DBWEB: dbWeb Service Stops Responding During Concurrent Requests
ID: Q152793
|
The information in this article applies to:
-
Microsoft dbWeb, version 1.0
SYMPTOMS
Moderate: Requires basic macro, coding, and interoperability skills.
When the dbWeb Service receives two or more hits at the same time, the
service may stop responding (hang) and display one of the following error
messages:
CGI Error
The specified CGI application misbehaved by not returning a complete
set of HTTP headers. The headers it did return are:
Catch -- dbWebClient
-or-
Request failed
The network connection encountered an error.
Please try again later.
Catch -- dbWebClient
This can occur occasionally when you use the Microsoft Access ODBC driver
(Odbcjt32.dll) to connect to Microsoft Access databases for publishing on a
World Wide Web site using dbWeb 1.0.
CAUSE
When a site has two or more concurrent requests, the dbWeb service spawns a
separate execution thread for each request. When a thread is no longer
used, it must be terminated. When the dbWeb service enters a routine to
clean up unused threads generated by the concurrent requests, and
encounters a deadlock, it will not return from a wait state. This causes
the dbWeb CGI client stub program to time out. This behavior can occur with
the Microsoft Access ODBC driver (Odbcjt32.dll).
RESOLUTION
There are two workarounds for this problem:
- You can use a client/server database such as Microsoft SQL Server as
the back-end for your dbWeb site instead of Microsoft Access for
Windows 95. In general, the ODBC drivers for client/server databases
are optimized to handle concurrent usage more efficiently than the
Microsoft Access ODBC driver.
- You can use a batch file to load AT commands executed by the Windows NT
Server Schedule service to frequently stop and restart the dbWeb
service. To create the AT commands needed to stop and restart the
dbWEb service on a regular basis follow these steps:
NOTE: This workaround assumes you are familiar with Windows NT
services, creating batch files, and using AT command codes.
NOTE: In the following sample code, an underscore (_) at the end
of a line is used as a line-continuation character. Remove the
underscore from the end of the line when re-creating this code.
- Open a text editor, such as Notepad, and open a new file.
- Enter the following lines:
net stop dbwebservice
net start dbwebservice
- On the File menu, click Save As. Locate the root directory of
the server and save the file as Strtstop.bat.
- On the File menu, click New.
- Enter one of the following sets of commands (which are written in
relation to the server. All directories, menus, and services are
referenced on the server, which hosts dbWeb):
- To create a file to load a set of AT commands that stop and
restart the dbWeb service once an hour every day of the month
using the Strtstop.bat:
at 0:01 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 1:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 2:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 3:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 4:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 5:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 6:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 7:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 8:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 9:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 10:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 11:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 12:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 13:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 14:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 15:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 16:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 17:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 18:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 19:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 20:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 21:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 22:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
at 23:00 /every:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,_
17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 c:\strtstop.bat
-or-
- To create a file to load a set of AT commands that stop and
restart the dbWeb service once an hour every day of the week
using the Strtstop.bat:
at 00:01 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 01:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 02:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 03:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 04:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 05:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 06:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 07:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 08:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 09:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 10:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 11:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 12:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 13:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 14:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 15:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 16:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 17:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 18:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 19:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 20:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 21:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 22:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
at 23:00 /every M,T,W,Th,F,S,Su c:\strtstop,bat
- On the File menu, click Save As. Enter Dbwstop.bat as the file name
and note the location where it is saved.
- Switch to Program Manager and open the Main program group.
- Open Control Panel and double-click the Services icon.
- In the Services dialog box, follow these steps:
- Click the Schedule service.
- Click the Start button. This action will start the Schedule
service. It is not started by default.
- Click the Startup button.
- From the Services dialog box, click the Automatic option in the
Startup Types section.
- Click OK to return to the Services dialog box.
- Click Close to return to Control Panel.
- Close Control panel and return to the Main program group.
- Double-click the MS-DOS icon in the Main group to open an MS-DOS
Window.
- In the MS-DOS Window, change directories to the location of the
Dbwstop.bat file created in step 7.
- Run the batch file by typing Dbwstop.bat at the command prompt.
The batch file will echo to the screen that each line was added
as a task.
- Type exit at the command prompt to
close the MS-DOS window and return to Windows NT.
STATUS
Microsoft has confirmed this to be a problem in Microsoft dbWeb 1.0. This
problem no longer occurs in Microsoft dbWeb version 1.1.
MORE INFORMATION
Each command loaded by the Dbwstop.bat file is entered into the Windows NT
Registry. Because each command is a Registry entry, the Dbwstop.bat file is
used only to load AT commands. The Registry values entered are static and
will remain until removed even after the server has been restarted. Setting
the "Schedule Service Startup Type" to Automatic ensures that the Schedule
Service will also restart.
The examples demonstrated in this article establish a schedule of stopping
and restarting the dbWeb service on a periodic basis. An analysis of the
dbWeb site should be performed to determine the best interval for the stop
and restart to occur. The Stop and Restart action only needs about 4
seconds or so on a 66mhz 486 computer with 32mb RAM. Faster hardware should
perform at least as well.
Altering the schedule will require you to make additional entries to the
Dbwstop.bat file for shorter intervals between actions or fewer entries for
longer intervals. You can control the interval by altering the time value
immediately following the AT in the command line. Once you make changes to
the Dbwstop.bat file, you must remove any previous schedule (if any) from
the Registry by typing the following command in an MS-DOS window:
AT /delete
NOTE: The "at /delete" command removes all schedule service entries. If any
scheduled events--unrelated to dbWeb--are set, you need to re-enter them
into the schedule. Once you remove the previous entries, you can run the
Dbwstop.bat file again.
The actions controlled by the Schedule service are performed as background
tasks; they run transparently without any feedback.
REFERENCES
For more information about AT commands, search for "NT Commands," and then
"AT" using the Microsoft Windows NT Server Help Index.
Additional query words:
CGI error failed locked up
Keywords : kberrmsg NpdOthr
Version : 1.0
Platform : WINDOWS
Issue type : kbprb
|