异步插座&活动连接 [英] Async socket & active connections
问题描述
为了创建一个完整的网络浏览器我发现自己
在Socket类中编写一个包装器尝试使它完全异步，支持超时和一些调度机制。
我使用非阻塞方法，使用调用''poll''
支持异步机制 - 而不是''开始''和''结束''
函数。我已经发现连接没有设置
" isconnected"变量正确（抛出SocketException：非
阻塞有这种效果......） - 但似乎不是问题
因为轮询，读写工作正常。
为了测量爬虫的性能，我开始perfmon.msc
并添加了活动连接。来自对象TCP的项目。在
之后我发现这个性能计数器的数量达到了超过
300K连接（！），足以开始担心...
我的抓取工具旨在同时支持大约200个连接。
" netstat -an"并不支持这一发现，但确实显示了数百个
连接，这些连接位于CLOSE_WAIT，FIN_WAIT_2和FIN_WAIT中。或者另一个
关闭状态。
主机完成后，我尝试断开TCP / IP连接。
我'尝试'shutdown（both）'，（async）" disconnect"
和'close（0）"的组合。 - 没有任何组合似乎具有所需的
效果。关闭应用程序后，将删除所有连接（包括
CLOSE_WAIT连接）。 FIN_WAIT_2连接
永远逗留...
也许有人知道这个问题的解决方案吗？
问候，
Stefan de Bruijn。
3月25日21:48， " atlaste" < atla ... @ gmail.comwrote：
试图创造一个全面的webcrawler我找到了自己
在Socket类周围编写一个包装器，试图使它完全异步，支持超时和一些调度机制。
我使用非阻塞方法，使用调用''poll''
支持异步机制 - 而不是''begin''和''end' '
功能。我已经发现连接没有设置
" isconnected"变量正确（抛出SocketException：非
阻塞有这种效果......） - 但似乎不是问题
因为轮询，读写工作正常。
为了测量爬虫的性能，我开始perfmon.msc
并添加了活动连接。来自对象TCP的项目。在
之后我发现这个性能计数器的数量达到了超过
300K连接（！），足以开始担心...
我的抓取工具旨在同时支持大约200个连接。
" netstat -an"并不支持这一发现，但确实显示了数百个
连接，这些连接位于CLOSE_WAIT，FIN_WAIT_2和FIN_WAIT中。或者另一个
关闭状态。
主机完成后，我尝试断开TCP / IP连接。
我'尝试'shutdown（both）'，（async）" disconnect"
和'close（0）"的组合。 - 没有任何组合似乎具有所需的
效果。关闭应用程序后，将删除所有连接（包括
CLOSE_WAIT连接）。 FIN_WAIT_2连接
永远逗留...
也许有人知道这个问题的解决方案吗？
问候，
Stefan de Bruijn。
只是一个猜测，你可以在keepalive设置为0的情况下尝试吗？
类似于s是Socket的地方：
s.SetSocketOption（System.Net.Sockets.SocketOptionL evel.IP，
System.Net.Sockets.SocketOptionName.KeepAlive，0）;
感谢您的反应。
这是我对TCP / IP的理解keepalive有不同的含义
（参见 http://msdn.microsoft.com/library/de...et_options.asp
和 http://msdn2.microsoft.com/en-us/lib...ptionname。 aspx
）比你的建议。将其设置为true应该在2小时后关闭
连接或类似的事情。 （因为两个小时
听起来像是一辈子给我，我可以看到名字keepalive
来源:-)
所以虽然把它设置为真的确实是个好主意 -
并没有真正解决我的问题我很害怕。
也许有人有另一个建议？
干杯，
Stefan de Bruijn。
3月26日，11日：上午44点，DeveloperX < nntp ... @ operamail.comwrote：
3月25日21:48，atlaste < atla ... @ gmail.comwrote：
In尝试创建一个完整的webcrawler我发现自己
在Socket类周围编写一个包装器，试图使它完全异步，支持超时和支持超时一些调度机制。
我使用非阻塞方法，使用调用''poll'来支持异步机制 - 而不是''开始''和''结束''
函数。我已经发现连接没有设置
" isconnected"变量正确（抛出SocketException：非
阻塞有这种效果......） - 但似乎不是问题
因为轮询，读写工作得很好。
为了衡量抓取工具的性能，我开始perfmon.msc
并添加了有效连接"来自对象TCP的项目。在
之后我发现这个性能计数器的数量达到了超过
300K连接（！），足以开始担心...
我的抓取工具旨在同时支持大约200个连接。
" netstat -an"并不支持这一发现，但确实显示了数百个
连接，这些连接位于CLOSE_WAIT，FIN_WAIT_2和FIN_WAIT中。或另一个
关闭状态。
主机完成后，我尝试断开TCP / IP连接。
我尝试过组合shutdown（both），（async）" disconnect"
和close（0）" - 没有任何组合似乎具有所需的
效果。关闭应用程序后，将删除所有连接（包括
CLOSE_WAIT连接）。 FIN_WAIT_2连接
永远逗留...
也许有人知道这个问题的解决方案？
Greetings，
Stefan de Bruijn。
只是一个猜测，你可以尝试将keepalive设置为0吗？
类似于s是Socket的地方：
s.SetSocketOption（System.Net.Sockets.SocketOptionL evel.IP，
System.Net.Sockets.SocketOptionName.KeepAlive，0）;
3月26日12:43，atlaste < atla ... @ gmail.comwrote：
感谢您的反应。
这是我对TCP的理解/ IP keepalive有不同的含义
（参见http://msdn.microsoft.com/library/default.asp?url = / library / en-us / wins ...
andhttp：//msdn2.microsoft.com/en-us/library/system.net.sockets.socketopt ...
）比你的建议。将其设置为true应该在2小时后关闭
连接或类似的事情。 （因为两个小时
听起来像是一辈子给我，我可以看到名字keepalive
来源:-)
所以虽然把它设置为真的确实是个好主意 -
并没有真正解决我的问题我很害怕。
也许有人有另一个建议？
干杯，
Stefan de Bruijn。
开3月26日上午11:44，DeveloperX < nntp ... @ operamail.comwrote：
3月25日21:48，atlaste < atla ... @ gmail.comwrote：
为了创建一个完整的网络浏览器我发现自己已经找到了自己
写一个包装器在Socket类周围尝试使它完全异步，支持超时和一些调度机制。
我使用非阻塞方法，使用调用''poll''
支持异步机制 - 而不是''开始''和''结束''
函数。我已经发现连接没有设置
" isconnected"变量正确（抛出SocketException：非
阻塞有这种效果......） - 但似乎不是问题
因为轮询，读写工作得很好。
为了测量爬虫的性能，我开始使用perfmon.msc
并添加了活动连接来自对象TCP的项目。在
之后我发现这个性能计数器的数量达到了超过
300K连接（！），足以开始担心...
我的抓取工具旨在同时支持大约200个连接。
" netstat -an"并不支持这一发现，但确实显示了数百个
连接，这些连接位于CLOSE_WAIT，FIN_WAIT_2和FIN_WAIT中。或另一个
关闭状态。
主机完成后，我尝试断开TCP / IP连接。 />
我尝试过组合shutdown（both），（async）" disconnect"
和close（0） - 没有任何组合似乎具有所需的
效果。关闭应用程序后，将删除所有连接（包括
CLOSE_WAIT连接）。 FIN_WAIT_2连接
永远逗留...
也许某人知道这个问题的解决方案吗？
Greetings，
Stefan de Bruijn。
只是一个猜测，你可以尝试将keepalive设置为0吗？
类似于s是Socket的地方：
s。 SetSocketOption（System.Net.Sockets.SocketOptionL evel.IP，
System.Net.Sockets.SocketOptionName.KeepAlive，0）; - 隐藏引用的文本 -
- 显示引用的文字 -
啊，是的，我知道，如何更改灵儿选项？
基本上这个建议是因为我读到的一些内容
Apache更改关闭连接的方法也变成了Linger_Close
并且它给人们带来了很多FIN_WAIT_2问题。
再次，只是一个想法:)
Hi,
In an attempt to create a full-blown webcrawler I''ve found myself
writing a wrapper around the Socket class in an attempt to make it
completely async, supporting timeouts and some scheduling mechanisms.
I use a non-blocking approach for this, using the call to ''poll'' to
support the async mechanism - rather than the ''begin'' and ''end''
functions. I already found that connecting doesn''t set the
"isconnected" variable correctly (SocketException is thrown: non-
blocking has this effect...) - but doesn''t appear to be a problem
because poll, read and write work fine.
For measuring the performance of the crawler, I started "perfmon.msc"
and added the "active connections" item from object "TCP". After a
while I found the number of this performance counter to reach over
300K connections (!), enough to start worrying...
My crawler is designed to support around 200 connections simultaneous.
"netstat -an" doesn''t support this finding, but does show hundreds of
connections that are in either "CLOSE_WAIT", "FIN_WAIT_2" or another
closing state.
After a host has completed, I try to disconnect the TCP/IP connection.
I''ve attempted combinations of "shutdown(both)", (async) "disconnect"
and "close(0)" - where no combination appears to have the desired
effect. When the application is shut down, all connections (including
the CLOSE_WAIT connections) are removed. The FIN_WAIT_2 connections
linger forever...
Perhaps someone knows a solution to this problem?
Greetings,
Stefan de Bruijn.
On 25 Mar, 21:48, "atlaste" <atla...@gmail.comwrote:Hi,
In an attempt to create a full-blown webcrawler I''ve found myself
writing a wrapper around the Socket class in an attempt to make it
completely async, supporting timeouts and some scheduling mechanisms.
I use a non-blocking approach for this, using the call to ''poll'' to
support the async mechanism - rather than the ''begin'' and ''end''
functions. I already found that connecting doesn''t set the
"isconnected" variable correctly (SocketException is thrown: non-
blocking has this effect...) - but doesn''t appear to be a problem
because poll, read and write work fine.
For measuring the performance of the crawler, I started "perfmon.msc"
and added the "active connections" item from object "TCP". After a
while I found the number of this performance counter to reach over
300K connections (!), enough to start worrying...
My crawler is designed to support around 200 connections simultaneous.
"netstat -an" doesn''t support this finding, but does show hundreds of
connections that are in either "CLOSE_WAIT", "FIN_WAIT_2" or another
closing state.
After a host has completed, I try to disconnect the TCP/IP connection.
I''ve attempted combinations of "shutdown(both)", (async) "disconnect"
and "close(0)" - where no combination appears to have the desired
effect. When the application is shut down, all connections (including
the CLOSE_WAIT connections) are removed. The FIN_WAIT_2 connections
linger forever...
Perhaps someone knows a solution to this problem?
Greetings,
Stefan de Bruijn.Just a guess, can you try it with keepalive set to 0?
Something like where s is a Socket:
s.SetSocketOption(System.Net.Sockets.SocketOptionL evel.IP,
System.Net.Sockets.SocketOptionName.KeepAlive, 0);
Thanks for your reaction.
It is my understanding from TCP/IP keepalive have a different meaning
(see http://msdn.microsoft.com/library/de...et_options.asp
and http://msdn2.microsoft.com/en-us/lib...ptionname.aspx
) than what you would suggest. Setting it to "true" should close the
connection after 2 hours or something like that. (Since two hours
sounds like "a lifetime" to me, I can see where the name "keepalive"
originated :-)
So while it actually sound like a good idea to set it to true -
doesn''t really solve my problem I''m afraid.
Perhaps someone has another suggestion?
Cheers,
Stefan de Bruijn.
On Mar 26, 11:44 am, "DeveloperX" <nntp...@operamail.comwrote:On 25 Mar, 21:48, "atlaste" <atla...@gmail.comwrote:
Hi,
In an attempt to create a full-blown webcrawler I''ve found myself
writing a wrapper around the Socket class in an attempt to make it
completely async, supporting timeouts and some scheduling mechanisms.
I use a non-blocking approach for this, using the call to ''poll'' to
support the async mechanism - rather than the ''begin'' and ''end''
functions. I already found that connecting doesn''t set the
"isconnected" variable correctly (SocketException is thrown: non-
blocking has this effect...) - but doesn''t appear to be a problem
because poll, read and write work fine.
For measuring the performance of the crawler, I started "perfmon.msc"
and added the "active connections" item from object "TCP". After a
while I found the number of this performance counter to reach over
300K connections (!), enough to start worrying...
My crawler is designed to support around 200 connections simultaneous.
"netstat -an" doesn''t support this finding, but does show hundreds of
connections that are in either "CLOSE_WAIT", "FIN_WAIT_2" or another
closing state.
After a host has completed, I try to disconnect the TCP/IP connection.
I''ve attempted combinations of "shutdown(both)", (async) "disconnect"
and "close(0)" - where no combination appears to have the desired
effect. When the application is shut down, all connections (including
the CLOSE_WAIT connections) are removed. The FIN_WAIT_2 connections
linger forever...
Perhaps someone knows a solution to this problem?
Greetings,
Stefan de Bruijn.
Just a guess, can you try it with keepalive set to 0?
Something like where s is a Socket:
s.SetSocketOption(System.Net.Sockets.SocketOptionL evel.IP,
System.Net.Sockets.SocketOptionName.KeepAlive, 0);
On 26 Mar, 12:43, "atlaste" <atla...@gmail.comwrote:Thanks for your reaction.
It is my understanding from TCP/IP keepalive have a different meaning
(seehttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/wins...
andhttp://msdn2.microsoft.com/en-us/library/system.net.sockets.socketopt...
) than what you would suggest. Setting it to "true" should close the
connection after 2 hours or something like that. (Since two hours
sounds like "a lifetime" to me, I can see where the name "keepalive"
originated :-)
So while it actually sound like a good idea to set it to true -
doesn''t really solve my problem I''m afraid.
Perhaps someone has another suggestion?
Cheers,
Stefan de Bruijn.
On Mar 26, 11:44 am, "DeveloperX" <nntp...@operamail.comwrote:
On 25 Mar, 21:48, "atlaste" <atla...@gmail.comwrote:
Hi,
In an attempt to create a full-blown webcrawler I''ve found myself
writing a wrapper around the Socket class in an attempt to make it
completely async, supporting timeouts and some scheduling mechanisms.
I use a non-blocking approach for this, using the call to ''poll'' to
support the async mechanism - rather than the ''begin'' and ''end''
functions. I already found that connecting doesn''t set the
"isconnected" variable correctly (SocketException is thrown: non-
blocking has this effect...) - but doesn''t appear to be a problem
because poll, read and write work fine.
For measuring the performance of the crawler, I started "perfmon.msc"
and added the "active connections" item from object "TCP". After a
while I found the number of this performance counter to reach over
300K connections (!), enough to start worrying...
My crawler is designed to support around 200 connections simultaneous.
"netstat -an" doesn''t support this finding, but does show hundreds of
connections that are in either "CLOSE_WAIT", "FIN_WAIT_2" or another
closing state.
After a host has completed, I try to disconnect the TCP/IP connection.
I''ve attempted combinations of "shutdown(both)", (async) "disconnect"
and "close(0)" - where no combination appears to have the desired
effect. When the application is shut down, all connections (including
the CLOSE_WAIT connections) are removed. The FIN_WAIT_2 connections
linger forever...
Perhaps someone knows a solution to this problem?
Greetings,
Stefan de Bruijn.
Just a guess, can you try it with keepalive set to 0?
Something like where s is a Socket:
s.SetSocketOption(System.Net.Sockets.SocketOptionL evel.IP,
System.Net.Sockets.SocketOptionName.KeepAlive, 0);- Hide quoted text -
- Show quoted text -Ah yes I see, how about changing the Linger option?
Basically the suggestion comes because of something I read about
Apache changing a method to close connections too become Linger_Close
and it caused lots of FIN_WAIT_2 issues for people.
Again, just an idea :)
这篇关于异步插座&活动连接的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
