"with large datasets, we see a lag in the transport time over our web service.
For example, we have a data set that returns 5000 rows of 125 columns of
data...our T-SQL stored proc generates the data set in 6 seconds or less but
then it still takes anywhere from 45s to 1.5m to transport that dataset to the
client side...and that's over a fast connection..."
This is exactly one of the reasons to use AMF on the wire. Serialization of
5000 records with WebORB would take only a sub-second of time.
Mark
--- In flexcoders@yahoogroups.com, Adrian Williams <adri...@...> wrote:
>
> Hi there...
>
> We have a rather large RIA using C#.Net as the backend...and we have
> a large number of arrayCollections and dataGrids/advancedDataGrids....
>
> We don't massage any of the data that we are passing with our web
> services...we literally pass as as it's created...i.e. as an Array or as
> a Object...
>
> For example, we may have an AdvancedDataGridthat is asking for data
> from our web service...in our .net code we'd simply have something like:
>
> public List<MainClass> BuildTheArray(string Group, string Admin)
> {
> List<MainClass> configs = new List<MainClass>();
>
> SqlParameters[] sqlParams = new SqlParameters[2];
>
> sqlParams[0] = new SqlParameter("@Group", Group);
> sqlParams[1] = new SqlParameter("@Admin", Admin);
>
> try
> {
> using (SqlDataReader dr =
> (SqlDataReader)DB.Instance().ExecuteReader("main_stored_procedure",
> sqlParams))
> {
> while (dr != null && dr.Read())
> {
> configs.Add(new MainClass(
> Convert.ToString(dr["Name"]),
> Convert.ToString(dr["Email"]),
> etc...
> }
> }
> }
> return configs;
> }
>
> Then in our Flex webservice def, we are defining the result as
> "Object" (which I've seen a number of folks sugges E4X, but I've not
> delved into the pros/cons of this).
>
> <mx:operation name="GetConfigs" resultFormat="object"
> result="getConfigsResult(event)" />
>
> Now, since it's an object, in our web service result handler, you
> can cast it a number of ways, but for the list as created above on the
> .net side and since we are putting this data in an AdvancedDataGrid, we
> simply say:
>
> private function getConfigsResult(event:ResultEvent):void
> {
> configs = event.result as ArrayCollection;
> ourDataGrid.dataProvider = configs;
> }
>
> Generally speaking, out of the 100+ web service calls we have, any
> that return any kind of dataset we cast directly as an Array,
> ArrayCollection or Object.
>
> Now that said, we have seen something that is aggravating...with
> large datasets, we see a lag in the transport time over our web
> service. For example, we have a data set that returns 5000 rows of 125
> columns of data...our T-SQL stored proc generates the data set in 6
> seconds or less but then it still takes anywhere from 45s to 1.5m to
> transport that dataset to the client side...and that's over a fast
> connection...then, once it's in the client side, depending on how much
> custom rendering we are doing, it takes up to 10-15 sec's to render the
> data. So we have a bottleneck in our web service that causes a lengthy
> delay on large data sets....we are still researching on why this is
> happening and the fix but just wanted to let you know as a heads up.
>
> -HTH
> -adrian
>
>
>
> Sam Lai wrote:
> >
> >
> > Considering the time required for serialization/deserialization, using
> > something like webORB would improve parsing time, as it uses a binary
> > format which can be parsed more easily than a text format. But unless
> > you're using large datasets/doing lots of web service calls, the
> > advantages are probably negligible.
> >
> > Are you transmitting everything in the array collection back to the
> > web service, or just the IDs of the selected rows? Transferring
> > everything including the row data would remove the need for another
> > database hit, but for large datasets, that could be quite a bit of
> > traffic. I'd say it would be better just to transmit the IDs back to
> > the webservice, and let the webservice hit the database for the row
> > data (some caching on the server-side would help too).
> >
> > 2009/6/8 Angelo Anolin <angelo_ano...@...
> > <mailto:angelo_anolin%40yahoo.com>>:
> > >
> > >
> > >
> > > Hi Sam,
> > >
> > > Thanks for your reply.
> > >
> > > As of now, I actually prefer to utilize what I know on .NET and what
> > I am
> > > learning on Flex. Adding another utility (Web Orb) in my learning
> > process
> > > may complicate things a bit. I might consult this later if I feel
> > that the
> > > needs for is getting tremendous.
> > >
> > > Anyway, I am actually able to generate the report from what I am
> > currently
> > > doing (no error encountered), where the ArrayCollection I am parsing
> > into a
> > > delimited string, passing the string to the webservice call, and
> > letting the
> > > webservice de-serialize the string to populate a Crystal report document
> > > which I subsequentlt display in another browser window which I call
> > from the
> > > Flex application.
> > >
> > > I mentioned that I did not feel it is the "BEST" way because I am
> > literally
> > > storing all datagrid (report) information in a string variable.
> > Assuming
> > > for example that the data displayed in the datagrid is quite huge, then
> > > creating the delimited string would take some time and additional
> > processing
> > > time could also be consumbed by the back end web service to parse
> > the string
> > > and populate the report.
> > >
> > > As of now, this is what the application does.
> > > 1. Flex App calls a webservice to retrieve data.
> > > 2. WebService responds by sending back a dataset which is returned as a
> > > string (via Dataset.GetXML method of .NET).
> > > 3. Flex App gets the service response, converts the string into an XML.
> > > 4. Flex App converts the XML data into an ArrayCollection which is
> > bound to
> > > the datagrid.
> > > * Please note that I used array collection here for the search/filter
> > > functionality of the datagrid.
> > > 5. When generating print out of the data displayed in the datagrid, Flex
> > > would then serialize the ArrayCollection into a delimited string and
> > send it
> > > to the web service.
> > > 6. Web Service would then de-serialize (or parse) the string, populate a
> > > .NET dataset which is the datasource for the Crystal report.
> > > 7. Crystal report is bound and PDF report is generated.
> > > 8. Flex displays via external javascript call the PDF report generated.
> > >
> > > Is there a better way for the ArrayCollection to be sent to the
> > webservice,
> > > the webservice in turn would just convert it to dataset and the
> > dataset is
> > > immediately bound to the Crystal report?
> > >
> > > Thanks.
> > >
> > > Regards,
> > >
> > > Angelo
> > > ________________________________
> > > From: Sam Lai <samuel....@... <mailto:samuel.lai%40gmail.com>>
> > > To: flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com>
> > > Sent: Monday, 8 June, 2009 8:49:36
> > > Subject: Re: [flexcoders] Flex and .NET
> > >
> > > 2009/6/8 Angelo Anolin <angelo_anolin@ yahoo.com>:
> > >
> > >> I feel that this is probably not the "BEST" way of doing this. I tried
> > >> initially to pass an XML delimmited string, but .NET seems to read XML
> > >> differently( ?) from Flex.
> > >
> > > I'd say XML would be a good way of doing it. What kind of errors are
> > > you getting, and how are you making the web service call?
> > >
> > > The other option is to use AMF, a native messaging format for
> > > Flash/Flex. This I believe would save you the effort of serializing
> > > and deserializing - it does it for you, among other things.
> > >
> > > http://www.themidni ghtcoders. com/products/ weborb-for-
> > net/overview. html
> > >
> > >
> > >
> > >
> >
> >
>
