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Mike Irvine Guest
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Posted: Fri Jun 23, 2006 5:08 pm Post subject: Random Timeouts due to webservice failure to respond |
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I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike |
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Deepak Shenoy Guest
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Posted: Sat Jun 24, 2006 12:16 am Post subject: Re: Random Timeouts due to webservice failure to respond |
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Mike Irvine wrote:
| Quote: | Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
|
Do you think this might be the problem (if the servers in D7)
http://shenoyatwork.blogspot.com/2004/06/soap-insanity-expecting-textxml
..html
Actually what you see is the GET for the WSDL and the POST for the
actual SOAP call. (Responses aren't recorded in the IIS log) So if you
see a GET but no corresponding POST that means the problem's at the
client, not the server.
Try changing the call to not download or use the WSDL each time, that
might also give you a clue.
--
Deepak Shenoy [TeamB]
http://shenoyatwork.blogspot.com |
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Mike Irvine Guest
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Posted: Mon Jun 26, 2006 2:09 pm Post subject: Re: Random Timeouts due to webservice failure to respond |
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Thanks, for the info this may not solve the issue but it will definately help us in tracking down the problem (I hope).
I wasn't sure if the IIS logs directly linked up with the webservice actions but it seemed likely. Your explanation ties up more with our network traces which show an initial connection (must be the WSDL retrieval) but then nothing.
After reading your blog, I checked my webservice and it's dpr is actually correct (which is surprising as I didn't know about this bug and as far as I know didn't change the default dpr settings creating the webservice).
I am going to change the call so that it doesn't retrieve the WSDL each time. So that will leave us with a chance to track only the POST to the webservice. Hopefully this will help us track down the problem (be it Client or Network).
"Deepak Shenoy" <noname (AT) noname (DOT) com> wrote:
| Quote: | Mike Irvine wrote:
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
Do you think this might be the problem (if the servers in D7)
http://shenoyatwork.blogspot.com/2004/06/soap-insanity-expecting-textxml
.html
Actually what you see is the GET for the WSDL and the POST for the
actual SOAP call. (Responses aren't recorded in the IIS log) So if you
see a GET but no corresponding POST that means the problem's at the
client, not the server.
Try changing the call to not download or use the WSDL each time, that
might also give you a clue.
--
Deepak Shenoy [TeamB]
http://shenoyatwork.blogspot.com |
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Mike Irvine Guest
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Posted: Fri Jul 14, 2006 2:22 pm Post subject: Re: Random Timeouts due to webservice failure to respond |
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Seems my response has disappeared (must have posted it from google).
Anyway - thanks for the help and information (I've now changed my client to avoid the double Get Post overhead).
I also checked and the webservice doesn't have the problem that your blog refers to as the units are used in the correct order.
We think we have located the problem now (or at least we think we have). What we've found has nothing to do with delphi but more the hardware/architecture, I'll just include it here in case of anyone experiencing the same issues.
From our server traces , it looks like that occasionally our client was not receiving all the data packets sent by our
server. It seems to be due to some bug in Microsoft regarding MTU sizes causing packet fragmentisation when the packets get too large (which seems to co-incide with user timeouts). We are reducing the MTU to a level to avoid fragmentistation and are hoping that this will fix our issue.
I realise this is all a bit server-techy (it was only our network gurus who spotted this through monitoring and got microsoft involved) but this may help any others if they experience irregular random timeouts from webservices on an internal network.
"Deepak Shenoy" <noname (AT) noname (DOT) com> wrote:
| Quote: | Mike Irvine wrote:
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
Do you think this might be the problem (if the servers in D7)
http://shenoyatwork.blogspot.com/2004/06/soap-insanity-expecting-textxml
.html
Actually what you see is the GET for the WSDL and the POST for the
actual SOAP call. (Responses aren't recorded in the IIS log) So if you
see a GET but no corresponding POST that means the problem's at the
client, not the server.
Try changing the call to not download or use the WSDL each time, that
might also give you a clue.
--
Deepak Shenoy [TeamB]
http://shenoyatwork.blogspot.com |
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..Rather helpful informat Guest
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Posted: Wed Mar 07, 2007 5:12 am Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
..Rather helpful information you have here. Grazie! http://www.trenitalia.275mb.com
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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Luogo molto buon:) Buona Guest
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Posted: Sun Mar 11, 2007 3:07 pm Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
Luogo molto buon:) Buona fortuna! http://www.paradistc.org/tempo
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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E evidente che il luogo e Guest
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Posted: Wed Mar 14, 2007 1:49 am Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
E evidente che il luogo e stato fatto dalla persona che realmente conosce il mestiere! http://www.paradistc.org/napoli
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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Jean-Marie Babet Guest
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Posted: Wed Mar 14, 2007 6:45 am Post subject: Re: Random Timeouts due to webservice failure to respond |
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Hello,
| Quote: | In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
|
The fact that there's always a 'GET' followed by a 'POST' leads me to
believe that you're using the RIO component with the WSDLLocation property
instead of the 'URL'. The first release of Delphi SOAP (v6.0) required that
one uses the WSDLLocation with non-Delphi service because we needed to
lookup the SOAPAction. Subsequent versions of the importer were updated to
generate and register the SOAPAction during the importer process. So unless
you're using D6 I recommend that you use the URL property of the THTTPRIO:
for one, it's faster (as we avoid the 'GET').
I don't know if that will help with the timeout but I run several clients
(unit tests) every 4 hours against several test webservices (delphi
webservices and others - mainly .NET and Axis) and I have not noticed the
timeouts.. but I don't use the WSDLLocation property.
If the above does not help, please let me know and we'll try to find out a
little more.
Cheers,
Bruneau. |
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um... buoni, realmente bu Guest
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Posted: Fri Mar 16, 2007 8:13 am Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
um... buoni, realmente buoni luogo e molto utile;) http://www.sanzkdni59.org/campioni
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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Lo trovo piuttosto impres Guest
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Posted: Sun Mar 18, 2007 3:33 am Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
Lo trovo piuttosto impressionante. Lavoro grande fatto..) http://www.sanzkdni59.org/zidane
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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WOW!! I like it! http://w Guest
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Posted: Mon Mar 19, 2007 6:42 pm Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
WOW!! I like it! http://www.paradistc.org/winnie-the-pooh
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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mmm.. nice design, I must Guest
|
Posted: Wed Mar 21, 2007 1:13 am Post subject: RE: Random Timeouts due to webservice failure to respond |
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| Quote: |
I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
|
mmm.. nice design, I must say.. http://www.sanzkdni59.org/pompini
BizTalk Utilities - Frustration free BizTalk Adapters
http://www.topxml.com/biztalkutilities |
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Gabriel Izar Guest
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Posted: Wed Mar 21, 2007 1:40 am Post subject: Re: Random Timeouts due to webservice failure to respond |
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"Jean-Marie Babet" <bbabet (AT) borland (DOT) com> escreveu na mensagem
news:45f7539d$1 (AT) newsgroups (DOT) borland.com...
| Quote: | Hello,
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
The fact that there's always a 'GET' followed by a 'POST' leads me to
believe that you're using the RIO component with the WSDLLocation property
instead of the 'URL'. The first release of Delphi SOAP (v6.0) required
that
one uses the WSDLLocation with non-Delphi service because we needed to
lookup the SOAPAction. Subsequent versions of the importer were updated to
generate and register the SOAPAction during the importer process. So
unless
you're using D6 I recommend that you use the URL property of the THTTPRIO:
for one, it's faster (as we avoid the 'GET').
I don't know if that will help with the timeout but I run several clients
(unit tests) every 4 hours against several test webservices (delphi
webservices and others - mainly .NET and Axis) and I have not noticed the
timeouts.. but I don't use the WSDLLocation property.
If the above does not help, please let me know and we'll try to find out a
little more.
Cheers,
Bruneau.
|
I have this same problem and, of course I'm also using the WSDLLocation
property instead of URL Property. I want to test performance using URL, but
how can I do that ? Wich is the right URL for my soap web service ? |
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Jean-Marie Babet Guest
|
Posted: Wed Mar 21, 2007 8:13 am Post subject: Re: Random Timeouts due to webservice failure to respond |
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|
Hello,
| Quote: | I have this same problem and, of course I'm also using the WSDLLocation
property instead of URL Property. I want to test performance using URL,
but
how can I do that ? Wich is the right URL for my soap web service ?
|
The URL is listed in the factory method created by the importer for each
interface/porttype found in the WSDL. For example, if you import eBay's
WSDL, you'll find the following:
function GeteBayAPIInterface(UseWSDL: Boolean; Addr: string; HTTPRIO:
THTTPRIO): eBayAPIInterface;
const
defWSDL = 'http://developer.ebay.com/webservices/latest/eBaySvc.wsdl';
defURL = 'https://api.ebay.com/wsapi';
defSvc = 'eBayAPIInterfaceService';
defPrt = 'eBayAPI';
The 'defURL' variable points to the URL. Search for 'defURL' in the file
generated by the importer.
Cheers,
Bruneau. |
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9 su 10! Ottenerlo! Siete Guest
|
Posted: Sat Mar 31, 2007 8:13 am Post subject: RE: Random Timeouts due to webservice failure to respond |
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I am experiencing an intermittent problem with a delphi webservice.
Basically we have a client application hitting the webservice multiple
times a day - and by in large no problems. However very occasionally
we see a Timeout - (basically we are waiting for a response from our
webservice but we get nothing back). The Timeout is self-generated
as I have written a background thread to monitor the status of the
request to the webservice - as without this the Client simply hangs
indefintately as it never receives a response.
We have implemented logging on our webservice so that everytime it
receives a hit it writes info to a logging file. And what we have
noticed is that when we see a timeout - we have no hit in our
webservice logs. However if we look at the IIS logfile we see that we
received the request from the Client and the webservice should be
called - but nothing happens.
In Normal operation the IIS logs shows a GET entry (the client's
request I presume) followed by a POST (I assume the returning data)
from our webservice back to the user. In the case of the Timeout we
see a GET but no following POST entry.
I am thinking that our webservice IS getting called but it is either
ignoring or not handling the request as we are not seeing an entry in
our webservices logfile.
There is nothing special about the request that timesout. If the users
resubmits the exact same request after the timeout - it is handled
correctly.
It is not a concurrency issue as sometimes this timeout occurs when a
single client is accessing the webservice.
We are using IIS 6 on a windows 2K box, webservice is a Soap ISAPI DLL
written in Delphi 7.
We've been struggling with this one as it isn't perfectly recreatable
(we wrote a test module to hit the webservice and it ran for an entire
day without issues!)
Does any one have any idea what might be causing the problem? Or any
ideas what next steps to take in tracking down the problem? We have
network guys and server techs also monitoring and investigating this in
case it turns out to be a network or server issue but again so far no
joy.
Any advice/help gratefully appreciated
Mike
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