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. There is no physical or virtual network interfaces, so the DNS updates has to be done manually.

Corosync

Encryption

Edit /etc/corosync/corosync.conf and make the following changes.

totem {
        crypto_cipher: aes256
        crypto_hash: sha512
}

Certificates

Generate the certificates. Note that this requires entropy, so use your system and the entropy will be generated. Speed this up by running dd if=/dev/vda of=/dev/null in another terminal.

corosync-keygen

Network

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

Nodes

Do not kill the 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-address.

crm configure primitive haproxySharedIP  ocf:heartbeat:IPaddr2 params ip=192.168.1.47 cidr_netmask=24 op monitor interval=5s

THIS HAS TO BE TESTED

# 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

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

References

https://wiki.debian.org/Debian-HA/ClustersFromScratch

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

-  ⇤ ← Revision 8 as of 2018-01-09 23:51:50 → 
  Size: 864
  Editor: Kristian Kallenberg
  Comment:
+   ← Revision 29 as of 2018-01-20 15:30:52 → ⇥
  Size: 3140
  Editor: Kristian Kallenberg
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
+Incomplete, do not use!
-Line 5:
+Line 7:
- * 192.168.1.47 virtual IP-address
+ * 192.168.1.47 www (virtual IP-address)
-Line 11:
+Line 13:
-apt-get install corosync haproxy
+apt-get install corosync haproxy crmsh
-Line 15:
+Line 17:
-Add the local network and a multicast address to `/etc/corosync/corosync.conf` in the `interface` section
+Before binding to the DNS name `www` make sure the DNS server knows that name. There is no physical or virtual network interfaces, so the [[DNS Updates|DNS updates]] has to be done manually.

=== Corosync ===

==== Encryption ====
Edit `/etc/corosync/corosync.conf` and make the following changes.
{{{
totem {
        crypto_cipher: aes256
        crypto_hash: sha512
}
}}}

==== Certificates ====
Generate the certificates. Note that this requires entropy, so use your system and the entropy will be generated. Speed this up by running `dd if=/dev/vda of=/dev/null` in another terminal.
{{{
corosync-keygen
}}}

==== Network ====
Add the local network and a multicast address to `/etc/corosync/corosync.conf` in the `interface` section.
-Line 28:
+Line 50:
-== Commmands ==
Run the following on startup
+==== Nodes ====
Do not kill the other node.
-Line 31:
+Line 53:
+crm configure property stonith-enabled=false
}}}
Disable quorum due to two nodes only.
{{{
crm configure property no-quorum-policy=ignore
}}}
Configure shared IP-address.
{{{
crm configure primitive haproxySharedIP  ocf:heartbeat:IPaddr2 params ip=192.168.1.47 cidr_netmask=24 op monitor interval=5s
}}}

THIS HAS TO BE TESTED
{{{
# 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
-Line 33:
+Line 80:
+=== 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
}}}




== References ==
  * https://wiki.debian.org/Debian-HA/ClustersFromScratch