1.2.3 Network traffic between tiers
The next performance item we consider is the network. As illustrated in Figure | -3, the system network connects each tier. By caching as close to the client as we can, significant gains can be achieved by reducing the number of network hops taken while traversing through each of the remaining tiers to the database server and back to the client.
Figure 1-3 Network of servers
Apart from the caching aspects, it is also important that your network design is well thought out and the network is maintained in a healthy state. Many performance problems are caused directly by poorly designed network configurations. Before you engage in any DynaCache tuning exercise, ensure there are no bottlenecks in the network. You should check that:
| Server network cards are configured correctly, meaning they are set to a fixed address, and not auto detect. |
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| All components (routers, switches, IP sprayers, and so forth) are configured and capable of running at the correct network speed. |
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| TCP/IP has been configured correctly, for example, with appropriate time-out and keep-alive settings. |
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| You are not competing with other traffic, such as a WAN, on this network. |
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| The servers are on a separate subnet. |