Hi all,I'm seeing a weird problem that I'm running out of ideas on. I'm going to send this email to both the apache httpd users list and the tomcat users list (separate messages) but hoping for any ideas at all.
The issue is currently reproduced using Apache httpd 2.4.16, mod_jk 1.2.41 and tomcat 8.0.28.
I've created a very very simple JSP page that does nothing but print a small string, but I've tried changing the jsp page to print a very very large string (10000+ characters) and no difference.
If I POST to this JSP page, and something like mod_deflate is in place to force a chunked transfer the TCP packet capture looks like this:
No. Time Source Destination Protocol Length Info1850 4827.762721000 client server TCP 66 54131→2280 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 1851 4827.764976000 server client TCP 66 2280→54131 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 1852 4827.765053000 client server TCP 54 54131→2280 [ACK] Seq=1 Ack=1 Win=131328 Len=0 1853 4827.765315000 client server HTTP 791 POST /JSPtoPostTo HTTP/1.1 1854 4827.777981000 server client TCP 466 [TCP segment of a reassembled PDU] 1855 4827.982961000 client server TCP 54 54131→2280 [ACK] Seq=738 Ack=413 Win=130816 Len=0 1856 4832.770458000 server client HTTP 74 HTTP/1.1 200 OK (text/html) 1857 4832.770459000 server client TCP 60 2280→54131 [FIN, ACK] Seq=433 Ack=738 Win=65536 Len=0 1858 4832.770555000 client server TCP 54 54131→2280 [ACK] Seq=738 Ack=434 Win=130816 Len=0 1859 4832.770904000 client server TCP 54 54131→2280 [FIN, ACK] Seq=738 Ack=434 Win=130816 Len=0 1860 4832.774200000 server client TCP 60 2280→54131 [ACK] Seq=434 Ack=739 Win=65536 Len=0
Spdficially, note the 5 second delay between the first segment (No. 1854) and the second data segment (1856). The first segment contains the headers, the second segment contains the mod_deflate compressed contents.
Here's where it gets sort of interesting.I can only reproduce this with one client. We have a custom NPAPI plugin that this problem occurs on with all versions of firefox. I cannot reproduce it with any other client. I've used HttpRequester extension on firefox to construct an arbitrary POST. I've copied the raw HTTP request from the wireshark capture:
POST /Windchill/wtcore/jsp/wvs/mkannio.jsp?CSRF_NONCE=gXFm878tFEjetz6Y6DgPscd5WiSqzlzxuRYjnsx1Igq6hwio7ToBpeV8dgCk9nH95UEEn%2B9IQXXkhgqstENexI0dJ3HohATr8BkqwtAaTiW9hg6puEcum9UfUjqpigM%3D&GetNewASTFile=1&name=test123123123&type=0&path=OR:wt.viewmarkup.DerivedImage:52607&extension=.ast HTTP/1.1
Host: host:2280User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Cookie: JSESSIONID=F3B0524C87BD94396CCDE40FF837D2F8.tomcat1 Authorization: Basic d2NhZG1pbjp3Y2FkbWlu Connection: keep-alive Content-length: 0 Content-Type: text/plainand used ncat and curl to attempt to simulate the request and no luck reproducing it.
This does not occur with Apache httpd 2.2.31 and mod_jk 1.2.41. And so far, it only occurs when the server is on Windows.
I can't come up with any scenario where I can explain how the client could possibly be the factor.
I've enabled mod_jk's trace logging and according to mod_jk the ajp request was handled and processed in less than a second.
The timing really seems to imply that this is all somwhere in mod_deflate. But I've tried something similar by creating an html file and request it via a POST instead of a GET and the problem doesn't occur either.
Hoping for any ideas on where to go with this. Thanks, Andy --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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