WindowsNT4.xx Server and Windows9x Workstations Due to the specific nature of Windows NT4(any service pack) locking
mechanics interacting with Windows95/98 locking, the following settings are recommended
within the FIX product to optimize multi-user performance. These settings may be accessed
and modified provided the user is logged into FIXPro with a coordinator sign on level
(User level zero through ten). Select "File", "System Control" from the main menu. Once this is
open, click on "Configure" and "Advanced" to access the settings.
Ensure the settings are as below:
Further to these settings, Workstation/Server Registry settings affect
performance.
Auto Save - Disabled. This
setting is used to control buffer caching of data locally on the workstation. Although in
some networks, this is deemed to be a performance enhancement, using this configuration,
Windows NT implements opportunistic locking, which Windows95/98 do not support. When
enabled, the workstation's memory will buffer records while changing them, and reading
them. By buffering these records and using standard locking mechanics, most servers with
the records locked, will respect the workstations changes and locks. Windows NT does not
strictly adhere to the standards, and attempts to improve performance by performing an
'OpLock' when a simple 'Lock' is requested. See below for an explanation of 'OpLock' and technical bugs/solutions from Microsoft.
When using network servers that adhere to the standards of 'Locking', this should be
'Enabled'. Default Transaction Type - Normal.
This setting is used to control the default locking mechanics for database record
selections when not specifically programmed as 'Transactions'. This is called an implicit
transaction. The default locking for implicit transactions is to a 'Read/Write' lock on
all records until the entire command is complete. To optimize commands and 'Read' lock for
such commands, this setting for 'Read' locks will lock a number of records and then
release them on a buffered basis. With the Windows NT server, these releases of locks, and
re-locking of new groups of locks is converted to 'OpLocks', thus affecting performance.
For network servers that strictly adhere to the standards of 'locking', use 'Read'. Auto Re-Try - Disabled. This setting
is used to have the workstation attempt to lock and then re-try if the server fails to
lock a record the first and subsequent attempts. The number of automatic re-tries is
controlled by a setting 'Transaction Retries' in the file 'config.db'. This is done
automatically by the workstation operating system, and hence is done very quickly. When
this is performed by the operating system (Windows 9X), the FIX product does not respond
to the user that a lock attempt has failed, until such time as the number of 'Transaction
Retries' has been exceeded. When these maximum number of locking attempts has failed, by
the operating system, then the user sees a message "Database locked. Pls wait".
Once this message has been displayed, the FIX system attempts the lock again. When using
Windows NT server, the server converts the locks on all the above occasions to 'OpLocks',
and processes them according to the 'OpLock' methodology. For network servers that
strictly adhere to the standards of 'locking', Enable this setting to ensure the users
know that their workstations are not Hung while processing large updates to the
database. Advanced Settings
for Windows NT Server with Windows 9X Workstations.
OpLock
FIX multi user systems use a file based sharing system to provide and Entity Set
Relational SQL Database system. This file system opens the physical files in a non -
exclusive method, or in program terms 'Deny none' method. Windows NT server will translate
these file accesses depending upon the file's number of users into OpLock. Microsoft has
documented the enhancement on their web
site (http://support.microsoft.com/support/kb/articles/Q129/2/02.asp). This
enhancement was originally designed to provide better internet performance for their web
server software, and call the 'Common Internet File System' (CIFS protocol was introduced
to support rich, collaborative applications over the Internet in 1996). When Windows95
originally came out, it's network support for Windows NT was contained in files (
VNETSUP.VXD & VREDIR.VXD both dated 07/11/95 and updated 08/24/96 as per OSR1 ). This
upgrade made original Windows95 the equivalent in terms of networking with Windows 95
ORS2). The update improved FIX performance by 15% ( 225/finds/sec on 1100 records using
Pentium Workstations/10mb Ethernet/PowerEdge1300Dell Servers). Subsequent updates
regarding these drivers were made available from Microsoft as file VRDRUPD.EXE.
File name Version Date/Time Size Destination folder
---------------------------------------------------------------------
Vredir.vxd 4.00.1116 6/2/97 11:16a 156,773 Windows\System
Vnetsup.vxd 4.00.1112 5/30/97 11:12a 17,595 Windows\System
HKEY_LOCAL_MACHINE
\System\CurrentControlSet\Services\VxD\VREDIR\DiscardCacheOnOpen=1
Server
Registry Entries
Several specific entries in the server's registry can affect this enhancement. The
following registry entries have provided 'performance test' of 225 finds/sec using this
configuration
Lanman Server - Cut and copy the below
entries into two files lmserver.reg and lmwork.reg. Use Regedit to import these registry
files into your server's registry.
REGEDIT4
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters]
"CachedOpenLimitt"=dword:00000000
"EnableOplocks"=dword:00000000
REGEDIT4
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters]
"UseLockReadUnlock"=dword:00000000
"UseOpportunisticLocking"=dword:00000000