Fixes Deep Dive Docs Bounty Issue 598

[rahul-soshte]

Added a new category called Network Insights, in the Developer Tools, and added the link to the fee simulator tool, along with a nice description
Resolves issue #598

[briwylde08]

Awesome work! We'll get this assigned and reviewed 🎉

[sisuresh]

Hey @rahul-soshte, thanks for contributing. Some feedback and a request - Under estimation with Write Ledger Entries set to 5, it returns 5 xlm. It looks like the values make more sense once they're all filled in. The estimation tab is also missing parameters for rent.

Can you please demonstrate the calculations are right by making sure the result from Simulation matches up with what Estimation returns? I found a transaction on testnet, put it into simulation, and then put those values into Estimation, which returned a lower value (I'm guessing because the rent calculation was missing). Another thing to look into - the writeBytes shown on stellar.expert for the transaction I linked when you expand the arrows on the right is 3x higher than what your Simulation returns. I'm not sure why they're so different.

[rahul-soshte]

Thank you @sisuresh for the feedback, I will dig more deep with the calculations and check what's missing in the overall calculations.

[sisuresh]

I'd also recommend taking a look at https://github.com/stellar/rs-soroban-env/blob/main/soroban-env-host/src/fees.rs.

[rahul-soshte]

Hi @sisuresh,

So I have researched the link that you gave, read the fee docs again, making sure what I am interpreting is correct. I have even open sourced the GUI repo ( used the laboratory frontend code as a base ), so it is much more faster to get feedback. Here are the changes/clarifications since the last time we talked,

1. I am sending the writeBytes() from what I get from the the simulation endpoint properly here ( used the XDR for the testnet transaction that you sent ), might have been some bug in the stellar.expert

2. What I am showing in the simulate fees route is the max resource fee. Do I need to add the actual estimate here as well?

3. For the testnet tx that you sent, I am getting the fees bit close to the actual fee charged in the estimation. The actual fee charged was
   0.0357842 but I am getting around, 0.0319042, so I am close but don't know what mistake I am making

4. In the rent calculation form, I have provided for a setting of the current ledger, and also you can add a ledger entry based on the following parameters of a ledger entry,
   a. Persistent or Temporary
   b. Old Size and New Size
   c. Old Live Until Ledger, New Live Until Ledger.
   I am sending this data in the fee simulation as well.

5. Please do tell me what more mistakes I might be making as there are some nuances still involved here, which I am missing, or I might be making some small mistakes, which get the estimation slightly off.
   Rent Estimation GUI Code
   Other Resource Parameters Estimation GUI Code
   Simulation GUI code

@briwylde08 I am working on this tirelessly, it's just that there are lot many nuances than I thought. I am committed to completing this, and later extending it's scope so that it can be a good SCF project and also for maintenance of the GUI app, ad infinitum, since as Stellar grows, this GUI will need tweaks as well, based on the protocol changes.

[briwylde08]

Hi @rahul-soshte! I completely respect that this is not an easy task and appreciate your continued work on it - a tool like this is super valuable to the ecosystem. I have no issues with this qualifying for the bounty (probably worth more than originally posted) and I agree that it would also make an awesome SCF project. I tagged @sisuresh for review again and the team will be in touch with feedback! Thanks again for your work!

[sisuresh]

Hey @rahul-soshte, thanks for the improvements. I put the testnet tx into Simulation, which returned the following -

"Fees":
{
"Max Resource fee (XLM)":
0.0372393,
"Max Estimated Fee (XLM)":
"0.0372493",
},

but Estimation returned 0.0293787 XLM. Do you know why there's a difference? Is that expected? I'm using 1398989 as the current ledger for both.

[rahul-soshte]

Hey @sisuresh Sorry for the delay got caught up in travelling somewhere and fell sick a bit.

So yeah I mean initially in the simulation, I was showing the max fee that simulation Endpoint returned instead of the actual estimated fee, which is wrong and confusing UX. So I now have fixed it. The simulation's estimated fee should match the direct estimation considering all the resource + rent value in the UI.

If you can find more bugs please do let me know. The Testnet tx we were using, has been wiped up by the network reset.

I am still working on fixing any bugs, and gonna research on how simulationTransaction endpoint is calculating the max resource fee. It so much higher than the actual fee charged. I am not sure why.
For example check this transaction
https://stellar.expert/explorer/testnet/tx/9947144265728
Here the actual fee charged is 0.005939
and the max fee is 0.0106407 which is way higher.

[rahul-soshte]

I will have to read these CAP docs on fees, they could help me in making this fee estimator the most perfect and they would have esoteric knowledge that isn't available in the stellar docs
https://github.com/stellar/stellar-protocol/blob/master/core/cap-0046-07.md
https://github.com/stellar/stellar-protocol/blob/master/core/cap-0046-08.md
https://github.com/stellar/stellar-protocol/blob/master/core/cap-0046-09.md
https://github.com/stellar/stellar-protocol/blob/master/core/cap-0046-10.md