NullReferenceExceptions - API Reliability? API Key Permissions? Better logic filters?

[jmscraig]

If I have just one coin or fifty coins the Console app crashes within 2-10 minutes.

Running the Console published or in debug mode consistently surfaces Null Reference Exceptions.

==== some text deleted.

• A Credential problem related to the other issue posted?

• Pilot error?

• API Key permissions problem? The API Key used is limited to "General" read-only permissions. Trade and Withdrawal are not enabled.

Thanks! James

================ 02-10-21022 Update:

-Trying to solve a bug is a great way to learn a bit of code

-It appears that despite the Credential Tool error message the API key was saved and is working successfully

Regarding the Null Reference Exception that appear after running the console for 2 - 10 mins:

• I am using either the default 10 or more commonly using just 3-4 symbols so I am testing with a lighter load than implied default of 10 symbols.

• I am commonly seeing Null Reference Exceptions at these line numbers in the Console project's program.cs: 1124, 1128, 1190, 1246 and 1327. See doc image and txt file attached below.

• I added an image of the KuCoinNet Console after freezing upon a Null Ref Exception while running just three symbols.

• In all cases the first NullRefException is thrown at Console program.cs line # 1124 or 1128 1124 lock (a.Level3OrderBook.LockObject) >> NullReferenceException 1128 lock (b.Level3OrderBook.LockObject) >> NullReferenceException

The image below shows that a.Level3OrderBook is NULL as the cause of the exception.

This image shows that in sortobs[1] (BTC) the Level3OrderBook value was NULL so is no surprise a.Level3OrderBook.LockObject was found to be NULL.

• The other common List sortobs dependent NREx program.cs line numbers are visible in the attached image and RTF file.

Root Cause? Possible Fixes?

• The current question is why is Observers item.Level3OrderBook frequently null and can that be fixed.

• If consistent inclusion of tem.Level3OrderBook can not be fixed then the question turns to what do we do to find a reliable resolution.

• What I tried so far: In Line# 1118 I added a null reference check item.Level3OrderBook as a condition for inclusion in the sortobs list but the did not work out well.

Your thoughts on the assessment and do you have a recommendation for a fix?

Thanks!

James

KuCoinNET Sample Console Program-NULL-EXCEPTIONS-.txt

==== UPDATE: Feb 12th 2022

I spent a few minutes on this again today. All of the Null Ref Exception trouble I have seen is related to the intermittent null value for Level3Orderbook within Observers and sortobs entries.

Still not sure if this is: 1) A Websock feed input quality issue from the Kucoin side 2) An artifact that occurs when exchange transaction volume for a token gets very light 3) A bug in the logic loading Observers and/or the logic loading sortobs.

Any insight?

James

[nmoschkin]

I believe this issue has been resolved. Level 3 has been completely deprecated and there may have been some correlation here.

However, notably... the Console app is not the project, it is the sample. I am not as concerned with bugs in the console app as I am with bugs in the base library.

The peculiar reason the order book was disappearing was probably a connection was reset or an order book fell out of alignment and something on the front end was catching it in an inconsistent state.