Web Tier - Concurrency problems

edited June 2009 in Server
Hi
I need some help. I'm using RBServer 9.03 and I'm running the ASP Web
tier on a server. My problem is that if two users call the same report
but with different parameters at the same time, the result is the same
for both users although the result should be different according to the
parameters sent. If both users call their reports at differents times
it works ok.
Here is the way the WEB application call the report for each user.

user1:
http://myserver/rbWebPub/report.asp?content=pdf&volume=Reports&name=Report1&folder=v0d0&zoom=70&newsearch=T&asg0f0se=10&asg0f0sa=false
)

user2:
the same call but changing the parameter asg0f0se=10 for asg0f0se=569

running it at differents times it works ok but simoultaneously returns
the same report or result for both.

Any idea what I'm doing wrong.

Sorry about my english. Thanks

Comments

  • edited June 2009

    Have not heard of this before. If you examine the WebTier cache directory,
    can you determine whether two separate sessions are being created? Each
    session will have a unique SessionID (i.e. a GUID) that is a subdirectory
    under the main webtier cache directory.



    --
    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com

    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
  • edited June 2009
    Hi Nard
    Thanks for answering.
    In the cache directory there is only one directory created. If I wait
    until the first report appear and then I call the second one it works ok
    and two directories are created but if I make the call simoultaneously
    only one directory is created.
    On the other hand, it is correct the way I'm making the call directly
    from internet explorer as shown in the example sent?


    Nard Moseley (Digital Metaphors) escribió:
  • edited June 2009
    Hi Nard
    I'm Still having the same problem. The server is a Windows 2003 Server.
    I've tried to publish an ISAPI web tier in order to see if the problem
    disappears but I couldn't make it work. I've followed exactly all the
    steps mentioned in the developer's guide but the error http 404 in the
    web browser is a constant. How can I publish ISAPI webtier.dll in
    windows 2003 server? or How can I solve the ASP web tier concurrency
    problem? in the same server?


    Ignacio Alewaerts escribió:
  • edited June 2009

    This issue is being researched. I will post a follow up here.

    For ISAPI, check what version of IIS you are using and then refer to the
    applicable article..

    rbWiki..How to Deploy WebTier to IIS6

    http://www.digital-metaphors.com:/rbWiki/Server/Web_Tier/How_To...Deploy_to_IIS6

    rbWiki...How to Deploy WebTier to IIS7

    http://www.digital-metaphors.com/rbWiki/Server/Web_Tier/How_To...Deploy_to_IIS7



    --
    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com

    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
  • edited June 2009
    Yes, I've alerady done it. Now I have both, ASP and ISAPI running, but
    both with the same problem. Executing the same report with different
    parameters but simoultaneously the webtier gives me back the same report
    for both clients and with a short delay between both it works ok.
    I wonder how can I ensure independent sessions.
    Actually I'm calling the reprot in that way:

    http://myServer/rbWebPub/report.asp?content=pdf&volume=Reports&name=myReport&folder=v0d0&zoom=70&newsearch=T&asg0f0se="myParameter"&asg0f0sa=false

    where "myParameter" is what changes

    the same with the ISAPI webtier.dll instead of report.asp.

    Please I need a solution because I've no more time to solve it.
    thanks


    Nard Moseley (Digital Metaphors) escribió:
  • edited June 2009

    I could not duplicate your test results, however here is some info that I
    hope will help.

    I updated the WebTier ASP demo so that the ASP Com object creates/frees its
    own FWebTierModule rather than sharing a singleton instance.

    http://www.digital-metaphors.com/tips/rbWebTier_ASP.zip

    Here is a client application that I created for testing. It is a Delphi app
    that uses two TWebBrowser objects placed on a notebook. One button tests
    ISAPI and another button tests ASP. I tested agains the main demo server.

    http://www.digital-metaphors.com/tips/rbWebTierTestViaTWebBrowser.zip

    Once you download and test using the updated ASP demo, you can modify teh
    ProcessWebRequest method to generate a new session using the code below.
    (The WebTier should be generating a new session automatically, this code
    should not be necessary, but you can try it).

    uses
    rsWebSessionManager;

    function TReports.ProcessWebRequest(var QueryString, ContentString:
    OleVariant): OleVariant;
    var
    lParameters: TStringList;
    lWebRequest: TrsWebRequest;
    begin

    lParameters := TStringList.Create;

    try

    TrsWebRequestParser.ParseContent(QueryString, lParameters);
    TrsWebRequestParser.ParseContent(ContentString, lParameters);

    {use the incoming request parameters to create a TrsWebRequest}
    lWebRequest := FWebTierModule.WebTier.CreateWebRequest(lParameters, '');

    if not FWebTierModule.WebTier.SessionExists(lWebRequest) then
    gWebSessionManager.GetSessionForRequest(lWebRequest);

    Result := FWebTierModule.WebTier.ProcessWebRequest(lWebRequest);

    finally
    lParameters.Free;
    end;

    end;


    --
    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com

    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
  • edited June 2009
    Thanks Nard
    Yesterday I found an example of code posted that seems to force the
    generation of a Sesion ID. I supposed it should not be necessary
    because it should work as in the original ISAPI example, but for my
    surprise it worked!!. For any reason the web tier by it self did not
    generate independant session, but adding this extra lines it worked ok.
    Here is the lines added on the original webtier example. However I'll
    try your example.
    Thanks for answering so fast!

    uses
    WebReq,

    rsWebRequest,
    rsWebSessionManager;

    procedure TWebModule1.WebModule1WebActionItem1Action(Sender: TObject;
    Request: TWebRequest; Response: TWebResponse; var Handled: Boolean);
    var
    lWebRequest: TrsWebRequest;
    begin

    // create a TrsWebRequest object
    lWebRequest := rsWebTier1.CreateWebRequest(Request.QueryFields,
    Request.Content);

    // if the session does not exists, use the global WebSessionManager
    to create one
    if not rsWebTier1.SessionExists(lWebRequest) then
    gWebSessionManager.GetSessionForRequest(lWebRequest);

    // at this point we have a session id assigned
    // lWebRequest.SessionID;

    // process the web request
    Response.Content := rsWebTier1.ProcessWebRequest(lWebRequest);

    end;

    initialization
    if WebRequestHandler <> nil then
    WebRequestHandler.WebModuleClass := TWebModule1;


    Nard Moseley (Digital Metaphors) escribió:
  • edited June 2009

    Ok, great. Yes, the sample code you found is the same as the code I posted
    here, except that I adapted it for the ASP demo.



    --
    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com

    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
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