Larry Reisler wrote:
> Rainer --
> 
> I recently changed replaced the version of JBOSS Web we were using to 
> JBOSSWEB_2_0_0_GA_CP04.  It included several patches to the AJP code.  That 
> appears to have solved the problem.  The FIN packets from the back end come 
> back immediately now.  I'm guessing that the fix to JBPAPP-366 
> (http://jira.jboss.org/jira/browse/JBPAPP-366) fixed this too.
> 
> I still see the mod_jk architecture as problematic


JBPAPP-366 is http://svn.apache.org/viewvc?rev=589062&view=rev that was
a bug in the JAVA part not in mod_jk.

Cheers

Jean-Frederic

> -- it would be better if cleaning up the sockets would occur on a different 
> thread and without the critical section locked.
> 
> Larry
> 
> -----Original Message-----
> From: Larry Reisler [mailto:[EMAIL PROTECTED] 
> Sent: Monday, November 26, 2007 10:08 AM
> To: Rainer Jung; Tomcat Developers List
> Subject: RE: Delays in mod_jk
> 
> Rainer --
> 
> I am using out of the box JBOSS 4.21 -- no special connector, and no firewall 
> between the httpd tier and the other tier.
> 
> Indeed, I agree that the FIN packet from the back end is missing.  It seems 
> to come much later in the dump (exactly 4 minutes later).  I can't help but 
> think this is an issue on the JBOSS side, but I'm not sure where to go to try 
> to debug that.
> 
> I will send you the full capture file separately by private Mail.
> 
> Larry
> 
> 
> -----Original Message-----
> From: Rainer Jung [mailto:[EMAIL PROTECTED] 
> Sent: Sunday, November 25, 2007 4:35 PM
> To: Tomcat Developers List
> Subject: Re: Delays in mod_jk
> 
> Hi Larry,
> 
> I'm again investigating your problem report concerning 2 second pauses 
> during socket shutdown in JK maintenance. Sorry for the long pause, but 
> I want to see, if there is something we need to fix before 1.2.26 
> related to this case.
> 
> I couldn't reproduce the behaviour on Linux. Do you use a special 
> connector for AJP in JBoss, like Tomcats APR connector, or is it just 
> the plain Coyote connector? Is there a firewall in between httpd and 
> JBoss? If so, would it be possible to sniff again on both sides?
> 
> Larry Reisler wrote:
>> I got a trace using some of the settings you have below.  I'm not
>> quite sure how to get the whole thing to you, as it is fairly large,
>> and I don't wish to post it to the mailing list.
> 
> If you like, you can send it by private Mail.
> 
>> In any event the relevant lines from one example of an interaction I
>> am attaching below.  10.45.3.22 is the apache 2.2 server and
>> 10.45.3.21 and 10.45.3.24 are the tomcat servers.  The trace was
>> taken from the apache server.  There are numerous other examples of
>> this type of interaction.
>>
>> 02:49:04.329952 IP 10.45.3.22.34977 > 10.45.3.21.8009: F
>> 2991069804:2991069804(0) ack 1909717451 win 8244 <nop,nop,timestamp
>> 865633671 2700468480> 02:49:04.370343 IP 10.45.3.21.8009 >
>> 10.45.3.22.34977: . ack 1 win 1448 <nop,nop,timestamp 2700815038
>> 865633671> 02:49:06.329558 IP 10.45.3.22.34972 > 10.45.3.24.8009: F
>> 2991428814:2991428814(0) ack 330342931 win 4624 <nop,nop,timestamp
>> 865635671 4202573488> 02:49:06.369533 IP 10.45.3.24.8009 >
>> 10.45.3.22.34972: . ack 1 win 2269 <nop,nop,timestamp 4202873970
>> 865635671> 02:49:08.329843 IP 10.45.3.22.35008 > 10.45.3.24.8009: S
>> 3372523679:3372523679(0) win 5840 <mss 1460,sackOK,timestamp
>> 865637671 0,nop,wscale 2> 02:49:08.329961 IP 10.45.3.24.8009 >
>> 10.45.3.22.35008: S 707449532:707449532(0) ack 3372523680 win 5792
>> <mss 1460,sackOK,timestamp 4202875930 865637671,nop,wscale 2> 
>> 02:49:08.329972 IP 10.45.3.22.35008 > 10.45.3.24.8009: . ack 1 win
>> 1460 <nop,nop,timestamp 865637671 4202875930> 02:49:08.330001 IP
>> 10.45.3.22.35008 > 10.45.3.24.8009: P 1:821(820) ack 1 win 1460
>> <nop,nop,timestamp 865637671 4202875930> 02:49:08.330023 IP
>> 10.45.3.22.35008 > 10.45.3.24.8009: P 821:921(100) ack 1 win 1460
>> <nop,nop,timestamp 865637671 4202875930>
>>
>> My analysis of this is as follows: 1) A request comes in to the
>> apache server, which has two timed out socket connections to the
>> tomcat servers on ports 34977 and 34972.  At 02:49:04.329952 it sends
>> a FIN packet to the tomcat server and receives a response at
>> 02:49:04.370343.  It then waits two seconds from the time it sent the
>> FIN packet. 2) At 02:49:06.329558 it sends a FIN packet to the other
>> tomcat server and receives a response at 02:49:06.369533.  It then
>> waits two seconds from the time it sent the FIN packet, and then
>> creates a new socket (35008) on which it successfully sends the
>> transaction.
> 
> The tcpdump excerpt seems to be incomplete. After the FIN and the 
> accompanying ACK, the final FIN/ACK from the backend is missing. Does it 
> occur later in the dump? If not, there should be a RST or the connection 
> should still be in CLOSE_WAIT on the JBoss machine.
> 
> Regards,
> 
> Rainer
> 


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