Not observe invalid transactions

[ch1bo]

Fixes hydra-tx observations used in hydra-node and hydra-explorer to never make an observation on invalid transactions.

This avoids situations where adversaries may create transactions that do not pass on-chain validators, but deliberately mark the transaction with isValid = false to trick off-chain components.

---

• CHANGELOG update not needed
• Documentation update not needed
• Haddocks update not needed
• No new TODOs introduced

[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	2025-04-16 19:54:47.64085825 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νInitial	c8a101a5c8ac4816b0dceb59ce31fc2258e387de828f02961d2f2045	2652
νCommit	61458bc2f297fff3cc5df6ac7ab57cefd87763b0b7bd722146a1035c	685
νHead	0e35115a2c7c13c68ecd8d74e4987c04d4539e337643be20bb3274bd	14756
μHead	57166715eadb8d3135964325c016eea546c21e1c0aae974ca67df9a5*	5541
νDeposit	ae01dade3a9c346d5c93ae3ce339412b90a0b8f83f94ec6baa24e30c	1102

• 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	6091	11.23	3.50	0.53
2	6292	13.04	4.04	0.56
3	6493	15.28	4.73	0.59
5	6897	20.34	6.30	0.66
10	7904	31.40	9.68	0.82
40	13936	98.39	30.22	1.78

Commit transaction costs

This uses ada-only outputs for better comparability.

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	561	2.44	1.16	0.20
2	743	3.38	1.73	0.22
3	923	4.36	2.33	0.24
5	1277	6.41	3.60	0.28
10	2170	12.13	7.25	0.40
54	10059	98.61	68.52	1.88

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	525	25.64	7.39	0.43
2	114	636	34.81	9.96	0.53
3	171	751	45.86	13.00	0.65
4	226	858	49.99	14.38	0.70
5	283	969	60.72	17.40	0.81
6	338	1081	79.34	22.25	1.00
7	396	1192	88.85	24.89	1.10
8	450	1303	98.25	27.48	1.20

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	1807	25.12	8.24	0.49
2	1886	25.98	9.08	0.51
3	2059	28.65	10.64	0.55
5	2364	32.51	13.26	0.61
10	3176	43.44	20.19	0.79
36	7145	97.54	55.07	1.65

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	617	23.71	7.55	0.42
2	730	24.81	8.48	0.44
3	824	25.31	9.28	0.46
5	1129	30.37	12.03	0.53
10	1919	41.59	18.46	0.70
38	6046	94.64	51.72	1.55

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	711	29.19	9.23	0.48
2	775	32.84	10.92	0.53
3	949	32.77	11.64	0.54
5	1377	40.77	15.64	0.65
10	2001	50.54	21.96	0.80
31	5193	96.83	50.84	1.53

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	696	35.95	11.01	0.55
2	768	37.49	12.02	0.57
3	1058	41.69	14.26	0.64
5	1248	45.21	16.53	0.69
10	2025	57.32	23.70	0.87
27	4645	99.41	48.43	1.51

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	5987	28.20	9.30	0.71
2	6138	38.45	12.72	0.82
3	6206	46.51	15.35	0.91
4	6445	57.94	19.21	1.04
5	6372	58.51	19.24	1.04
6	6805	78.78	26.11	1.27
7	6895	87.79	29.18	1.37
8	6993	96.66	31.96	1.47
9	6959	95.27	31.43	1.45

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 ₳
10	0	0	6091	20.58	6.77	0.63
10	5	285	6261	30.97	10.82	0.75
10	10	569	6430	40.96	14.72	0.87
10	38	2162	7381	99.70	37.55	1.55

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 2025-04-16 19:56:14.407067516 UTC

Baseline Scenario

Number of nodes	1
Number of txs	300
Avg. Confirmation Time (ms)	4.476598286
P99	6.682495559999993ms
P95	5.108360500000001ms
P50	4.1440725ms
Number of Invalid txs	0

Memory data

Time	Used	Free
2025-04-16 19:54:58.658304677 UTC	908M	6323M
2025-04-16 19:55:03.65829799 UTC	1026M	6112M
2025-04-16 19:55:08.65826024 UTC	1029M	6110M
2025-04-16 19:55:13.658338883 UTC	1029M	6109M
2025-04-16 19:55:18.658305667 UTC	1037M	6101M
2025-04-16 19:55:23.658310364 UTC	1038M	6100M

Three local nodes

Number of nodes	3
Number of txs	900
Avg. Confirmation Time (ms)	31.210330968
P99	72.91683242999997ms
P95	54.807220650000005ms
P50	27.5184135ms
Number of Invalid txs	0

Memory data

Time	Used	Free
2025-04-16 19:55:37.49487945 UTC	965M	6182M
2025-04-16 19:55:42.496047425 UTC	1210M	5930M
2025-04-16 19:55:47.497614397 UTC	1267M	5808M
2025-04-16 19:55:52.494973485 UTC	1273M	5764M
2025-04-16 19:55:57.494983348 UTC	1275M	5762M
2025-04-16 19:56:02.494915408 UTC	1279M	5757M
2025-04-16 19:56:07.494902967 UTC	1279M	5756M
2025-04-16 19:56:12.49493856 UTC	1281M	5753M

[github-actions]

Transaction cost differences

Script summary

Name	Size (Bytes)
νInitial	-
νCommit	-
νHead	-
μHead	-
νDeposit	-

Init transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
40	-	-	-	-

Commit transaction costs

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
54	-	-	-	-

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-	-
2	-	-	-	-	-
3	-	-	-	-	-
4	-	-	-	-	-
5	-	-	-	-	-
6	-	-	-	-	-
7	-	-	-	-	-
8	-	-	-	-	-

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	$${\color{green}-0.39}$$	$${\color{green}-0.09}$$	-
10	-	$${\color{green}-0.39}$$	$${\color{green}-0.09}$$	$${\color{green}-0.01}$$
37	-	+0.38	+0.09	-

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
40	-	-	-	-

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
34	-	-	-	-

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
27	-	-	-	-

FanOut transaction costs

UTxO, Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
(0, 10)	-	-	-	-	-
(1, 10)	-	-	-	-	-
(5, 10)	-	-	-	-	-
(10, 10)	-	-	-	-	-
(20, 10)	-	-	-	-	-
(37, 10)	-	-	-	-	-

[ffakenz]

👼