[xmail] XMail Win32 threads limit
Since a week we could note a massive (and abnormal) smtp connections in our XMail server (XMail 1.25 Win32 on Windows 2000 Server). After many adjusts in XMail threads to support this DDOS, we could note an interesting thing: Windows 2000 Server does not support more than 1800 threads (counting all kind, pop3 threads, smtp threads, mailer threads, etc). After +-1800 threads, XMail.exe is still there but not answering anymore. Could others XMail Win32 users confirm this value (1800) ? Regards Edinilson - ATINET-Professional Web Hosting Tel Voz: (0xx11) 4412-0876 http://www.atinet.com.br - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] Re: XMail Win32 threads limit
I have not noticed this specifically with xmail, but I have noticed this with other applications. I wrote a very simple test application once (that did nothing but spawn threads which sat idle for 5 minutes, then exited). The count was right around 1800 when the application became unable to spawn additional threads - when some of the spawned threads exited, the application was then able to spawn additional threads. Edinilson - ATINET wrote: Since a week we could note a massive (and abnormal) smtp connections in our XMail server (XMail 1.25 Win32 on Windows 2000 Server). After many adjusts in XMail threads to support this DDOS, we could note an interesting thing: Windows 2000 Server does not support more than 1800 threads (counting all kind, pop3 threads, smtp threads, mailer threads, etc). After +-1800 threads, XMail.exe is still there but not answering anymore. Could others XMail Win32 users confirm this value (1800) ? Regards Edinilson - ATINET-Professional Web Hosting Tel Voz: (0xx11) 4412-0876 http://www.atinet.com.br - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED] - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] Re: XMail Win32 threads limit
Its not an os limit, more a 'process stack size' problem This problem is not OS dependent (even if the max number of threads = could be different from one to another) Xmail uses a one thread per connection model so the only think to do is = to=20 recompile xmail and re-link with stack size increased to get more = 'threads'. Others models are a pool of threads, each handling many connections. Perhabs Davide could estimate if a change have to be done in code to = support this last model. This link could help understand this 'limit' :) http://blogs.msdn.com/oldnewthing/archive/2005/07/29/444912.aspx The final question is : Why so many connections ? Seems you will need to close more rapidly 'bad' connections with more efficient filters on xmail :) Francis -Message d'origine- De : [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] la part de Tracy Envoy=E9 : mardi 30 octobre 2007 12:13 =C0 : xmail@xmailserver.org Objet : [xmail] Re: XMail Win32 threads limit I have not noticed this specifically with xmail, but I have noticed = this=20 with other applications. I wrote a very simple test application once=20 (that did nothing but spawn threads which sat idle for 5 minutes, then=20 exited). The count was right around 1800 when the application became=20 unable to spawn additional threads - when some of the spawned threads=20 exited, the application was then able to spawn additional threads. Edinilson - ATINET wrote: Since a week we could note a massive (and abnormal) smtp connections = in our=20 XMail server (XMail 1.25 Win32 on Windows 2000 Server). After many adjusts in XMail threads to support this DDOS, we could = note an=20 interesting thing: Windows 2000 Server does not support more than = 1800=20 threads (counting all kind, pop3 threads, smtp threads, mailer = threads,=20 etc). After +-1800 threads, XMail.exe is still there but not answering = anymore. =20 Could others XMail Win32 users confirm this value (1800) ? =20 Regards =20 Edinilson - ATINET-Professional Web Hosting Tel Voz: (0xx11) 4412-0876 http://www.atinet.com.br=20 =20 - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED] =20 =20 - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED] - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] Re: XMail Win32 threads limit
On Tue, 30 Oct 2007, Edinilson - ATINET wrote: Since a week we could note a massive (and abnormal) smtp connections in our XMail server (XMail 1.25 Win32 on Windows 2000 Server). After many adjusts in XMail threads to support this DDOS, we could note an interesting thing: Windows 2000 Server does not support more than 1800 threads (counting all kind, pop3 threads, smtp threads, mailer threads, etc). After +-1800 threads, XMail.exe is still there but not answering anymore. Could others XMail Win32 users confirm this value (1800) ? It is *very* likely a VM space exhaustion due to the VM reservation that needs to be done for each thread stack. In Linux (and some Unixes in general) an `ulimit -s ` can solve the problem, that has been there since the introduction of the NPTL library. In Windows, XMail uses the default system stack size, even because there no completely portable (over the whole Windows family, from NT, up) way to reduce it. In general, 1000+ threads should be *more* than enough. I suggest you to use some good Maps inside the server.tab file, so that connections gets dropped immediately. I noticed the increase of spammer activity too, on xmailserver.org. About little more than one year ago, I had about 2-3000 rejections at Maps level, whereas the last week I saw than jumping to more than 40K. Unfortunately, spammer's Mom is always pregnant. - Davide - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] 1.25-pre20
I forgot about making the new pre-release: http://www.xmailserver.org/xmail-1.25-pre20.tar.gz http://www.xmailserver.org/xmail-1.25-pre20.win32bin.zip This has the new PSYNC timeout option, and I also updated OpenSSL binaries to the new version. - Davide - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] Re: 1.25-pre20
On Tue, 30 Oct 2007, Davide Libenzi wrote: I forgot about making the new pre-release: http://www.xmailserver.org/xmail-1.25-pre20.tar.gz http://www.xmailserver.org/xmail-1.25-pre20.win32bin.zip This has the new PSYNC timeout option, and I also updated OpenSSL binaries to the new version. The update of the OpenSSL binaries is meant only for Windows. Unix users they get them through apt-get, yum, what-ever-their-distro-uses way. - Davide - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] Re: XMail Win32 threads limit
Davide, how XMail handles the following situation: SERVER SIDE -EnableAuthSMTP-POP3 1 -Many CustMapsList configured MUA SIDE: -My server requires authentication *NOT* enabled The client try to send a message (smtp) AFTER a POP3 *BUT* your ip is listed in some blacklist configured in CustMapsList. Will XMail accept this smtp connection as authenticated? Regards Edinilson - ATINET-Professional Web Hosting Tel Voz: (0xx11) 4412-0876 http://www.atinet.com.br - Original Message - From: Davide Libenzi [EMAIL PROTECTED] To: xmail@xmailserver.org Sent: Tuesday, 30 de October de 2007 11:37 Subject: [xmail] Re: XMail Win32 threads limit On Tue, 30 Oct 2007, Edinilson - ATINET wrote: Since a week we could note a massive (and abnormal) smtp connections in our XMail server (XMail 1.25 Win32 on Windows 2000 Server). After many adjusts in XMail threads to support this DDOS, we could note an interesting thing: Windows 2000 Server does not support more than 1800 threads (counting all kind, pop3 threads, smtp threads, mailer threads, etc). After +-1800 threads, XMail.exe is still there but not answering anymore. Could others XMail Win32 users confirm this value (1800) ? It is *very* likely a VM space exhaustion due to the VM reservation that needs to be done for each thread stack. In Linux (and some Unixes in general) an `ulimit -s ` can solve the problem, that has been there since the introduction of the NPTL library. In Windows, XMail uses the default system stack size, even because there no completely portable (over the whole Windows family, from NT, up) way to reduce it. In general, 1000+ threads should be *more* than enough. I suggest you to use some good Maps inside the server.tab file, so that connections gets dropped immediately. I noticed the increase of spammer activity too, on xmailserver.org. About little more than one year ago, I had about 2-3000 rejections at Maps level, whereas the last week I saw than jumping to more than 40K. Unfortunately, spammer's Mom is always pregnant. - Davide - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED] - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
[xmail] Re: XMail Win32 threads limit
On Tue, 30 Oct 2007, Edinilson - ATINET wrote: Davide, how XMail handles the following situation: SERVER SIDE -EnableAuthSMTP-POP3 1 -Many CustMapsList configured MUA SIDE: -My server requires authentication *NOT* enabled The client try to send a message (smtp) AFTER a POP3 *BUT* your ip is listed in some blacklist configured in CustMapsList. Will XMail accept this smtp connection as authenticated? If the map code is zero, yes. - Davide - To unsubscribe from this list: send the line unsubscribe xmail in the body of a message to [EMAIL PROTECTED] For general help: send the line help in the body of a message to [EMAIL PROTECTED]
