os-windows/5108: When run as a Windows "Service," can fail to autostart, hanging the whole system

[Jack Repenning <ja...@informix.com>]

>Number:         5108
>Category:       os-windows
>Synopsis:       When run as a Windows "Service," can fail to autostart, hanging the whole system
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Oct  6 11:50:00 PDT 1999
>Last-Modified:
>Originator:     jackr@informix.com
>Organization:
apache
>Release:        1.3.9
>Environment:
Windows NT Workstation 4.0sp4
Binary distribution of Apache, from www.apache.org
Other services running:
Albd
Alerter
Apache
Browser
ClipSrv
DHCP
HCLInetd
HCLNFS
LanmanServer
LanmanWorkstation
LmHosts
Messenger
Mvfs
NetBIOS
NetBT
NetDDE
NetDDEdsdm
Netlogon
ParVdm
Parallel
ProtectedStorage
RPCLOCATOR
RasArp
RasAuto
RasMan
RemoteAccess
Replicator
TimeServ
bh
nmagent
ol_mpjackr
>Description:
First observed in 1.3.6 (my first Apache ever); confirmed in 1.3.9.

When run as an autostarted service, Apache can fail to start, virtually 
hanging the system (each mouse-click takes one to three _minutes_ to resolve).

Cause: as of SP4, a service needs to specify what other services 
need to be started before it.  As of WinNT/4.0sp4, Windows is no longer reliably 
getting this right unless you provide the hints.  This won't cause trouble for everyone, 
it might not even cause trouble for you every time, because the new start order is 
something rather like random, unless you provide the hints
.  For reference, see the 
Microsoft web-site (which, in standard Microsoft style, says "SP4 changed things; 
ask your application vendor to fix their application"):
< http://support.microsoft.com/support/kb/articles/Q197/2/86.ASP >

>How-To-Repeat:
Repeatability is hard: lacking the DependOnService hint, the start order 
seems to be pretty much random - probably a function of system load, mix of
other things starting at the same time, etc.  In my experience, anyway, if
a given system is susceptible to the problem, then it's 100% repeatable:
reboot the system, try to log in, it essentially hangs (each mouse-click
takes several _minutes_ to resolve, many minutes after the boot up you begin 
to get "can't start" complaints from many services; system remains hung
indefinitely.

In this state, with much patience, it should be possible to get to the
Services control panel and disable Apache.  You'll still have to reboot
to clear the behavior.
>Fix:
The hints go into the registry entry
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Apache
key "DependOnService"

The value is of type REG_MULTI_SZ.  If you're making the entry by hand, it's 
easiest to use regedt32 (which includes an editor for this data type).  Create the 
key if it doesn't already exist, and give it the three values (one per line, order not 
important, case not important): TcpIp, RpcSs, and Afd.

(I'm not equally sure of all three of those entries: I'm quite sure Apache needs TcpIp, 
but I'm also quite sure that's not enough.  I got the other two by comparing to other 
services that also need TcpIp; I kind of doubt that Apache needs Rpc, actually, and 
I have no clue what Afd is, to tell the truth.  But the problem remains with TcpIp 
only, and goes away with all three, so there you go.  The only danger in specifying 
too many would be if you have some reason not to start one of them, or it fails; then 
Apache would never even try to start.)

If you're doing it by script, put this into some file whose name ends in ".reg", such as 
"Apach.reg" (leave out the "Begin/End" stuff):
>Audit-Trail:
>Unformatted:
[In order for any reply to be added to the PR database, you need]
[to include <ap...@Apache.Org> in the Cc line and make sure the]
[subject line starts with the report component and number, with ]
[or without any 'Re:' prefixes (such as "general/1098:" or      ]
["Re: general/1098:").  If the subject doesn't match this       ]
[pattern, your message will be misfiled and ignored.  The       ]
["apbugs" address is not added to the Cc line of messages from  ]
[the database automatically because of the potential for mail   ]
[loops.  If you do not include this Cc, your reply may be ig-   ]
[nored unless you are responding to an explicit request from a  ]
[developer.  Reply only with text; DO NOT SEND ATTACHMENTS!     ]


>>>>>>>>>Begin Apache.reg<<<<<<<<<
REGEDIT4

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Apache]
"DependOnService"=hex(7):54,63,70,49,70,00,41,66,64,00,52,70,63,53,73,00,00
"DependOnGroup"=hex(7):00
>>>>>>>>>End Apache.reg<<<<<<<<<

Double-click that, and the resource will be created.