![]() |
![]() |
![]() |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
![]() |
![]() |
To access the contents, click the chapter and section titles.
Oracle Performance Tuning and Optimization
Network DesignAs you have seen, there are only a few things you can do in the operating system and the application to improve network efficiency. The majority of the performance improvements are accomplished by reducing the load on any particular component in the network. Primarily, you can improve performance by subnetting, that is, by segmenting the load among several different segments. The alternative to increasing the bandwidth of the network is to purchase faster network hardware. By upgrading from 10Base-T to 100Base-T, you instantaneously see substantial improvement in bandwidth. In many cases, your network wiring may already be able to handle the faster 100Base-T networks. You should use some sort of network load monitor on a regular basis to determine whether you are near the limits of the network. Do some trend analysis and try to determine where the majority of network traffic is originating. You may discover that certain operations (such as backups or loads) are using a large percentage of the network bandwidth and should be segmented off the main network. If you keep the network usage within limits, the network should not be a bottleneck. As mentioned in the last chapter, as you near the limits of an Ethernet or FDDI network, the number of collisions increases exponentially. It is a good idea to segment these types of networks so that you never exceed 60 to 70 percent of the available bandwidth. Bandwidth ConsiderationsThe bandwidth of the network represents the theoretical maximum of data throughput that can be achieved by the network medium. For Ethernet, this is 10 megabits/second. By using larger packets, you can achieve a maximum throughput much closer to the theoretical limit than you can with small packets. The more computers that try to access the network, the less likely you are to reach the maximum throughput because of the increased likelihood of collisions. When your network load reaches 60 to 70 percent of the bandwidth of the network, you will begin to see a fairly high collision rate. At this point, the performance of the network starts to be affected. If possible, try to keep the network usage below 60 percent. Of course, there are peak times during which the network sees high usage, but in general, try to keep the load in this range. The only available way to increase the bandwidth of the network is by upgrading to a faster type of network hardware, such at 100Base-T, fiber optics, or ATM. The available bandwidth of the network is based on the type of hardware you are using. The speed of the LAN segment is based on standards. By standardizing the speeds, you can add different hardware components supplied by different hardware vendors and they will all work on your network. Segmenting the NetworkThe best way to reduce the amount of traffic on your network is to use subnetting or segmenting. Subnetting involves breaking the network into smaller individual LAN segments. By breaking the LAN into smaller segments, you divide the network load among the segments and reduce the load on each individual segment. By reducing the load on the individual segments, you reduce collisions and avoid performance degradation. When the network is segmented, you may have to deploy routers. Routers are used to pass network packets between different subnets. Although most operating systems can do routing, doing so uses some CPU resources. You should avoid routing on your database server. Hardware routers are also available; these routers bypass the operating system and can perform routing tasks with very little overhead. Hardware routers can route network packets much faster and more efficiently than any operating system. Bridges, Routers, and HubsBridges, routers, and hubs are all needed to keep a network running. Routers are used to route data back and forth between different subnets; bridges are used to bridge between networks; and hubs are used simply as electrical repeaters. All these elements may be in use in your installation. Be sure that your routers and bridges are not a source of delays. Especially if you employ a router or a bridge that uses a general-purpose OS for routing and bridging functions, you may see substantial delays in these services. A special-purpose hardware router or bridge always provides significant performance gains over an OS-based router or bridge. SummaryTo optimize your network, you should look at both the software and the hardware. To optimize the network software, there is typically not much you can do. By reducing unnecessary network protocols and applications, you can streamline the operation of the network; there is not much else you can do to enhance its performance. To optimize the network hardware, there is not very much you can do either. The best thing to do is simply monitor the network load and break the network into smaller segments if necessary. By subnetting the network, you can reduce the load for each segment, thus avoiding network bottlenecks.
|
![]() |
Products | Contact Us | About Us | Privacy | Ad Info | Home
Use of this site is subject to certain Terms & Conditions, Copyright © 1996-2000 EarthWeb Inc. All rights reserved. Reproduction whole or in part in any form or medium without express written permission of EarthWeb is prohibited. Read EarthWeb's privacy statement. |