www (virtual IP-address)
192.168.1.48 haproxy01
192.168.1.49 haproxy02

Software

apt-get install corosync haproxy crmsh

Configuration

Before binding to the DNS name www make sure the DNS server knows that name.

HA-proxy

Add the following to /etc/haproxy/haproxy.cfg

listen webfarm 
        bind www:80
        mode http
        balance roundrobin
        cookie LBN insert indirect nocache
        option httpclose
        option forwardfor
        server haproxy01 www01:80 cookie node1 check
        server haproxy02 www02:80 cookie node2 check

Restart HA-proxy

service haproxy restart

Corosync

Add the local network and a multicast address to /etc/corosync/corosync.conf in the interface section

interface {
        bindnetaddr: 192.168.1.0 
        mcastaddr: 239.192.1.1
}

Restart corosync to load the new configuration.

service corosync restart

Commmands

Run the following on startup

   1 # do not kill other node
   2 crm configure property stonith-enabled=false
   3 # disable quorum due to two nodes only
   4 crm configure property no-quorum-policy=ignore
   5 # configure shared IP
   6 crm configure primitive haproxySharedIP  ocf:heartbeat:IPaddr2 params ip=192.168.1.47 cidr_netmask=24 op monitor interval=5s
   7 # create heartbeat for haproxy
   8 crm configure primitive haproxyLoadBalance ocf:heartbeat:haproxy params conffile=/etc/haproxy/haproxy.cfg op monitor interval=10s
   9 
  10 # make sure the same server has both IP and service
  11 #crm configure group haproxyIPs haproxySharedIP meta ordered=false
  12 crm configure group haproxy haproxySharedIP haproxyLoadBalance
  13 # relation between IP and haproxy servers
  14 crm configure colocation haproxyWithIPs INFINITY: haproxyLoadBalance haproxySharedIP
  15 # IP should be up before haproxy starts
  16 crm configure order haproxyAfterIPs mandatory: haproxySharedIP haproxyLoadBalance 
  17 #wget http://github.com/russki/cluster-agents/raw/master/haproxy
  18 #echo "net.ipv4.ip_nonlocal_bind = 1" >> /etc/sysctl.conf
  19

None: Corosync and HA-proxy (last edited 2021-08-12 09:31:08 by Kristian Kallenberg)

-  ⇤ ← Revision 2 as of 2018-01-08 20:21:20 → 
  Size: 355
  Editor: Kristian Kallenberg
  Comment:
+   ← Revision 11 as of 2018-01-10 00:12:54 → ⇥
  Size: 2455
  Editor: Kristian Kallenberg
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
-= Corosync =
+= Corosync and HA-proxy =
 Line 3:
+We will use corosync to create a virtual IP-address which is shared by two systems. One of the systems has the virtual IP-address. If the system goes down, the other system will take over the virtual IP-address. HA-proxy will be running on each of the hosts relaying incoming HTTP-requests to two webservers.
-Line 4:
+Line 5:
-None of what you see below is true!
+ * 192.168.1.47 www (virtual IP-address)
 * 192.168.1.48 haproxy01
 * 192.168.1.49 haproxy02
-Line 6:
+Line 9:
-We will use corosync to create a virtual IP which is share by two systems
+== Software ==
{{{
apt-get install corosync haproxy crmsh
}}}
-Line 8:
+Line 14:
-This has to be configured before haproxy configuration makes any sense, since haproxy should listen on the virtual ip. also we need to configure the dns name for the virtual ip first. so this depends on dns updates too.
+== Configuration ==
Before binding to the DNS name `www` make sure the DNS server knows that name.
 
=== HA-proxy ===
Add the following to `/etc/haproxy/haproxy.cfg`
{{{
listen webfarm 
        bind www:80
        mode http
        balance roundrobin
        cookie LBN insert indirect nocache
        option httpclose
        option forwardfor
        server haproxy01 www01:80 cookie node1 check
        server haproxy02 www02:80 cookie node2 check
}}}

Restart HA-proxy
{{{
service haproxy restart
}}}

=== Corosync ===
Add the local network and a multicast address to `/etc/corosync/corosync.conf` in the `interface` section
{{{
interface {
        bindnetaddr: 192.168.1.0 
        mcastaddr: 239.192.1.1
}
}}}

Restart corosync to load the new configuration.
{{{
service corosync restart
}}}

== Commmands ==
Run the following on startup
{{{#!highlight bash
# do not kill other node
crm configure property stonith-enabled=false
# disable quorum due to two nodes only
crm configure property no-quorum-policy=ignore
# configure shared IP
crm configure primitive haproxySharedIP  ocf:heartbeat:IPaddr2 params ip=192.168.1.47 cidr_netmask=24 op monitor interval=5s
# create heartbeat for haproxy
crm configure primitive haproxyLoadBalance ocf:heartbeat:haproxy params conffile=/etc/haproxy/haproxy.cfg op monitor interval=10s

# make sure the same server has both IP and service
#crm configure group haproxyIPs haproxySharedIP meta ordered=false
crm configure group haproxy haproxySharedIP haproxyLoadBalance
# relation between IP and haproxy servers
crm configure colocation haproxyWithIPs INFINITY: haproxyLoadBalance haproxySharedIP
# IP should be up before haproxy starts
crm configure order haproxyAfterIPs mandatory: haproxySharedIP haproxyLoadBalance 
#wget http://github.com/russki/cluster-agents/raw/master/haproxy
#echo "net.ipv4.ip_nonlocal_bind = 1" >> /etc/sysctl.conf

}}}