SSRS 2005 ReportViewer control requests are sequential not paralle

[David]

Hello,
We have a question regarding how ReportViewer control works (version
8.0.0.0, reporting services 2005).
We placed 3 report viewer controls in the same aspx page. All of them are
using the Async mode of the ReportViewer control.
The web server gets all requests concurrently, but we've seen that the Web
Server is sending the request to the Report Serivces server one by one
(sequentially) and not in parallel.
Why is that?
How can we make it be parallel?

The problematic request which is queued ( we checked that using fiddler on
the web server), is:
http://serverName/ReportServer?/DB_...rResponseAsXml=true&rs:AllowNewSessions=false


BTW If open the page in 3 different IE windows, the ReportViewers from
different Http Sessions do request the Reports in parallel.
But, if open it in the same IE7 window, in different tabs, it is sequential
requests.
Thanks

 

[Patrice]

If I remember IE7 can only run 2 http requests on the same hosts at the same
time.. This is likely the limitation you are seeing...

Try perhaps :
http://support.microsoft.com/kb/282402/en-us (How do I configure IE to
download more than two files at one time ?)

 

[David]

Hi Patrice,
We already aware to the limitation of IE7, and we changed it to be 8, after
that we’ve seen in the client machine using fiddler that the requests are
sent in parallel (which is good).
The problem is not between the client and the Web Server, but between the
Web server and the SSRS Web Service in the Reporting services server (we ran
Fiddler in the Web Server to catch the requests sent from the Web Server to
the Report Server).
Do you know if there is a limitation on the http connections between 2
servers? Or better yet, a limitation of the ReportViewer control which exists
more than once on the same page? or any other setting we can change to allow
such parallel requests
Thanks
David

 

[Patrice]

Do you know if there is a limitation on the http connections between 2
servers? Or better yet, a limitation of the ReportViewer control which
exists
more than once on the same page? or any other setting we can change to
allow
such parallel requests

Unfortunately, in most if not all cases I'm using SRSS as a back end and
stream PDF results to the end user. Hence I have no particular experience
with the viewer itself...

Another thing I can think of is that a web page (and likely a web service)
blocks on the session acquisation so that a single page or call can be made
for a given session. Could it be what you see ?

So perhaps something like
http://blog.structuretoobig.com/post/2006/03/16/Sessionless-ReportViewer-Control.aspx
could help (and the MSDN doc) to establish a sessionless connection to see
if it solves the problem...

Else someone else will have to help... Good luck.