2.2 Multiple-server Installations
By using at least three servers, one for the MS and two for ESs, you gain the advantage of high availability and load balancing.
High availability is where ESs take over for any other ES or servers that become unavailable. Load balancing is where the testing of endpoints is spread evenly over all of the ESs. A three-server installation is shown in the following figure:
Figure 2-2 Multiple-server Installation
When your network is more complex, you can continue to add clusters as shown in the following figure:
Figure 2-3 Multiple-server, Multiple-cluster Installation
The system configuration area allows you to select default settings for all clusters, as well as override the default settings on a per-cluster basis. See Section 3.0, System Configuration for task-based instructions.
The following recommendations should be followed when configuring your network for best performance results:
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A maximum of 300,000 endpoints per MS (4 GB RAM required)
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A maximum of five ESs per cluster
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A maximum of 3000 endpoints per ES
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There is no inherent limitation in the number of clusters per MS
When these recommendations are followed, the following applies:
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80% of the 3000 endpoints will be tested in 30 seconds or less
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All endpoints are returned to the proper status within 15 minutes after a network recovery (power failure, all endpoints attempting to reconnect, 3000 endpoints per ES)
NOTE:The minimum and recommended hardware requirements are listed in Section 16.8, System Requirements; however, Novell has tested and certified Novell ZENworks Network Access Control on the following systems:
- Dell Xeon 5130, 2 GB RAM, 73 GB Hard drive, 15 k SAS, 3 NICs
- Dell Xeon E5335, 4 GB RAM, 146 GB Hard drive, 15 k SAS, 3 NICs
- Dell Xeon E5335, 8 GB RAM, 300 GB Hard drive, 15 k SAS, 3 NICs
- Dell Dual Xeon E5335, 8 GB RAM, 600 GB Hard drive, RAID 10, 3 NICs, 2 PSU