Astaro Deployment Guide
High Availability Options
© 2011 Astaro GmbH & Co. KG – a Sophos company. Subject to change without notice.
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Extending a Cluster
After some time operating the cluster, performance of the system may decrease. This happens usually either by
growing amounts of users the system must support, or use of new features, for example by adding optional
subscriptions. Astaro clusters are highly scalable and adding additional nodes to a cluster is done in minutes: In
Web Admin you only need to set the high availability status to “Automatic configuration” and select the
appropriate synchronization interface.
After applying these changes, the new node will automatically be added to the cluster as an additional worker
node.
Adding an additional node to a cluster
Integrated Load Balancing
In a clustered Astaro HA environment the load is evenly distributed between the participating cluster nodes.
Astaro’s patent pending load balancing technology automatically makes use of all hardware resources in a
cluster, whereas the master node takes the responsibility to distribute the load between the slave and worker
nodes. Even new worker nodes are immediately assimilated and the master node seamlessly adds the
additional resources to the cluster. Additionally, it is worth noting that when building a cluster with more than
three nodes, the master is dedicated to act solely as the central load balancing and synchronization system and
does not process any traffic data itself anymore.
Distributed Network Traffic
The following list includes the types of network traffic that is distributed to the cluster nodes:
IPSec
IPS
FTP
HTTP
POP3
SMTP
