No processing of transactions during a decommit

[v0d1ch]

fix #1526

Related specification PR cardano-scaling/hydra-formal-specification#7

Why?

• New L2 transactions fail when decommit is in flight because we try to re-apply the local decommit tx

What

• Make sure the new snapshots are created only if the version is matched
• Any pending decommit needs to match with the decommit in confirmed snapshot thus preserved in the next snapshot/s until it is observed.

---

• CHANGELOG updated or not needed
• Documentation updated or not needed
• Haddocks updated or not needed
• No new TODOs introduced or explained herafter

[github-actions]

Transaction costs

Sizes and execution budgets for Hydra protocol transactions. Note that unlisted parameters are currently using arbitrary values and results are not fully deterministic and comparable to previous runs.

Metadata
Generated at	2024-08-08 07:21:12.737612851 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νInitial	2fac819a1f4f14e29639d1414220d2a18b6abd6b8e444d88d0dda8ff	3799
νCommit	2043a9f1a685bcf491413a5f139ee42e335157c8c6bc8d9e4018669d	1743
νHead	bd9fad235c871fb7f837c767593018a84be3083ff80f9dab5f1c55f9	10194
μHead	c8038945816586c4d38926ee63bba67821eb863794220ebbd0bf79ee*	4607

• The minting policy hash is only usable for comparison. As the script is parameterized, the actual script is unique per head.

Init transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	5186	5.61	2.21	0.44
2	5390	7.31	2.90	0.47
3	5591	8.64	3.42	0.49
5	5994	11.39	4.51	0.54
10	6996	18.06	7.14	0.66
56	16246	81.47	32.22	1.76

Commit transaction costs

This uses ada-only outputs for better comparability.

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	557	10.52	4.15	0.29
2	747	13.86	5.65	0.34
3	933	17.33	7.20	0.38
5	1307	24.65	10.44	0.48
10	2252	45.22	19.36	0.75
20	4124	95.99	40.76	1.40

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	549	21.49	8.43	0.41
2	114	659	33.93	13.42	0.55
3	169	773	45.25	18.13	0.68
4	227	883	60.03	24.21	0.85
5	282	989	78.32	31.74	1.06
6	338	1100	98.21	39.96	1.28

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	626	17.96	7.88	0.38
2	824	20.18	9.46	0.42
3	1042	22.60	11.13	0.46
5	1268	25.44	13.69	0.51
10	1975	32.34	19.97	0.64
50	7774	95.85	73.84	1.80

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	640	20.98	9.39	0.42
2	732	22.07	10.47	0.44
3	870	23.54	11.88	0.46
5	1171	26.86	15.00	0.53
10	1941	34.66	22.56	0.68
50	8100	99.04	83.82	1.91

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	670	27.14	11.66	0.48
2	906	29.40	13.58	0.53
3	894	30.22	14.32	0.54
5	1222	34.23	17.71	0.61
10	2106	44.80	26.82	0.80
39	6438	98.90	73.55	1.76

Abort transaction costs

There is some variation due to the random mixture of initial and already committed outputs.

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	5081	17.43	7.59	0.57
2	5181	28.46	12.48	0.70
3	5314	41.53	18.31	0.85
4	5520	59.69	26.52	1.07
5	5684	79.01	35.23	1.29
6	5679	95.15	42.35	1.47

FanOut transaction costs

Involves spending head output and burning head tokens. Uses ada-only UTxO for better comparability.

Parties	UTxO	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
5	0	0	5022	7.95	3.36	0.46
5	1	56	5055	8.88	3.99	0.47
5	5	285	5192	13.60	6.92	0.54
5	10	568	5361	19.06	10.39	0.62
5	20	1135	5698	30.38	17.51	0.77
5	30	1708	6042	42.10	24.80	0.94
5	40	2277	6382	53.43	31.93	1.09
5	50	2847	6721	64.37	38.89	1.25
5	81	4611	7773	99.53	61.01	1.74

End-to-end benchmark results

This page is intended to collect the latest end-to-end benchmark results produced by Hydra's continuous integration (CI) system from the latest master code.

Please note that these results are approximate as they are currently produced from limited cloud VMs and not controlled hardware. Rather than focusing on the absolute results, the emphasis should be on relative results, such as how the timings for a scenario evolve as the code changes.

Generated at 2024-08-08 07:23:50.149991122 UTC

Baseline Scenario

Number of nodes	1
Number of txs	3000
Avg. Confirmation Time (ms)	5.201270347
P99	8.308878819999995ms
P95	6.903310199999998ms
P50	5.004944999999999ms
Number of Invalid txs	0

Three local nodes

Number of nodes	3
Number of txs	9000
Avg. Confirmation Time (ms)	23.628713598
P99	47.552444290000075ms
P95	31.92053799999999ms
P50	21.761108999999998ms
Number of Invalid txs	0

[github-actions]

Test Results

466 tests  +2   459 ✅ +2   17m 30s ⏱️ + 1m 9s
149 suites ±0     7 💤 ±0 
  5 files   ±0     0 ❌ ±0 

Results for commit 5753598. ± Comparison against base commit 7e5730b.

♻️ This comment has been updated with latest results.

[ch1bo]

Only bug I found was the require/wait mix

Could align it more with the spec though.

Also, the spec is now in another repo so we need two PRs. This PR then should point to the new, updated spec in its flake inputs.

[ch1bo]

Must refer to an updated formal spec flake input. I'll review it again in more detail tomorrow

[ch1bo]

Tested this manually on a slow local devnet and can't reproduce the behavior from the bug - fixed! 💪

Side note though: If we have multiple snapshots with a utxoToDecommit, the hydra-node seems to submit it on each snapshot confirmation, resulting eventually to a race of multiple decrementTxs and errors reported like:

TxValidationErrorInCardanoMode (ShelleyTxValidationError ShelleyBasedEraBabbage (ApplyTxError (UtxowFailure (AlonzoInBabbageUtxowPredFailure (ExtraRedeemers [Alonz
oSpending (AsIx {unAsIx = 0})])) :| [UtxowFailure (AlonzoInBabbageUtxowPredFailure (PPViewHashesDontMatch (SJust (SafeHash \"10f0625aedbf7ada32774b7574fb8223808451d22806d3693f31b76cbbc6c3fa\")) (SJust (SafeHash \"5e13ca4c11ff1467512cde99f5e300f7dc19f39099fd83b8b3e35b80427914f8\")))),UtxowFailure (UtxoFailure (AlonzoInBabbageUtxoPredFailure (ValueNotConservedUTxO (MaryValue (Coin 0) (MultiAsset (fromList []))) (MaryValue (Coin 86182523) (MultiAsset (fromList [(PolicyID {policyID = ScriptHash \"3bc4890827e9784f22ee115016d5dcaf073b407175398b04f8f23ae0\"},fromList [(\"4879647261486561645631\",1),(\"f8a68cd18e59a6ace848155a0e967af64f4d00cf8acee8adc95a6b0d\",1)])])))))),UtxowFailure (UtxoFailure (AlonzoInBabbageUtxoPredFailure (BadInputsUTxO (fromList [TxIn (TxId {unTxId = SafeHash \"9762190e385ad32de7eafd14044748d98cb6cbfc9ea59ab4e11faa7fedf450c4\"}) (TxIx {unTxIx = 0}),TxIn (TxId {unTxId = SafeHash \"9762190e385ad32de7eafd14044748d98cb6cbfc9ea59ab4e11faa7fedf450c4\"}) (TxIx {unTxIx = 2})])))),UtxowFailure (UtxoFailure (AlonzoInBabbageUtxoPredFailure NoCollateralInputs)),UtxowFailure (UtxoFailure (AlonzoInBabbageUtxoPredFailure (InsufficientCollateral (DeltaCoin 0) (Coin 2586266))))])))