Q301310: IIS 5 Common Registry Parameters (1 of 2)
Article: Q301310
Product(s): Internet Information Server
Version(s): 5.0
Operating System(s):
Keyword(s): kbOSWin2000
Last Modified: 29-JUN-2001
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The information in this article applies to:
- Microsoft Internet Information Services version 5.0
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SUMMARY
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This article is part 1 of 2 containing information regarding the common registry
parameters for Internet Information Services (IIS) 5.0.
The Internet Information Server contains the following three registry keys:
- FTP
- WWW (World Wide Web)
- Internet Information Server (IIS)
The registry keys for FTP and WWW use a few similar parameters and values, but
are used independently of each other. The IIS registry key provides registry
parameters and values that are global for the InetInfo process and the server.
The parameters are classified into the following 2 catagories:
- ADMIN CONFIGURABLE - These parameters are best configured using the Admin
tool to take effect immediately. If these parameters are manually configured,
all services should be stopped and restarted.
- CONFIGURABLE - These parameters are optional. Currently no administration
support exists for changing these parameters. If any change is made to such
parameters, all services need to be stopped and restarted.
MORE INFORMATION
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IIS shares a common portion of registry in the following location for the
InetInfo process. These parameters (and their values) are used for global
control of the Internet Information Server.
The parameter location is under the HKEY_LOCAL_MACHINE tree under the following
keys:
\System\CurrentControlSet\Services\InetInfo\Parameters
ListenBacklog REG_DWORD
Range:1 - 250 Default:25
Description: ADMIN CONFIGURABLE
This specifies the WinSock listen backlog for each IP address that the server is
listening on. If many connections per second are being received, the WinSock
listen backlog may become depleted and client?s connections may be refused.
Servers that are under heavy loads may want to set this value to approximately
50.
BandwidthLevel REG_DWORD
Range:0 - 0xFFFFFFFF Default:0xFFFFFFFF
Description: ADMIN CONFIGURABLE
This specifies the amount of bandwidth on the network that the IIS server can
use. The server comes with an automatic bandwidth throttler that makes
intelligent decisions to meet user requirements. This helps to reduce
overloading the network with IIS server activities. For administrators of small
corporate servers, where a single server is used for multiple sites, this helps
to reduce network usage for IIS servers. It is recommended that this parameter
be set from Internet Server Admin Manager; otherwise, the server should be
stopped and restarted for this value to take effect. A special value of
0xFFFFFFFF means that you should not do any throttling.
MemoryCacheSize REG_DWORD
Range:0 - 0xFFFFFFFF Default:10% of Physical Memory
Description: CONFIGURABLE
IIS caches system handles, directory listings, and several BLOBs of
frequently-used data to improve performance of the system. This parameter
specifies the amount of memory in bytes to allocate for such a cache. This
cannot be configured by using Admin Manager. When this parameter is changed, the
server should be stopped and restarted for the changes to take effect. A special
value of 0 means that you should not do any caching. The performance may be low
when caching is shut out. Certain sites that experience a large amount of file
traffic can increase this size if there is sufficient RAM on the system.
DisableMemoryCache REG_DWORD
Range:0 - 1 Default:1 (PWS) 0 (IIS)
Description: CONFIGURABLE
This disables IIS server caching. This cannot be configured using Admin Manager.
When this parameter is changed, the server should be stopped and restarted for
the changes to take effect.
ObjectCacheTTL REG_DWORD
Range:0 - 0x7FFFFFFF, 0xFFFFFFFF Default:30 seconds
Description: CONFIGURABLE
Objects in the memory cache are phased out of the cache if there have been no
references to an object after this period. If the number of data files is
limited or clients only access a small portion of files, increasing this value
may be of benefit (perhaps on the order of fifteen minutes). A value of
0xFFFFFFFF disables the object cache scavenger. Units: Seconds.
UserTokenTTL REG_DWORD
Range:0 - 0x7FFFFFFF Default:15*60 (10 minutes)
Description: CONFIGURABLE
When a request is made to the server, the security credentials for the request
(or the configured anonymous user) are used to create a user token on the server
that the server impersonates when it accesses files or other system resources.
The token is cached so that the NT logon only takes place the first time the
user accesses the system or after the user?s token has fallen out of the cache.
NTLM authentication tokens are not cached. Units: Seconds.
LogFileBatchSize REG_DWORD
Range:1200 - 0xFFFFFFFF Default:64*1024 (64 KB)
Description: CONFIGURABLE
This specifies the batch size for writing the log file. The server caches the
last LogFileBatchSize bytes of data in memory buffers before it dumps the
current buffer and moves on to the next buffer. Such batch processing reduces
the amount of disk traffic that is created by log files. However, if a site
needs the current up-to-date log records to be flushed to the disk, the batch
size can be reduced.
NOTE: For release 1.0 of Gibraltar servers, set this parameter to at least 1200
bytes or the services will crash.
LogFileFlushInterval REG_DWORD
Range:60 - 0xFFFFFFFF Default:5*60 (5 minutes)
Description: CONFIGURABLE
This specifies the interval for flushing out the log file. The server
periodically checks for outstanding log records and flushes them if necessary at
the interval that is specified by this parameter. This is very useful in a
low-volume server environment. In large-volume environments, LogFileBatchSize
takes control of flushing the records after there is a critical mass of log
data. The minimum interval that is permitted is 1 minute. If a value of INFINITE
(0xFFFFFFFF) is specified, the periodic flushing is disabled. Units: Seconds.
MaxPoolThreads REG_DWORD
Range:0 - 0xFFFFFFFF Default:10
Description: CONFIGURABLE
MaxPoolThreads specifies the number of pool threads to create per processor. Each
pool thread watches for the network request and processes the same. Generally,
you should not create more than 20 threads per processor.
PoolThreadLimit REG_DWORD
Range:0 - 0xFFFFFFFF Default:2 * # MB
Description: CONFIGURABLE
PoolThreadLimit specifies the maximum number of pool threads that can be created
in the system. Each pool thread watches for the network request and processes
the same.
MaxConcurrency REG_DWORD
Range:0 - 0xFFFFFFFF Default:0
Description: CONFIGURABLE
This specifies the amount of concurrency that a system should provide. Completion
ports are used for handling IO. In general, you should not have more than one
thread running and conflicting on shared memory or locks. This parameter
specifies how many threads per processor should be allowed to run simultaneously
if there is a pending IO operation. The specific value of 0 allows the system to
make an intelligent choice about the number of threads to use. Any non-zero
value specifies that the system should allow that many threads per processor to
run simultaneously.
ThreadTimeout REG_DWORD
Range:0 - 0xFFFFFFFF Default:24*60*60 (24 hours)
Description: CONFIGURABLE
This specifies the amount of time that an IO processing thread should be
maintained even if there is no IO on the system. In general, when there is no IO
activity and there are no requests outstanding, the server is idle and does not
consume memory. However, if that situation prolongs and exceeds the
ThreadTimeout interval, the thread is killed. Units: Seconds.
UseAcceptEx REG_DWORD
Range:0, 1 Default:1
Description: CONFIGURABLE
Starting with NT 3.51 SP2, there is a new facility that listens and establishes
connections at the server side. AcceptEx provides an inexpensive way to accept
and receive initial chunks of data on a new incoming connection. By default, the
server uses this method to accept new connections. If for experimental purposes
you decide to turn off this fast IO path, this value can be set to 0. However,
setting this value to 0 may cause potential performance degradation.
AcceptExOutstanding REG_DWORD
Range:0-1000 Default:40
Description: CONFIGURABLE
When you use AcceptEx, a certain number of sockets should be maintained to
receive and process new connections. This parameter specifies the number of such
outstanding connections to maintain. Whenever the number of outstanding sockets
falls below this range, the server adds additional sockets to bring it back to
this level.
AcceptExTimeout REG_DWORD
Range:0-0xFFFFFFFF Default:120
Description: CONFIGURABLE
This specifies the time an accept ex socket is allowed to wait for a receive to
complete before the server blows away the long-waiting connection. This helps to
reduce the number of outstanding sockets and therefore conserve the system
memory usage. Units: Seconds.
UseTransmitFile REG_DWORD
Range:0 - 1 Default:1
Description: CONFIGURABLE
This allows the user to disable the use of TransmitFile by the server. This is
useful especially for the NTW version when users have more than one remote
client connected over a slow link, because TransmitFile can tie up resources in
the system during sends.
NonTFBufferSize REG_DWORD
Range:512 - 64K Default:4096
Description: CONFIGURABLE
This is used when TransmitFile is disabled by using the UseTransmitFile registry
key. This allows the user to control the size of the I/O buffers that are used
in the system.
MimeMap Key
Description: CONFIGURABLE
This is a subkey that contains all of the Multipurpose Internet Mail Extensions
(MIME) mappings for the Web servers. Note that each MIME type is a REG_SZ with
the type information as the name of the value with an empty value. The format
for each entry is as follows:
<mime-type>,<file-extension>,<unused>
For example, if the entry is the following
image/gif,gif,,5
when clients ask the Web server for a file that ends with a .gif extension, the
MIME type that is returned to the client is "image/gif".
MinFileKbSec REG_DWORD
Range: 1 - 8192 Default: 1000
Description: CONFIGURABLE
When an IIS server sends a file to the client, a timeout is established for how
long the server will allow the transfer to continue before aborting it. The
timeout that is chosen is the maximum of the following two items:
- The Connection Timeout that is specified in the Admin tool.
- The size of the file divided by the value specified as MinFileKbSecs.
For example, a file size of 100 KB is given a timeout of 100 seconds or the
Connection Timeout if it is greater. Note that the registry name is misleading:
the value is in bytes, not kilobytes (as the name might imply).
CacheSecurityDescriptor REG_DWORD
Range:0 - 1 Default:0
Description: CONFIGURABLE
This value specifies whether security descriptors are cached for file objects. If
this is enabled ( 1 ), IIS retrieves security permissions when caching a file
object and does not need to access the file object to check access rights for
new users. This is only interesting if you have more than one user account (for
example, if you are not using anonymous only). By default, IIS does not cache
the security descriptor and checks the access rights against the file object for
new user accounts.
DebugFlags REG_DWORD
Range: 0 - 0xFFFFFFFF Default:0
Description: INTERNAL ANALYSIS
DebugFlags specifies the bit mask for selectively enabling different checks in a
debug binary of the server common DLL (Infocomm.dll). This bit mask applies to
the common DLL only.
#define DEBUG_ERROR 0x00000008L
#define DEBUG_ODBC 0x00000010L
#define DEBUG_DLL_RPC 0x00000020L
#define DEBUG_GATEWAY 0x00010000L
#define DEBUG_INETLOG 0x00020000L
#define DEBUG_ATQ 0x00040000L
#define DEBUG_DLL_EVENT_LOG 0x00100000L
#define DEBUG_DLL_SERVICE_INFO 0x00200000L
#define DEBUG_DLL_SECURITY 0x00400000L
#define DEBUG_DLL_CONNECTION 0x00800000L
#define DEBUG_DLL_SOCKETS 0x01000000L
#define DEBUG_HEAP_FILL 0x02000000L
#define DEBUG_HEAP_MSG 0x04000000L
#define DEBUG_HEAP_CHECK 0x08000000L
#define DEBUG_MIME_MAP 0x10000000L
#define DEBUG_DLL_VIRTUAL_ROOTS 0x20000000L
Additional query words: iis 5
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Keywords : kbOSWin2000
Technology : kbiisSearch kbiis500
Version : :5.0
Issue type : kbinfo
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