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IDProjectCategoryView StatusDate SubmittedLast Update
0004131.NET APIPerformance Problempublic2018-01-22 02:042021-02-03 04:37
ReporterDaniel Godwin Assigned ToMartin Regen  
PriorityhighSeverityblockReproducibilityalways
Status assignedResolutionopen 
PlatformPCOSWindowsOS Version8.1
Summary0004131: Using the OPC .NET API assemblies to browse an OPC server address space can take over 30 minutes.
Description

When browsing an OPCHDA server using OPC .NET API, with a flat list of 1000 items, it takes about 20 seconds to return.

var children = lBrowser.Browse(null, 0, out position);

If I browse the same server using the Matrikon OPCHDA explorer, which I assume uses the standard COM interface, it only takes a couple of seconds.

When browsing a server with a flat list of 100,000 items, it takes over 30 minutes. Again, using the COM interface, it takes about 40 seconds.

It is not feasible for a user to wait 30 minutes to see the list of items available on the server. Can this performance be improved?

Steps To Reproduce

Configure an OPCHDA server with 100,000 items (obviously don't need this many to see the difference between .NET and COM interface performance).
Browse the address space using the OPC Foundation sample OPCHDA client.

Additional Information

Looking at the .NET API code, I can see that for each item on the server, the name is retrieved, and then for each item, GetItemId() is called, and this appears to be where the slow down is occurring.

At a minimum, could the API be improved to allow just the names to be returned, so users could then choose a subset of items for which they need the full itemId?

Ultimately though, a user may still want the itemId of every item on the server (in order to retrieve data), and so a 30 minute wait time is not acceptable.

TagsNo tags attached.

Activities

Randy Armstrong

2018-01-22 02:26

administrator   ~0008845

Servers with flat lists of 100,000 items are asking for trouble. That number of items should be divided into folders.

That said, if you have to deal with such poorly designed servers you may be better off working with the GetEnum interface directly instead of using the .NET API.

The code base is no longer mainatined so design improvements/feature requests are not likely to added. You should have the source code you need.

Daniel Godwin

2018-01-30 08:16

reporter   ~0008851

Hi Randy,
I have no problem modifying the source code. Are there any licensing agreements we need to be aware of or are we free to modify and distribute?

Also, currently our application is installing the merge module that contains the OpcNetApi and OpcNetApi.Com assemblies, OPC .NET API 4.5 Merge Module. But now we'll need to overwrite the two dlls in the GAC with our modified versions. Would that be the best approach?
Thanks,
Daniel

Issue History

Date Modified Username Field Change
2018-01-22 02:04 Daniel Godwin New Issue
2018-01-22 02:26 Randy Armstrong Note Added: 0008845
2018-01-22 02:26 Randy Armstrong Assigned To => Randy Armstrong
2018-01-22 02:26 Randy Armstrong Status new => feedback
2018-01-30 08:16 Daniel Godwin Note Added: 0008851
2018-01-30 08:16 Daniel Godwin Status feedback => assigned
2021-02-03 04:37 Randy Armstrong Assigned To Randy Armstrong => Martin Regen