Test partial fanout recovers funds with an unburned token

[vrom911]

---

• 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 cost differences

No cost or size differences found

[github-actions]

End-to-end benchmark differences

Comparing this PR (new) against master (old). Numbers come from cloud VMs, so changes under 5% are shown as ≈ and are likely run-to-run noise rather than a real regression or improvement. 🟢 = improvement, 🔴 = regression; uncolored rows are neutral measures reported for context.

Sustained load (3 nodes, 3x5000 txs)

Metric	master	PR	Δ
End-to-end TPS (tx/s)	483.69	446.39	🔴 -37.30 (-7.7%)
Sustained TPS (tx/s)	902.35	914.02	≈ +11.67 (+1.3%)
Backlog drain time (s)	30.30	32.90	🔴 +2.60 (+8.6%)
Snapshots per second (/s)	0.55	0.51	-0.04 (-7.3%)
Avg txs per snapshot	882.40	882.40	≈ +0.00 (+0.0%)
Avg. Confirmation Time (s)	25.008	27.393	🔴 +2.386 (+9.5%)
P50 confirmation (s)	26.222	28.799	🔴 +2.577 (+9.8%)
P95 confirmation (s)	30.503	33.060	🔴 +2.557 (+8.4%)
P99 confirmation (s)	30.724	33.221	🔴 +2.498 (+8.1%)
Tx validation time p50 (s)	9.107	10.066	🔴 +0.959 (+10.5%)
Peak node RSS (MB)	432.90	428.50	≈ -4.40 (-1.0%)
Invalid txs	0.00	0.00	≈ +0.00 (n/a%)

Plateau 1000 UTxO (1 node, 4000 txs)

Metric	master	PR	Δ
End-to-end TPS (tx/s)	246.70	231.40	🔴 -15.30 (-6.2%)
Backlog drain time (s)	16.10	17.20	🔴 +1.10 (+6.8%)
Snapshots per second (/s)	0.56	0.52	-0.04 (-7.1%)
Avg txs per snapshot	444.40	444.40	≈ +0.00 (+0.0%)
Avg. Confirmation Time (s)	9.919	10.399	≈ +0.481 (+4.8%)
P50 confirmation (s)	9.884	10.304	≈ +0.420 (+4.3%)
P95 confirmation (s)	16.118	16.955	🔴 +0.837 (+5.2%)
P99 confirmation (s)	16.119	17.171	🔴 +1.051 (+6.5%)
Tx validation time p50 (s)	5.845	6.294	🔴 +0.449 (+7.7%)
Peak node RSS (MB)	382.90	339.40	-43.50 (-11.4%)
Invalid txs	0.00	0.00	≈ +0.00 (n/a%)

Round-trip latency (3 nodes, closed-loop, 3x250 txs)

Metric	master	PR	Δ
End-to-end TPS (tx/s)	105.33	101.81	≈ -3.52 (-3.3%)
Sustained TPS (tx/s)	106.30	102.79	≈ -3.51 (-3.3%)
Backlog drain time (s)	0.00	0.00	≈ +0.00 (n/a%)
Snapshots per second (/s)	71.20	68.42	≈ -2.78 (-3.9%)
Avg txs per snapshot	1.50	1.50	≈ +0.00 (+0.0%)
Avg. Confirmation Time (s)	0.028	0.029	≈ +0.001 (+3.5%)
P50 confirmation (s)	0.027	0.029	≈ +0.001 (+4.4%)
P95 confirmation (s)	0.038	0.038	≈ -0.000 (-1.0%)
P99 confirmation (s)	0.043	0.043	≈ +0.000 (+0.5%)
Tx validation time p50 (s)	0.007	0.008	🔴 +0.000 (+5.5%)
Peak node RSS (MB)	149.30	149.20	≈ -0.10 (-0.1%)
Invalid txs	0.00	0.00	≈ +0.00 (n/a%)

[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	2026-07-27 14:47:45.60753262 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νHead	f2dd4ade71e19c2310a86215aa78aea06463aca2d8b818af8dc1b8a4	12805
μHead	4abb8dedbcd6a6f03f4fe227300e2713d73b7680d47baa898b60d27a*	4971
νDeposit	c78e8c9205721eb3ef4410f3db9c6169fa6db497c24641d29c20529c	1615
νCRS	09db7ee6cf7a4b358dd5c8a2f19d2c048336ffc5a01ef35a47ca7072	2736

• 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	5476	9.59	3.16	0.49
2	5569	9.82	3.22	0.50
3	5668	10.14	3.31	0.51
5	5861	11.76	3.86	0.53
10	6341	14.08	4.58	0.58
50	10187	35.74	11.36	0.97
100	14983	61.95	19.55	1.45
114	16326	69.84	22.04	1.59

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	2322	21.15	7.52	0.48
2	2450	22.13	8.50	0.50
3	2583	22.62	9.31	0.51
5	2850	25.12	11.45	0.56
10	3501	29.43	16.14	0.66
50	8745	71.14	55.87	1.51
75	12017	97.04	80.62	2.04

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	643	18.46	6.68	0.38
2	774	19.43	7.65	0.40
3	904	20.35	8.61	0.42
5	1167	22.28	10.56	0.46
10	1822	27.05	15.41	0.56
50	7063	68.08	54.89	1.41
75	10338	93.35	79.45	1.93

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
2	800	18.74	12.64	0.43
10	1845	26.55	20.47	0.59
50	7094	67.23	59.94	1.44
74	10234	91.80	83.67	1.95

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	697	21.48	14.90	0.46
2	832	22.64	15.93	0.48
3	964	23.81	16.97	0.51
5	1226	26.05	19.01	0.55
10	1880	31.81	24.17	0.66
50	7126	79.97	65.85	1.58
66	9217	98.57	82.34	1.95

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	5645	23.29	42.87	0.90
10	1	57	5679	25.63	45.39	0.93
10	5	285	5815	35.88	55.71	1.10
10	10	570	5984	49.89	68.99	1.31
10	20	1137	6322	82.42	96.97	1.79
10	20	1140	6324	82.42	96.97	1.79

PartialFanOut transaction costs

Largest chunk of ada-only outputs that can be distributed in one partial fanout step, computed dynamically. The last row is the maximum total UTxO count where at least one output can still be distributed.

Distributed	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
11	570	987	34.91	66.33	0.95
25	1308	1427	68.24	99.40	1.48
30	1308	1427	68.24	99.40	1.48
40	1309	1428	68.24	99.40	1.48
50	1309	1424	68.24	99.40	1.48
100	1309	1428	68.24	99.40	1.48
150	1310	1425	68.24	99.40	1.48
200	1308	1427	68.24	99.40	1.48
200	1310	1429	68.24	99.40	1.48

PartialFanOut transaction costs (with native tokens)

Largest chunk of native-token outputs that can be distributed in one partial fanout step, computed dynamically. The last row is the maximum total UTxO count where at least one output can still be distributed.

Distributed	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
11	1060	1543	42.00	68.86	1.05
25	2520	2786	76.59	99.27	1.61
30	1953	2192	76.56	99.11	1.58
40	2184	2434	76.56	99.16	1.59
50	2331	2585	76.59	99.22	1.60
100	2520	2787	76.59	99.27	1.61
150	2037	2277	76.56	99.12	1.58
200	1974	2215	76.56	99.11	1.58
200	2436	2699	76.59	99.22	1.60

FinalPartialFanOut transaction costs (with native tokens)

Terminal partial fanout step (FanoutProgress → Final) with outputs carrying a native token. Burns all head tokens and proves accumulator exhaustion via BLS proof.

Distributed	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	106	5526	22.10	44.31	0.89
5	600	5935	35.70	55.86	1.10
10	930	6161	53.78	70.57	1.36
10	1150	6380	53.90	70.65	1.38

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 2026-07-27 14:50:01.310668433 UTC

Baseline Scenario

Number of nodes	1
Number of txs	300
Avg. Confirmation Time (ms)	204.5
P99	208.6ms
P95	208.1ms
P50	204.5ms
Tx validation time p50 (ms)	127.9
End-to-end TPS	1406.90 tx/s
Backlog drain time (s)	0.2
Snapshots observed	3
Snapshots per second	14.07 /s
Avg txs per snapshot	100.0
Peak node RSS (MB)	144.9
Number of Invalid txs	0
Fanout outputs	2

Three local nodes

Number of nodes	3
Number of txs	900
Avg. Confirmation Time (ms)	1035.7
P99	1094.3ms
P95	1093.1ms
P50	1067.3ms
Tx validation time p50 (ms)	503.4
End-to-end TPS	815.24 tx/s
Backlog drain time (s)	1.1
Snapshots observed	3
Snapshots per second	2.72 /s
Avg txs per snapshot	300.0
Peak node RSS (MB)	147.6
Number of Invalid txs	0
Fanout outputs	4

Scenario benchmark results

This page collects results from the scenario matrix: every combination of cluster size, UTxO shape, and incremental-ops mode is exercised by CI from the latest master code and reported below.

Numbers are approximate. They come from cloud VMs rather than controlled hardware, so the useful signal is the relative change between cells and between commits, not the absolute throughput.

Generated at 2026-07-27 15:02:21.798363656 UTC

Summary across cells

TPS columns are rates (transactions per second); Wall clock (s) is the measured elapsed time from the first tx submission to the last confirmation. Times are rounded to one decimal.

Scenario	Txs	Wall clock (s)	End-to-end TPS (tx/s)	Sustained TPS (tx/s)	Avg conf (ms)	P95 conf (ms)
Nodes=1, Constant, fire and forget	30	0.0	1245.76	n/a	23.4	23.8
Nodes=1, Constant, wait for tx valid	30	0.1	201.37	201.42	4.9	6.2
Nodes=1, Growing, fire and forget	30	0.0	1086.55	n/a	26.9	27.4
Nodes=1, Growing, wait for tx valid	30	0.2	140.18	142.93	7.1	9.2
Nodes=1, Mixed, fire and forget	30	0.0	1133.34	n/a	25.0	26.2
Nodes=1, Mixed, wait for tx valid	30	0.2	175.13	171.07	5.7	7.7
Nodes=2, Constant, fire and forget	60	0.1	991.96	n/a	59.1	59.9
Nodes=2, Constant, wait for tx valid	60	0.4	134.75	136.80	14.7	20.0
Nodes=2, Growing, fire and forget	60	0.1	735.47	n/a	79.2	81.1
Nodes=2, Growing, wait for tx valid	60	0.7	84.36	84.07	23.3	31.7
Nodes=2, Mixed, fire and forget	60	0.1	988.09	n/a	59.0	59.7
Nodes=2, Mixed, wait for tx valid	60	0.6	92.57	86.11	21.4	29.9
Nodes=3, Constant, fire and forget	90	0.1	704.73	n/a	124.6	126.8
Nodes=3, Constant, wait for tx valid	90	0.9	103.67	104.74	28.3	39.9
Nodes=3, Growing, fire and forget	90	0.2	591.57	n/a	148.8	151.1
Nodes=3, Growing, wait for tx valid	90	1.2	75.15	73.83	39.6	53.6
Nodes=3, Mixed, fire and forget	90	0.1	625.28	n/a	137.9	143.7
Nodes=3, Mixed, wait for tx valid	90	1.1	79.72	75.95	37.4	50.3

Nodes=1, Constant, fire and forget

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	23.4
P99	23.9ms
P95	23.8ms
P50	23.6ms
Tx validation time p50 (ms)	9.1
End-to-end TPS	1245.76 tx/s
Backlog drain time (s)	0.0
Snapshots observed	2
Snapshots per second	83.05 /s
Avg txs per snapshot	15.0
Peak node RSS (MB)	144.1
Number of Invalid txs	0
Fanout outputs	2

Nodes=1, Constant, wait for tx valid

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	4.9
P99	6.9ms
P95	6.2ms
P50	4.7ms
Tx validation time p50 (ms)	1.6
End-to-end TPS	201.37 tx/s
Sustained TPS	201.42 tx/s
Backlog drain time (s)	0.0
Snapshots observed	30
Snapshots per second	201.37 /s
Avg txs per snapshot	1.0
Peak node RSS (MB)	144.1
Number of Invalid txs	0
Fanout outputs	2

Nodes=1, Growing, fire and forget

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	26.9
P99	27.4ms
P95	27.4ms
P50	27.1ms
Tx validation time p50 (ms)	10.6
End-to-end TPS	1086.55 tx/s
Backlog drain time (s)	0.0
Snapshots observed	2
Snapshots per second	72.44 /s
Avg txs per snapshot	15.0
Peak node RSS (MB)	144.5
Number of Invalid txs	0
Fanout outputs	31

Nodes=1, Growing, wait for tx valid

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	7.1
P99	9.7ms
P95	9.2ms
P50	7.1ms
Tx validation time p50 (ms)	1.9
End-to-end TPS	140.18 tx/s
Sustained TPS	142.93 tx/s
Backlog drain time (s)	0.0
Snapshots observed	30
Snapshots per second	140.18 /s
Avg txs per snapshot	1.0
Peak node RSS (MB)	144.8
Number of Invalid txs	0
Fanout outputs	31

Nodes=1, Mixed, fire and forget

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	25.0
P99	26.2ms
P95	26.2ms
P50	25.9ms
Tx validation time p50 (ms)	9.1
End-to-end TPS	1133.34 tx/s
Backlog drain time (s)	0.0
Snapshots observed	2
Snapshots per second	75.56 /s
Avg txs per snapshot	15.0
Peak node RSS (MB)	143.1
Number of Invalid txs	0
Fanout outputs	2

Nodes=1, Mixed, wait for tx valid

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	5.7
P99	9.6ms
P95	7.7ms
P50	5.4ms
Tx validation time p50 (ms)	1.6
End-to-end TPS	175.13 tx/s
Sustained TPS	171.07 tx/s
Backlog drain time (s)	0.0
Snapshots observed	30
Snapshots per second	175.13 /s
Avg txs per snapshot	1.0
Peak node RSS (MB)	143.3
Number of Invalid txs	0
Fanout outputs	2

Nodes=2, Constant, fire and forget

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	59.1
P99	60.0ms
P95	59.9ms
P50	59.5ms
Tx validation time p50 (ms)	23.7
End-to-end TPS	991.96 tx/s
Backlog drain time (s)	0.1
Snapshots observed	2
Snapshots per second	33.07 /s
Avg txs per snapshot	30.0
Peak node RSS (MB)	145.1
Number of Invalid txs	0
Fanout outputs	3

Nodes=2, Constant, wait for tx valid

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	14.7
P99	21.2ms
P95	20.0ms
P50	13.3ms
Tx validation time p50 (ms)	4.0
End-to-end TPS	134.75 tx/s
Sustained TPS	136.80 tx/s
Backlog drain time (s)	0.0
Snapshots observed	60
Snapshots per second	134.75 /s
Avg txs per snapshot	1.0
Peak node RSS (MB)	144.3
Number of Invalid txs	0
Fanout outputs	3

Nodes=2, Growing, fire and forget

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	79.2
P99	81.2ms
P95	81.1ms
P50	79.6ms
Tx validation time p50 (ms)	27.9
End-to-end TPS	735.47 tx/s
Backlog drain time (s)	0.1
Snapshots observed	2
Snapshots per second	24.52 /s
Avg txs per snapshot	30.0
Peak node RSS (MB)	145.2
Number of Invalid txs	0
Fanout outputs	62

Nodes=2, Growing, wait for tx valid

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	23.3
P99	33.1ms
P95	31.7ms
P50	22.9ms
Tx validation time p50 (ms)	7.2
End-to-end TPS	84.36 tx/s
Sustained TPS	84.07 tx/s
Backlog drain time (s)	0.0
Snapshots observed	60
Snapshots per second	84.36 /s
Avg txs per snapshot	1.0
Peak node RSS (MB)	147.5
Number of Invalid txs	0
Fanout outputs	62

Nodes=2, Mixed, fire and forget

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	59.0
P99	59.7ms
P95	59.7ms
P50	59.3ms
Tx validation time p50 (ms)	19.9
End-to-end TPS	988.09 tx/s
Backlog drain time (s)	0.1
Snapshots observed	2
Snapshots per second	32.94 /s
Avg txs per snapshot	30.0
Peak node RSS (MB)	144.4
Number of Invalid txs	0
Fanout outputs	3

Nodes=2, Mixed, wait for tx valid

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	21.4
P99	31.3ms
P95	29.9ms
P50	21.4ms
Tx validation time p50 (ms)	5.9
End-to-end TPS	92.57 tx/s
Sustained TPS	86.11 tx/s
Backlog drain time (s)	0.0
Snapshots observed	60
Snapshots per second	92.57 /s
Avg txs per snapshot	1.0
Peak node RSS (MB)	145.9
Number of Invalid txs	0
Fanout outputs	3

Nodes=3, Constant, fire and forget

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	124.6
P99	126.9ms
P95	126.8ms
P50	124.3ms
Tx validation time p50 (ms)	44.0
End-to-end TPS	704.73 tx/s
Backlog drain time (s)	0.1
Snapshots observed	2
Snapshots per second	15.66 /s
Avg txs per snapshot	45.0
Peak node RSS (MB)	146.3
Number of Invalid txs	0
Fanout outputs	4

Nodes=3, Constant, wait for tx valid

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	28.3
P99	50.0ms
P95	39.9ms
P50	27.0ms
Tx validation time p50 (ms)	7.1
End-to-end TPS	103.67 tx/s
Sustained TPS	104.74 tx/s
Backlog drain time (s)	0.0
Snapshots observed	62
Snapshots per second	71.42 /s
Avg txs per snapshot	1.5
Peak node RSS (MB)	145.5
Number of Invalid txs	0
Fanout outputs	4

Nodes=3, Growing, fire and forget

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	148.8
P99	151.2ms
P95	151.1ms
P50	149.0ms
Tx validation time p50 (ms)	43.2
End-to-end TPS	591.57 tx/s
Backlog drain time (s)	0.1
Snapshots observed	2
Snapshots per second	13.15 /s
Avg txs per snapshot	45.0
Peak node RSS (MB)	145.1
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Growing, wait for tx valid

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	39.6
P99	66.8ms
P95	53.6ms
P50	38.1ms
Tx validation time p50 (ms)	11.0
End-to-end TPS	75.15 tx/s
Sustained TPS	73.83 tx/s
Backlog drain time (s)	0.0
Snapshots observed	62
Snapshots per second	51.77 /s
Avg txs per snapshot	1.5
Peak node RSS (MB)	148.1
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Mixed, fire and forget

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	137.9
P99	143.7ms
P95	143.7ms
P50	137.3ms
Tx validation time p50 (ms)	49.1
End-to-end TPS	625.28 tx/s
Backlog drain time (s)	0.1
Snapshots observed	2
Snapshots per second	13.90 /s
Avg txs per snapshot	45.0
Peak node RSS (MB)	145.5
Number of Invalid txs	0
Fanout outputs	4

Nodes=3, Mixed, wait for tx valid

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	37.4
P99	58.2ms
P95	50.3ms
P50	36.8ms
Tx validation time p50 (ms)	10.2
End-to-end TPS	79.72 tx/s
Sustained TPS	75.95 tx/s
Backlog drain time (s)	0.0
Snapshots observed	61
Snapshots per second	54.03 /s
Avg txs per snapshot	1.5
Peak node RSS (MB)	147.1
Number of Invalid txs	0
Fanout outputs	4