WampServer

Hi,

I run a local server using WAMP (Apache Version 2.4.9 Win32, PHP Version 5.5.12, MySQL version 5.6.17) on Windows 7 (with administrator rights).

Sporadically (maybe once every three hours, but very unpredictable), the connection to one of the client dies with the following message in the apache error log (status 255):

[mpm_winnt:notice] [pid 668:tid 328] AH00354: Child: Starting 64 worker threads.
[mpm_winnt:notice] [pid 728:tid 412] H00428: Parent: child process 668 exited with status 255 -- Restarting.
[mpm_winnt:notice] [pid 728:tid 412] AH00455: Apache/2.4.9 (Win32) PHP/5.5.12 configured -- resuming normal operations
[mpm_winnt:notice] [pid 728:tid 412] AH00456: Apache Lounge VC11 Server built: Mar 16 2014 12:13:13
There are no error messages in the php error log.

In the windows event log I get the following messages:

Faulting application name: httpd.exe, version: 2.4.9.0
Faulting module name: ntdll.dll, version: 6.1.7601.18798, time stamp: 0x5507b3e0
Exception code: 0xc0000005
Fault offset: 0x0002e3be
Faulting process id: 0x29c
Faulting application start time: 0x01d16af6d52655e1
Faulting application path: C:\wamp\bin\apache\apache2.4.9\bin\httpd.exe
Faulting module path: C:\Windows\SysWOW64\ntdll.dll


And further:

Event Name: APPCRASH
Response: Not available
Cab Id: 0

Problem signature:
P1: httpd.exe
P2: 2.4.9.0
P3: 532585f0
P4: ntdll.dll
P5: 6.1.7601.18798
P6: 5507b3e0
P7: c0000005
P8: 0002e3be
P9:
P10:


When this happens the client becomes unresponsive but immediately starts to work again after some seconds.

In total I have 24 parallel clients that interact with the server. Again, it only happens sporadically to single clients.

I found some old threads related to this issue, but often related to other "Faulting Modules".

Can someone help me on this issue? I am completely lost with regards to whether this is related to a (i) php issue, (ii) windows issue (iii) apache issue or (iv) wamp issue and how to attempt to solve it.

Hi,

Depending on the version of Windows, the maximum number of simultaneous incoming connections, ie from other machines, drives, printers, varies.
Windows NT4 Workstation, Windows 2000 Professionnal, Windows XP Professionnal, Windows Vista : 10
Windows 7, Windows 8, Windows 10 : 20
All Windows Server versions: unlimited

This limitation to 10 or 20 only applies to incoming connections.

As you wrote : « In total I have 24 parallel clients that interact with the server. » There may come a time when you exceed the 20 incoming connections and the server disconnects.

To see the limits your Windows has, in a Command line windows type:
net config server

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Documentation Apache - Documentation PHP - Documentation MySQL - Wampserver install files & addons

Dear Otomatic,

Thank you!

That would mean it is a problem with the windows OS and not the Apache/PHP code etc.?
(Although it also happened once with only 20 clients, can that be?)

Can I just increase this limit in windows 7 to fix this problem?



Edited 3 time(s). Last edit at 02/21/2016 11:23AM by grueb.

No you would have to install WAMPServer on a Windows Server OS rather than a desktop OS which is configured to be a server and therefore these limits are not the same.

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(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>
Read The Manuals Apache -- MySQL -- PHP -- phpMyAdmin
Get your Apache/MySQL/mariaDB/PHP ADDONs here from the WAMPServer alternate Repo
-X-X-X- Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-

Hi,

> Can I just increase this limit in windows 7 to fix this problem?
Impossible.

Even if you can modify the registry key that contains the limit of 20, there is another key which verifies the content of the first key. One would have to change the two keys simultaneously and it is not possible.

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Documentation Apache - Documentation PHP - Documentation MySQL - Wampserver install files & addons

Dear Otomatic,
Thanks for clarifying!

Is there any way to see the maximum number of (simultaneous) incoming connections in real time on the windows machine where the wamp server is running?

I would really like to make sure that this is the cause of the problem and replicate it systematically, to rule out any other potential issues (as I said, it sometimes also happens with only 20 clients).

Hi,

Unfortunately, there is no direct command to display or return the number of incoming connections. Even netsh or netstat does not allow it.

Must be "programmed" using the function NetServerGetInfo of Netapi32.dll API. In SERVER_INFO_102, the structure that is returned, the sv102_users field contains that number of connections.

> as I said, it sometimes also happens with only 20 clients).
Not counting incoming Internet connections that can occur randomly.

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Documentation Apache - Documentation PHP - Documentation MySQL - Wampserver install files & addons

(as I said, it sometimes also happens with only 20 clients).

Remember that Apache is not the only thng on your Windows Desktop System that has the potential to consume incoming connections.

This is one of the main reasons why WAMPServer never actively suggests it is a good idea to use WAMPServer as a LIVE server. There is no reason why Apache should not be used as a LIVE web server obviously, it's prime use is exactly that.

However a Windows Desktop system is not an environment suited to this, its configuration is based on what a single user is likely to need to do.

Also as Microsoft sells a Server OS, the Desctop OS is limited so that you cannot encourage a £100 OS to do the work of a £1000 OS.

If you want this to work, you will need to installed Windows Server and run WAMPServer on that.

---------------------------------------------------------------------------------------------
(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>
Read The Manuals Apache -- MySQL -- PHP -- phpMyAdmin
Get your Apache/MySQL/mariaDB/PHP ADDONs here from the WAMPServer alternate Repo
-X-X-X- Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-

Yes, I see that – thank you for your responses!

I agree that windows 7 (personal version) is not a good choice for this. Unfortunately I am not in charge with regards to the setup and just have to deal with it.

Therefore, I just want to make sure that the limitation of windows 7 is actually the root of the problem and not something with my coding or the server setup.
Since there are no errors in the PHP log and it only happens sporadically with the posted error messages – can I be certain that it has to do with the built-in limitation of incoming connections of windows 7?

Or could it still be something unrelated to the OS?
(i.e. related to PHP, my code, or the apache setup)


Sorry for repeatedly asking – I just want to make sure that this is indeed the cause of the problem.

And the reason we are not directly answering that specific question is that we cannot possibly know FOR SURE.

We cannot see your system, we cannot play with your system, so how can we possibly KNOW FOR SURE.

However these connection limits are well known and documented. I once spent a fruitless couple of days attempting to increase this limit and failed completely, so gave up

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(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>
Read The Manuals Apache -- MySQL -- PHP -- phpMyAdmin
Get your Apache/MySQL/mariaDB/PHP ADDONs here from the WAMPServer alternate Repo
-X-X-X- Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-