Michael Ludwig wrote:
Torsten Foertsch schrieb:
On Wed 28 Jan 2009, André Warnier wrote:
I am looking for a debugging tool that would be able to repeatedly
issue HTTP requests to one or more URLs, and log any errors.
Preferably in Perl, and it must run on a Windows workstation.
Don't know about windows and its not perl but I use ab (comes with
httpd)
Apache's AB.exe works fine on Windows. But it is for stress testing.
Is that you want?
Or is it rather application monitoring you want to do?
It's neither one, or maybe a mixture of both.
I'll try to summarise the case :
We have a customer site (among many with the same setup) experiencing
some problem : users get "friendly" error messages in IE saying "this
page cannot be displayed". IE6 also sometimes adds a status bar message
saying "Server not found - DNS error" (but not always, it varies).
We cannot change IE6.
The setup is as follows :
Request:
IE6 -> Apache2.2 -> mod_jk1.2.28 -> Tomcat5.5 -> database app.
Response:
IE6 <- Apache2.2 <- mod_jk1.2.28 <- Tomcat5.5 <- database app.
The mod_jk error logs shows messages to the effect that the *response*
cannot be sent because the client has broken the connection.
Like :
[Mon Jan 19 15:02:52 2009] [6802:4416] [info]
ajp_process_callback::jk_ajp_common.c (1447): Writing to client aborted
or client network problems
[Mon Jan 19 15:02:52 2009] [6802:4416] [info]
ajp_service::jk_ajp_common.c (1846): (ajp13) request failed, because of
client write error without recovery in send loop attempt=0
(+ many of these)
Normally, that means the user clicked somewhere else, or on cancel
etc.., but we are pretty sure that it's not the case here (I've seen the
error myself at the customer site).
So we suspect a problem either with IE, or with the network at the
client side.
What I want to do, is to run some monitoring program on a client
station, instead of IE, which should simulate client accesses to the
same application, and tell me in detail if there is an error, and what
the error looks like. Unlike IE.
Then I can, maybe, cross-reference this with the errors seen in the
mod_jk log and find out if they are the same, or unrelated.
I hope for something that will log if it cannot access the site because
there is indeed a DNS error finding the server, or because it cannot
connect to the server, or because the server takes too long, or
whatever. Or that will tell me that it has no problem at all getting the
response from the server, which would be a clear sign that it's
something in IE6. Which I hope for, because we cannot find errors at
the app or app-server level so far.
Thanks.
And thanks also for the several responses and tips received so far.
I'm looking at them. It is not that there are no tools, it's more that
there are too many. Preferably, I am looking for something which I can
ask the customer themselves to install on a workstation and run, because
that would save me having to go on location again.
I do not have remote access to the client workstations, only to the server.
The workstation I'm thinking of already has perl installed.
I have tried "ab" already locally here, and it is relatively easy to
install on a Windows workstation (you install Apache for Win32).
One of my problems is that I have a bit of difficulty setting up a local
case of a network misbehaving from time to time, so I don't really know
how much debugging information "ab" provides when thrings go wrong. So
far, things go desperately right.. ;-)
