HTTP chain observer

[ch1bo]

Extends hydra-chain-observer to submit observations to a hydra-explorer instance with the new observer API.

See https://github.com/cardano-scaling/hydra-explorer/blob/observer-backend/README.md#architecture for an architectural overview.

• 🔍 Adds --explorer option to hydra-chain-observer which submits observations using HTTP. This uses the OnChainTx type, so there are new roundtrip tests and golden files.

• 🔍 Make hydra-chain-observer aware of its --version (also via embedding git revs using nix).

• 🔍 Switch on --node-socket or --blockfrost-project-path in hydra-chain-observer instead of subcommands. This allows us to re-use more code and the help text becomes easier to understand. See hydra-chain-observer/README.md for how to invoke the binary now.

• 🔍 Extracts a common.yaml from API definitions so we can reference it from hydra-explorer API specs / schemas

• 🔍 Moves observation code from hydra-node to hydra-tx, this improves dependency closure for hydra-explorer, especially once we move Hydra.Chain out of hydra-node (e.g. by inverting the dependency of hydra-chain-observer?)

  • This requires

• Adds orphan instances to hydra-cardano-api as needed by the hydra-explorer, see Observer API backend hydra-explorer#18

TODO:

• Client-side serialization tests against observer openapi

---

• CHANGELOG updated
• Documentation updated (README, no user guide)
• Haddocks updated
• New TODOs explained herafter

[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	-	-	-	-
44	-	-	-	-

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	-	-	-	-	-
9	-	-	-	-	-
10	-	-	-	-	-

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	+0.38	+0.09	-
5	-	$${\color{green}-0.39}$$	$${\color{green}-0.09}$$	-
10	-	+0.38	+0.1	-
43	-	-	-	-

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
45	-	-	-	-

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
41	-	-	-	-

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
33	-	-	-	-

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)	-	-	-	-	-
(40, 10)	-	-	-	-	-
(41, 10)	-	-	-	-	-

[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	2025-01-31 23:25:07.694218213 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	5350e9d521552ebfd9e846fd70c3b801f716fc14296134ec0fb71e97	14492
μHead	6b49dc4e571207d615dba01996548cb610b0caa85c30423d169d0091*	5612
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	6162	10.17	3.24	0.53
2	6366	12.04	3.82	0.56
3	6567	14.57	4.64	0.59
5	6969	18.74	5.96	0.65
10	7974	28.50	8.99	0.80
44	14811	98.38	30.98	1.82

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	738	3.38	1.73	0.22
3	923	4.36	2.33	0.24
5	1277	6.41	3.60	0.28
10	2176	12.13	7.25	0.40
54	10045	98.61	68.52	1.88

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	525	24.20	7.07	0.42
2	114	640	32.00	9.33	0.50
3	170	747	42.14	12.15	0.61
4	227	858	51.93	14.87	0.71
5	281	969	56.79	16.41	0.77
6	340	1081	67.52	19.44	0.88
7	394	1192	76.78	22.16	0.98
8	450	1303	87.23	25.07	1.09

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	1799	24.13	8.02	0.48
2	1886	24.21	8.68	0.49
3	2060	26.64	10.19	0.53
5	2417	32.03	13.32	0.61
10	3157	40.93	19.63	0.76
42	7904	96.11	59.35	1.70

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	625	22.72	7.33	0.41
2	763	23.93	8.35	0.44
3	898	25.66	9.49	0.47
5	1213	29.50	11.90	0.53
10	1931	38.05	17.61	0.67
42	6777	98.36	55.87	1.65

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	691	27.03	8.73	0.46
2	818	28.68	9.92	0.49
3	991	32.67	11.86	0.54
5	1218	36.00	14.23	0.60
10	1917	45.17	20.52	0.75
41	6517	99.00	59.25	1.66

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	683	33.35	10.42	0.52
2	829	35.33	11.70	0.56
3	941	37.29	12.96	0.59
5	1325	42.38	16.07	0.67
10	1958	52.12	22.38	0.82
31	5229	98.19	51.59	1.55

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	6078	26.08	8.83	0.69
2	6168	34.73	11.74	0.79
3	6232	42.42	14.28	0.87
4	6422	52.01	17.55	0.98
5	6522	61.06	20.55	1.08
6	6775	71.50	24.26	1.20
7	6673	72.14	24.32	1.20
8	6837	84.92	28.61	1.34
9	6993	92.03	31.10	1.43

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	6163	17.66	6.02	0.61
10	1	57	6196	20.15	7.00	0.64
10	5	284	6332	27.82	10.09	0.73
10	40	2280	7525	97.12	37.93	1.54
10	42	2390	7588	99.94	39.10	1.57

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 2025-01-31 23:28:07.652836981 UTC

Baseline Scenario

Number of nodes	1
Number of txs	300
Avg. Confirmation Time (ms)	4.395575290
P99	9.001001309999994ms
P95	5.614212500000006ms
P50	4.1872195ms
Number of Invalid txs	0

Three local nodes

Number of nodes	3
Number of txs	900
Avg. Confirmation Time (ms)	23.592436174
P99	114.81169518ms
P95	31.082840649999998ms
P50	20.7123965ms
Number of Invalid txs	0