Estimating fees on empty Shelley wallet takes 5-6s

[piotr-iohk]

Context

According to benchmarks since nb #636 (revision 76b3a6d) fee estimation time increased from ~1.5s to 5-6s on empty Shelley wallet.

Information	-
Version	2020.9.11 (git revision: ffeca1d9e0f302111588c7890785051b6cc6b0da)
Platform	Linux, all?
Installation	from source

Steps to Reproduce

1. Trigger fee estimation on empty Shelley wallet

Expected behavior

Should return not_enough_money right away.

Actual behavior

Takes 5-6s on nightly benchmarks.
Note for comparison, it takes ~3-4s for 0.4% seq wallet.

(On my local machine I got ~3s for empty wallet, and ~1s on small wallet with funds)

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Resolution

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QA

[Anviking]

Looking at the commit history around 76b3a6d https://github.com/input-output-hk/cardano-wallet/commits/master?after=647632e17f1a4add822ab76aef01ba6772a7b813+244&branch=master,

it seems #2112 was merged just before, which seems suspicious

[piotr-iohk]

Resolved with #2348.

benchmark results on branch -> https://buildkite.com/input-output-hk/cardano-wallet-nightly/builds/743.

E.g.:

1-wallets-to-0.1:
"estimateFeesTime":"8.950 ms"
used to be = 9.975 s

100-wallets-to-0.01:
"estimateFeesTime":"117.2 ms"
used to be = 19.7 s