Remove multicast reqSn step on decrementTx

[ffakenz]

This PR reduces the number of network messages in the presence of decrementTx, by avoiding unnecessary snapshot signature round-trips between peers.

Removed multicast reqSn step on decrementTx from chain.

Since it is triggered by a chain observation, we expect/assume everyone will eventually observe it and continue cooperating.

---

• 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	2024-07-29 17:17:03.342501415 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	7ae23bc9f0833a5689b9fc812dd92fbe9dac881a632f14b28e8eb8db	10193
μHead	3ebfb5b268e0c94200e2c8a8eeebf704aabf303a769af602edb3603a*	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	5188	5.75	2.27	0.44
2	5390	7.36	2.91	0.47
3	5588	8.41	3.32	0.49
5	5993	11.12	4.39	0.54
10	6999	18.30	7.24	0.66
56	16250	81.43	32.21	1.76

Commit transaction costs

This uses ada-only outputs for better comparability.

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	559	10.52	4.15	0.29
2	749	13.86	5.65	0.34
3	934	17.33	7.20	0.38
5	1310	24.65	10.44	0.48
10	2243	45.22	19.36	0.75
20	4119	95.99	40.76	1.40

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	549	22.14	8.66	0.42
2	114	659	32.17	12.76	0.53
3	170	769	44.11	17.70	0.67
4	227	883	60.85	24.51	0.86
5	283	989	72.19	29.45	0.99
6	339	1100	92.68	37.90	1.22

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	645	17.96	7.90	0.38
2	813	20.38	9.54	0.42
3	848	19.24	9.80	0.41
5	1238	25.56	13.74	0.51
10	1981	32.72	20.19	0.65
49	8043	97.89	73.83	1.83

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	653	21.02	9.41	0.42
2	837	22.57	10.96	0.45
3	918	23.96	12.22	0.47
5	1191	26.66	14.93	0.53
10	1991	35.38	23.02	0.69
49	7894	97.30	82.44	1.88

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	674	27.18	11.67	0.48
2	811	28.94	13.18	0.51
3	1046	31.55	15.39	0.56
5	1292	34.77	18.19	0.62
10	2092	44.50	26.55	0.79
39	6290	98.22	72.75	1.75

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	4978	13.91	5.81	0.52
2	5205	28.47	12.49	0.70
3	5402	43.89	19.49	0.88
4	5407	57.07	25.22	1.03
5	5748	80.00	35.75	1.31
6	5782	97.51	43.45	1.51

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	57	5056	9.28	4.16	0.48
5	5	283	5191	13.80	7.01	0.54
5	10	570	5362	19.06	10.39	0.62
5	20	1140	5703	30.38	17.51	0.77
5	30	1708	6042	41.70	24.63	0.93
5	40	2278	6382	53.43	31.93	1.09
5	50	2849	6724	64.37	38.89	1.25
5	80	4555	7739	98.00	60.13	1.72

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 2024-07-29 17:20:06.167497031 UTC

Baseline Scenario

Number of nodes	1
Number of txs	3000
Avg. Confirmation Time (ms)	4.188430699
P99	6.779493459999981ms
P95	5.1406894ms
P50	4.020124ms
Number of Invalid txs	0

Three local nodes

Number of nodes	3
Number of txs	9000
Avg. Confirmation Time (ms)	23.575620042
P99	117.57211335000004ms
P95	32.2091482ms
P50	20.7671535ms
Number of Invalid txs	0

[github-actions]

Test Results

464 tests   - 1   457 ✅  - 1   17m 57s ⏱️ +28s
149 suites ±0     7 💤 ±0 
  5 files   ±0     0 ❌ ±0 

Results for commit 978152f. ± Comparison against base commit e1745f2.

This pull request removes 1 test.

Hydra.HeadLogic/Coordinated Head Protocol/Decommit ‑ emits snapshot onDecrementTx with cleared decommitTx

♻️ This comment has been updated with latest results.

[ch1bo]

It's a bit unfortunate that this is only one commit. In the end the rename should have been a separate PR.

[ch1bo]

Good catch and thanks for explaining why in the PR description!