Release 2 (9.2) for Windows
Part No. B10163-01
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Oracle9i Database Platform Guide
Release 2 (9.2) for Windows Part No. B10163-01 |
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This chapter describes how to tune the Windows Server operating system to ensure that your Oracle9i database is running in the best possible environment.
This chapter contains these topics:
Reduce Priority of Foreground Applications on Server Console
Close All Unnecessary Foreground Applications
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Note: For the sake of brevity, this discussion uses the collective term Windows Server when a statement applies to Windows 2000 Server and Windows NT Server. |
Windows Server operating systems offer considerably fewer tuning adjustments than UNIX. This difference constrains systems administrators when they try to optimize Windows Server performance, but it also makes Windows Server easier to use.
There are still ways, however, to make Windows Server a better application server environment for Oracle9i database. Most of the operating system specific procedures described in this chapter enable Oracle9i database to reserve more system resources, such as CPU, memory, and disk I/O.
In addition, because Oracle9i database is a high-performance database management system that effectively uses resources of your Windows computer, it should not also serve as any of the following:
Primary or backup domain controller
File or print server
Remote access server
Router
These configurations consume network, memory, and CPU resources. In addition, the Windows computer that is running your Oracle9i database should not be locally accessed with a high frequency or intensively used for local user processing, unless it has enough resources to accommodate all this activity.
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Note: Information presented in this chapter does not apply to Oracle9i database installations on Windows NT Workstation. It does apply to Oracle9i database installations on Windows NT Server and Windows NT Server 4.0, Enterprise Edition. Windows NT Server 4.0, Enterprise Edition includes capability for using additional products. One such product is Microsoft Cluster Server, which is required to implement Oracle Fail Safe. |
One of the settings provided by default during installation of Windows Server gives interactive foreground applications priority over every background process. To prevent foreground applications on the server console from taking excessive processor time away from Oracle9i database, you can reduce priority for foreground applications.
Choose Start > Settings > Control Panel.
Double-click System.
The System Properties dialog appears.
Choose the Advanced tab.
Click Performance Options...
The Performance Options dialog appears.
Select Background services.
Click OK to close the Performance Options dialog.
Click OK to close the System Properties dialog.
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Note: The procedures for Windows XP 64-Bit Edition Version 2003 and Windows Server 2003 use Processor Scheduling on the Advanced tab, but are otherwise similar to that for Windows 2000. See Appendix G, " Oracle9i Database for 64-Bit Windows" for more information. |
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click System.
The System Properties dialog appears.
Choose the Performance tab.
Move the Application Performance Boost slider to None.
Click OK.
Exit the Control Panel.
Windows memory manager divides up system memory into three different pools described in Table 9-1.
Table 9-1 Windows Server Memory Shares
| Pool | Percent of Total Memory |
|---|---|
| Kernel and other system services | 9% |
| File Cache | 41% |
| Paged Memory | 50% |
Windows Server memory manager tries to balance each application's usage of memory by dynamically paging memory between physical RAM and a virtual memory paging file. If an application is particularly memory-intensive (like Oracle9i database) or if a large number of applications are running concurrently, then combined memory requirements of the applications may exceed physical memory capacity.
The large proportion of memory reserved for file caching (41%) can be quite beneficial to file and print servers. But it may not be advantageous to application servers that often run memory-intensive network applications. A Windows Server file cache is particularly unnecessary for Oracle9i database, which performs its own caching through System Global Area.
You can reset the Windows Server memory model from the default file and print server, with its large file cache, to a network applications model, with a reduced file cache and more physical memory available for Oracle9i database.
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Network and Dial-up Connections.
Double-click Local Area Connection.
The Local Area Connection Status window appears.
Click Properties.
The Local Area Connection Properties window appears.
Select File and Printer Sharing for Microsoft Networks.
Click Properties.
The File and Printer Sharing for Microsoft Networks Properties window appears.
Select Maximize data throughput for network applications.
Click OK to close the File and Printer Sharing for Microsoft Networks Properties window.
Click OK to close the Local Area Connection properties window.
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Network.
The Network dialog appears.
Choose the Services tab.
In the Network Services list, select Server and click Properties.
Select the radio button for a network applications configuration and choose OK.
Click OK on the Network dialog.
Exit the Control Panel.
Restart the system for changes to take effect.
After you have significantly reduced the file cache as described in "Configure Windows Server to Be an Application Server", you can retrieve additional physical memory for Oracle9i database by disabling services not needed for core operating system functionality. Unnecessary services include:
License Logging Service
Plug and Play
Remote Access Autodial Manager
Remote Access Connection Manager
Remote Access Server
Telephony Service
Consult with your systems administrator to identify other unnecessary services.
Do not disable any of the following services:
Alerter
Computer Browser
EventLog
Messenger
OracleServiceSID
OracleHOME_NAMETNSListener
OracleStartSID (Oracle8 release 8.0.6 and earlier)
Remote Procedure Call (RPC) Service
Server
Spooler
TCP/IP NetBIOS Helper
Workstation
To disable unnecessary services:
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Administrative Tools.
The Administrative Tools window appears.
Double-click Services.
The Services dialog appears.
Select the service to disable.
Click Startup.
The Service dialog appears.
Select Disabled in the Startup Type field.
Click OK.
Exit the Control Panel.
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Note: If you are using Windows NT, then you can access the Services dialog from the Control Panel. |
Remove all unnecessary network protocols on Windows so that processing time can be concentrated on servicing only critical protocols.
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Network and Dial-up Connections.
The Network and Dial-up Connections window appears.
Right-click the Local Area Connection icon for the connection you want to adjust and click Properties.
The Local Area Connection Properties dialog appears.
Identify which protocols are necessary for server functionality. Oracle Corporation recommends you use TCP/IP as the sole network protocol.
Select unneeded network protocols and click Uninstall.
Click Yes in the confirmation dialog.
Repeats Steps 4 and 5 until only necessary protocols remain.
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Network.
The Network dialog appears.
Choose the Protocols tab.
Identify which protocols are necessary for server functionality. Oracle Corporation recommends you use TCP/IP as the sole network protocol.
Select unneeded network protocols and click Remove.
Click Yes in the confirmation dialog.
Repeats Steps 4 and 5 until only necessary protocols remain.
Exit the Control Panel.
If multiple protocols must be installed on the server, you can give the protocol most frequently used by Oracle9i database highest priority by resetting the network protocol bind order.
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Network and Dial-up Connections.
The Network and Dial-up Connections window appears.
Right-click the Local Area Connection icon for the connection you want to adjust and click Properties.
The Local Area Connection Properties dialog appears.
Choose Advanced > Advanced Settings...
The Advanced Settings dialog appears.
Choose the Adapters and Bindings tab.
If the primary Oracle9i database protocol is not at the top of the list, select it.
Click the up arrow until the Oracle9i database protocol is at the top of the list.
Click OK.
Choose Start > Settings > Control Panel.
The Control Panel window appears.
Double-click Network.
The Network dialog appears.
Choose the Bindings tab. The Bindings tab appears:
Select all services from the Show Bindings list.
Double-click Server to expand the list of currently installed services.
All available protocol adapters appear:
If the primary Oracle9i database protocol is not at the top of the list, select it.
Click Move Up until the primary protocol is at the top of the list.
If multiple network interface cards (NICs) are installed, expand each protocol and move the NIC used most often by Oracle9i database to the top of the list.
Click OK to save the changes.
Exit the Control Panel.
Restart Windows Server to enable the new changes.
Microsoft releases operating system patches, called Service Packs, on a quarterly basis. Service Packs are collections of bug fixes and product enhancements to the basic Windows Server release. In general, apply Service Packs as soon as it is safe to do so, since they fix bugs and can improve Windows Server performance or functionality.
While Service Packs are supposed to fix bugs, there have been reports (for example, the initial release of Windows NT Server 4.0 Service Pack 2) of bugs within the patch updates themselves. In general, it is safest to wait a few weeks after a Service Pack is released before implementing it. This allows time for other field sites to report any problems with the SP release.
The latest Windows Server Service Packs may be downloaded as self-extracting archives from http://support.microsoft.com
Unless there are assurances that the Service Pack works without flaws on Windows Server, choose to create an Uninstall directory. This enables the Service Pack to be removed and the original configuration to be restored.
Service Pack files overwrite similarly-named files in the previous Windows Server configuration. However, Service Pack files can be overwritten in turn by setup programs that copy files from the original installation media.
For example, installing a new network protocol or printer driver usually requires copying files from original Windows Server installation media. When Service Pack files are comprehensively or selectively overwritten, the Service Pack must be re-applied.
Compared to CPU and memory speeds, hard disk drives are extremely slow. Now that hard disk drives are relatively inexpensive, Oracle Corporation recommends that Windows Server use logical volumes comprised of striped physical disks. Data striping is an effective means of reducing the impact of relatively slow hard drives by distributing file I/O across a number of hard drives simultaneously.
Striping data across a number of disks is one example of a redundant array of inexpensive disks (RAID). There are several different types of RAID, also referred to as RAID levels, ranging from high performance to high reliability. The three most common RAID levels in Oracle9i database installations are RAID-0, RAID-1, and RAID-5. Descriptions of each RAID level follow Table 9-2, which shows each level's read and write penalties.
Table 9-2 RAID Levels in Oracle9i Database Installations
| RAID Level | Read PenaltyFoot 1 | Write PenaltyFoot 2 |
|---|---|---|
| 0 (Disk Striping) | 1:1 | 1:1 |
| 1 (Disk Mirroring) | 1:1 | 2:1 |
| 0 + 1 | 1:1 | 2:1 |
| 5 (Distributed Data Gathering) | 1:1 | 4:1 |
RAID level 0 enables high-performance, nonfault tolerant disk striping. Multiple physical hard disks are aggregated into a logical whole, either by a disk controller or through the operating system (for example, Windows 2000 Server striped volumes). Data operations against the logical volume are broken down into as many chunks as there are physical drives in the array, making simultaneous use of all disks. Given identical hard disks, if one hard disk has a throughput rate of DISKRATE operations/second, then a RAID 0 logical volume has a rate of:
(DISKRATE * [number of physical drives in array]) operations/second
The downside of RAID 0 is its lack of fault tolerance. If one disk in the logical volume fails, the whole volume fails and must be restored from a backup.
RAID level 1 enables fault tolerant disk mirroring with some chance of a performance penalty. Essentially, every write to a mirrored disk is duplicated on another drive dedicated to this purpose (the mirror drive). If the mirrored disk fails, the mirror drive is brought online in real time. After the faulted drive is replaced, the mirror configuration can be reestablished.
The read penalty for RAID level 1 is nominally 1:1, but it may benefit from split reads on some controllers. When the controller knows which mirror can be accessed fastest, for example, it can lower seek times by directing I/O operations to that disk.
RAID level 0+1 enables mirroring of an array of striped hard disks. This is a blend of RAID 0 and RAID 1, offering high-performing fault tolerance.
RAID level 5, also known as disk striping with parity, eliminates the costly requirement to mirror. In RAID 5, multiple hard disks are aggregated into a striped logical volume, similar to RAID 0, but each drive contains parity information such that any single drive failure is tolerated. With one failed drive, a RAID-5 system can allow continued access to data, although access times are greatly reduced due to on-the-fly rebuilding of bytes from parity information. RAID-5 solutions usually allow hot-swapping of faulty drives with replacements, triggering a rebuild of the failed drive's data onto the replacement from parity information.
The write penalty of 4:1 results from 2 reads and 2 writes during parity calculation.
If there are enough physical disks in Windows Server, create at least two striped volumes (in addition to a standalone hard disk or striped volume for the operating system). One striped volume can be used for sequential data access, and the other can be used for random data access.
Oracle9i database redo logs and archived redo logs, for example, are written in sequential order. Because of reduced head movement, hard disks perform best when reading or writing sequential data.
Oracle9i database data files, however, are usually accessed in random order. Random access in a hard disk results in significant head movement, translating to slower data access.
Unless redo logs are separated from datafiles (at physical device level), undo file I/O contention may result, increasing access times for both types of files.
Some virtual memory paging is likely even if Oracle9i database is the only network application running on Windows Server, because Windows Server memory manager will attempt to move seldom-used pages to disk to free up more physical memory for hot pages.
Multiplexing the Windows Server virtual memory paging file is a good strategy to boost overall system performance. Splitting the paging file onto at least two different physical volumes (or logical volumes as long as underlying physical volumes do not overlap) provides a significant performance boost to virtual memory swapping operations.
Even though this is a good technique to increase speed of virtual memory paging, too much paging activity is still a performance hit and should be corrected by adding more RAM to the server.
Oracle Corporation recommends that total combined size of your page files be at least equal to physical RAM on your computer. Configurations where combined size is two to four times the size of physical RAM are not uncommon. Minimize paging as much as possible. But situations in which the operating system runs out of or low on paging space are to be avoided at all costs. Adequately-sized paging files spaced across physical disks spread out I/O most efficiently, because the operating system spreads paging evenly across page files.
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Note: Internal read/write batch size for Windows is 4K. |
Once procedures in previous sections have been applied, remember to close any unnecessary foreground applications. First, remove all applications from Startup folders of Windows Server console operators. Second, minimize the window when executing long-running scripts from a command prompt, so that Windows Server can focus on the operation and not on a flood of window repaint messages. Third, disable screen savers, which can quickly saturate the CPU. If a screen saver must be run, choose Blank Screen, which uses the least amount of processing time.
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 Copyright © 2003 Oracle Corporation All rights reserved |
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