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Report From: Delphi-BCB/Bold/Persistence    [ Add a report in this area ]  
Report #:  4089   Status: Closed
HTTP Mapper fails when multiple clients connect concurrently
Project:  Delphi Build #:  March patch
Version:    7.0 Submitted By:   rafael zz
Report Type:  Basic functionality failure Date Reported:  4/10/2003 3:18:18 PM
Severity:    Serious / Highly visible problem Last Updated: 3/20/2012 2:24:39 AM
Platform:    All platforms Internal Tracking #:   194222
Resolution: Retest (Resolution Comments) Resolved in Build: : 7.0.95.395
Duplicate of:  None
Voting and Rating
Overall Rating: (4 Total Ratings)
4.25 out of 5
Total Votes: 4
Description
When multiple client apps connect via the HTTP Mapper, there  are deadlocks on the server.
Steps to Reproduce:
We confirm that there is similar problem with HTTPPMapper sample app.
Although, we don't get exactly the same error message as we do with
SynapsePersistenceHandle.

1. Using the 'out of box' default HTTPPMapper model configuration we get different messages, mostly related
to updating bold x-files.

2. If we tweak the HTTPPMapper configuration to drop the x-files and timestamps we get a deadlock somewhere on
the server.

  (Steps to drop the x-files and timestamps:
      1-open Bold model,
      2-select root object in the tree,
      3-uncheck "use x files" and "use timestamp",
      4-regenerate database, regenerate code)


Steps to reproduce the problem either with or without the x-files/timestamps:

1. Open HTTPPMapper\HTTPClient project

2. Add a button with following click handler

procedure Tallform.b_InsertBatchClick(Sender: TObject);
const
  iMax = 50;
var
  i    : integer;
begin
  for i := 0 to iMax - 1 do begin
    blhAllPerson.List.AddNew;
    btnUpdateDB.Click;
  end;
end;

3. Run 2 copies of HTTPClient, open systems in both copies and then press this "new" button in two apps simultaneously
Workarounds
None
Attachment
None
Comments

Stefan Westner at 9/24/2003 7:16:39 AM -
This problem does not only occur in the HTTPMapper but in the same manner if to seperate fat-clients access the bold-database at the same time doing heavily database work.

Server Response from: ETNACODE01

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