Name
mbus.conf — Momentum Cluster Messaging Bus configuration file
Description
/opt/msys/ecelerity/etc/conf/global/mbus.conf configures the behavior of the Momentum Cluster Messaging Bus, mbusd. Configuration changes to the message bus cannot be made through the web UI, you must manually change mbus.conf. For instructions on doing this see “Best Practices for Manually Changing Configuration Files”.
Momentum's clustering solution makes heavy use of a group communication messaging bus called "Spread". Spread provides a mechanism for distributing data to various nodes in a networked configuration. Without this messaging bus, the nodes and the cluster manager cannot communicate and all cluster tasks such as DuraVIP™ binding, logging, and replication will cease to operate.
The cluster manager node and each Momentum node will pull the configuration from ecconfigd on a periodic basis (once per minute) and if the configuration has changed, the messaging bus will shut itself down and restart operations under the new configuration.
An initial configuration for the messaging bus is constructed as part of the installation process. Typically, this file is /opt/msys/ecelerity/etc/conf/global/mbus.conf.
Note
As of version 3.4, cluster communication is handled by the msgc modules rather than by mbus. Configuration is handled by the msgc_server.conf file. For more information see “msgc – Modules”.
SocketPortReuse = on DaemonUser = ecspread DaemonGroup = ecspread DebugFlags = { EXIT CONFIGURATION } RuntimeDir = /var/run/spread EventLogFile = /var/log/spread/mainlog EventTimeStamp DangerousMonitor = false # Subcluster: default => manager-0-1 Spread_Segment 10.0.0.255:4803 { # 10.0.0.255 is the bcast manager-0-1 10.0.0.91 # management node ec-0-1 10.0.0.191 # ecelerity node 1 ec-0-2 10.0.0.192 # ecelerity node 2 ec-0-3 10.0.0.193 # ecelerity node 3 ec-0-4 10.0.0.194 # ecelerity node 4 ec-0-5 10.0.0.195 # ecelerity node 5 ec-0-6 10.0.0.196 # ecelerity node 6 }
The above configuration listing illustrates a standard configuration. In this configuration, 10.0.0.255 is the network broadcast address. Inside the Spread_Segment declaration we see each participating node. The node name should match the output of the hostname command on that node. The IP interface on which the node's participating address resides must have the same broadcast address as this Spread_Segment, as reported by ifconfig.
If you need to edit the mbus.conf file, edit it in place and commit it to the repository using eccfg.
Note
The mbus.conf file is promulgated to cluster nodes by ecconfigd. It is advisable to restart ecconfigd after making extensive changes to mbus.conf, after adding multiple nodes for instance. Do this by issuing the command /etc/init.d/ecconfigd restart . It is also advisable to restart the ecelerity and the eccmgr processes.
Depending upon your configuration, there may be additional Spread_Segment stanzas. Spread_Segments are created both if the nodes are not all in the same net block as well as if there are multiple subclusters. A single subcluster with two segments might look like the following:
SocketPortReuse = on
DaemonUser = ecspread
DaemonGroup = ecspread
DebugFlags = { EXIT CONFIGURATION }
RuntimeDir = /var/run/spread
EventLogFile = /var/log/spread/mainlog
EventTimeStamp
DangerousMonitor = false
# Subcluster: default => rh52mgr.vmnet24.example.com
Spread_Segment 10.79.240.255:4803 {
rh52bar2 10.79.240.129
}
Spread_Segment 10.79.24.255:4803 {
rh52bare 10.79.24.130
rh52mgr 10.79.24.136
}
With multiple subclusters the Spread_Segments could be configured in the following way:
SocketPortReuse = on
DaemonUser = ecspread
DaemonGroup = ecspread
DebugFlags = { EXIT CONFIGURATION }
RuntimeDir = /var/run/spread
EventLogFile = /var/log/spread/mainlog
EventTimeStamp
DangerousMonitor = false
# Subcluster: east => rh52mgr.vmnet24.example.com
Spread_Segment 10.79.24.255:4803 {
rh52bare 10.79.24.130
rh52mgr 10.79.24.136
}
SocketPortReuse = on
DaemonUser = ecspread
DaemonGroup = ecspread
DebugFlags = { EXIT CONFIGURATION }
RuntimeDir = /var/run/spread
EventLogFile = /var/log/spread/mainlog
EventTimeStamp
DangerousMonitor = false
# Subcluster: west => rh52mgr.vmnet24.example.com
Spread_Segment 10.79.240.255:4803 {
rh52bar2 10.79.240.129
}
For more information about subclusters see “Subclusters”.