Cisco Cisco Expressway 维护手册
Any changes made on other peers are not reflected across the cluster, and will be overwritten the next time the
master’s configuration is replicated across the peers. The only exceptions to this are some
master’s configuration is replicated across the peers. The only exceptions to this are some
You may need to wait up to one minute before changes are updated across all peers in the cluster.
Adding and Removing Peers From a Cluster
After a cluster has been set up you can add new peers to the cluster or remove peers from it.
Note that:
■
Systems that are configured as peers must not also be configured as neighbors to each other, and vice versa.
■
If peers are deployed on different LANs, there must be sufficient connectivity between the networks to ensure
a low degree of latency between the peers - a maximum delay of 15ms one way, 30ms round-trip.
a low degree of latency between the peers - a maximum delay of 15ms one way, 30ms round-trip.
■
Cluster peers can be in separate subnets. Peers communicate with each other using H.323 messaging, which
can be transmitted across subnet boundaries.
can be transmitted across subnet boundaries.
■
Deploying all peers in a cluster on the same LAN means they can be configured with the same routing
information such as local domain names and local domain subnet masks.
information such as local domain names and local domain subnet masks.
Changing the Master Peer
You should only need to change the Configuration master when:
■
the original master peer fails
■
you want to take the master Expressway unit out of service
Note that if the master fails, the remaining peers will continue to function normally, except they are no longer able to
copy their configuration from the master so they may become out of sync with each other.
copy their configuration from the master so they may become out of sync with each other.
To change the master peer you must log in to every other Expressway in the cluster and change the configuration
master on each peer:
master on each peer:
1.
Log in to the Expressway and go to System > Clustering.
2.
Change the Configuration master to the peer you want to set as the new master (the numbers match against
the Peer IP address fields underneath).
the Peer IP address fields underneath).
3.
Click Save.
4.
Repeat this for every peer in the cluster, ensuring that you select the same new master on each peer.
Note that during this process you may see alarms raised on some peers about inconsistent master peer configuration.
These alarms will be lowered when every peer in the cluster is configured with the new master.
These alarms will be lowered when every peer in the cluster is configured with the new master.
Monitoring the Status of the Cluster
The status sections at the bottom of the Clustering page show you the current status of the cluster, and the time of
the previous and next synchronization.
the previous and next synchronization.
Specifying Peer-Specific Items in Clustered Systems
Most items of configuration are applied via the master peer to all peers in a cluster. However, the following items
(marked with a
(marked with a
†
on the web interface) must be specified separately on each cluster peer.
Note:
You should not modify configuration data that applies to all peers on any peer other than the master peer. At
best it will result in the changes being overwritten from the master; at worst it will cause cluster replication to fail.
Cluster configuration (System > Clustering)
The list of Peer IP addresses (including the peer's own IP address) that make up the cluster has to be specified on
each peer and they must be identical on each peer.
each peer and they must be identical on each peer.
121
Cisco Expressway Administrator Guide