The hydra node can publish hydra scripts via blockfrost using --blockfrost

[v0d1ch]

• This is another chunk of work related to building and posting txs responsible for creating Hydra script outputs using Blockfrost

• Unfortunately I had to use a fork of the official library since I could not find a workaround for overlapping json instance https://github.com/blockfrost/blockfrost-haskell/blob/1a5360a51a1b61a14ffac4827f30c1ed525dedf3/blockfrost-api/src/Blockfrost/Types/Cardano/Pools.hs#L170

• Work here contains initial efforts by @ffakenz Refactor PublishOptions to support Blockfrost options + building and submitting relevant txs and code to connect publishing of scripts in this way.

• One could test it like so:

✦ ➜  nix run .#hydra-node -- publish-scripts \
    --blockfrost "/home/v0d1ch/code/hydra/blockfrost.txt" \
    --cardano-signing-key hydra-cluster/config/credentials/alice.sk
evaluation warning: Explicitly set the ABI version of 'webkitgtk'
f5857bddd32b73d14fb6619f0f841050dc5a32ce80ba6644a9b71b3f5a15598d,2bab813d9de51311cb0f3797cc82d5a04126724d16d145768faf4a613341099c,5220d48789de0b105fb94788f5278628c04fcb1bdbbe02260a80d8fe064ada7c

---

• 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]

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	2025-03-31 12:50:51.69778145 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	6093	10.98	3.42	0.53
2	6292	13.47	4.19	0.57
3	6496	15.50	4.80	0.60
5	6895	20.19	6.25	0.66
10	7907	30.97	9.53	0.82
40	13935	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	559	2.44	1.16	0.20
2	741	3.38	1.73	0.22
3	919	4.36	2.33	0.24
5	1279	6.41	3.60	0.28
10	2180	12.13	7.25	0.40
54	10074	98.61	68.52	1.88

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	525	26.44	7.58	0.44
2	114	636	35.86	10.21	0.54
3	170	747	45.83	12.98	0.65
4	228	858	50.75	14.59	0.70
5	282	969	65.05	18.37	0.85
6	341	1081	78.87	22.07	0.99
7	393	1192	78.47	22.41	1.00
8	450	1307	85.04	24.47	1.07
9	504	1414	97.18	27.79	1.20

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	1818	25.03	8.22	0.49
2	1886	25.98	9.08	0.51
3	2149	29.83	11.08	0.57
5	2279	30.48	12.50	0.59
10	3161	44.25	20.39	0.79
38	7231	97.74	56.20	1.66

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	601	23.71	7.54	0.42
2	696	23.72	8.18	0.43
3	958	28.33	10.14	0.49
5	1150	29.79	11.85	0.53
10	2023	41.95	18.55	0.71
40	6393	98.84	54.24	1.62

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	658	30.95	9.68	0.50
2	790	32.84	10.92	0.53
3	925	34.67	12.15	0.56
5	1267	37.10	14.40	0.61
10	2244	50.11	22.32	0.81
35	5824	98.78	54.49	1.60

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	704	35.95	11.01	0.55
2	888	38.77	12.63	0.59
3	954	40.28	13.63	0.62
5	1216	44.67	16.27	0.68
10	2121	58.96	24.38	0.90
26	4469	97.36	47.01	1.47

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	5985	28.29	9.32	0.71
2	6145	38.57	12.75	0.82
3	6334	49.12	16.25	0.94
4	6322	56.26	18.54	1.02
5	6516	66.45	21.94	1.13
6	6581	72.21	23.79	1.19
7	6792	80.44	26.57	1.29
8	6902	88.34	29.19	1.38

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	5	283	6259	30.97	10.82	0.75
10	10	569	6431	41.88	15.03	0.88
10	20	1137	6769	62.72	23.14	1.12
10	30	1707	7111	84.22	31.47	1.37
10	37	2107	7350	97.56	36.72	1.53

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 2025-03-31 12:54:13.610174901 UTC

Baseline Scenario

Number of nodes	1
Number of txs	300
Avg. Confirmation Time (ms)	4.676077710
P99	7.373029939999992ms
P95	5.5698067ms
P50	4.391006000000001ms
Number of Invalid txs	0

Memory data

Time	Used	Free
2025-03-31 12:52:57.400434775 UTC	867M	6564M
2025-03-31 12:53:02.400420049 UTC	1005M	6367M
2025-03-31 12:53:07.400370056 UTC	1005M	6366M
2025-03-31 12:53:12.4003507 UTC	1017M	6353M
2025-03-31 12:53:17.400363058 UTC	1019M	6351M
2025-03-31 12:53:22.40033081 UTC	1019M	6351M

Three local nodes

Number of nodes	3
Number of txs	900
Avg. Confirmation Time (ms)	32.738731897
P99	70.66948986000001ms
P95	55.69975874999999ms
P50	29.281999ms
Number of Invalid txs	0

Memory data

Time	Used	Free
2025-03-31 12:53:35.602454826 UTC	933M	6447M
2025-03-31 12:53:40.602693724 UTC	1199M	6180M
2025-03-31 12:53:45.603705754 UTC	1249M	6073M
2025-03-31 12:53:50.602613631 UTC	1259M	6016M
2025-03-31 12:53:55.602588537 UTC	1260M	6007M
2025-03-31 12:54:00.60249345 UTC	1265M	6001M
2025-03-31 12:54:05.602669264 UTC	1267M	5999M
2025-03-31 12:54:10.602575873 UTC	1267M	5998M

[ch1bo]

Unfortunately I had to use a fork of the official library since I could not find a workaround for overlapping json instance https://github.com/blockfrost/blockfrost-haskell/blob/1a5360a51a1b61a14ffac4827f30c1ed525dedf3/blockfrost-api/src/Blockfrost/Types/Cardano/Pools.hs#L170

@v0d1ch What issue concretely did you encounter with the instance overlap? i.e. which of our instances would overlap with this one?

[v0d1ch]

@ch1bo json instance for Message type https://github.com/cardano-scaling/hydra/blob/master/hydra-node/src/Hydra/Network/Message.hs#L48 specifically incrementUTxO field

[ch1bo]

@ch1bo json instance for Message type https://github.com/cardano-scaling/hydra/blob/master/hydra-node/src/Hydra/Network/Message.hs#L48 specifically incrementUTxO field

Okay. This works for me:

diff --git a/hydra-node/src/Hydra/Network/Message.hs b/hydra-node/src/Hydra/Network/Message.hs
index b7ea84b91d..14c4441a70 100644
--- a/hydra-node/src/Hydra/Network/Message.hs
+++ b/hydra-node/src/Hydra/Network/Message.hs
@@ -45,8 +45,8 @@ data Message tx
 
 deriving stock instance IsTx tx => Eq (Message tx)
 deriving stock instance IsTx tx => Show (Message tx)
-deriving anyclass instance IsTx tx => ToJSON (Message tx)
-deriving anyclass instance IsTx tx => FromJSON (Message tx)
+deriving anyclass instance {-# OVERLAPPABLE #-} IsTx tx => ToJSON (Message tx)
+deriving anyclass instance {-# OVERLAPPABLE #-} IsTx tx => FromJSON (Message tx)
 
 instance ArbitraryIsTx tx => Arbitrary (Message tx) where
   arbitrary = genericArbitrary

We should add an explanation though and ideally we would have more fine-grained constraints in the future as that would make it more clear that Maybe (UTxOType tx) is the issue here (it depends on how UTxoType tx is instantiated and as soon as one concrete Maybe Type is in scope this can overlap).

[v0d1ch]

Hmm... I already tried using OVERLAPPABLE but it didn't do the trick. I'll report back when I get to it.

[v0d1ch]

Yup, this is what I used to get too:

src/Hydra/Network/Message.hs:48:1: error: [GHC-43085]
    • Overlapping instances for ToJSON (Maybe (UTxOType tx))
        arising from a use of ‘aeson-2.2.3.0:Data.Aeson.Types.ToJSON.$dmtoJSON’
      Matching instance:
        instance ToJSON a => ToJSON (Maybe a)
          -- Defined in ‘aeson-2.2.3.0:Data.Aeson.Types.ToJSON’
        ...plus one instance involving out-of-scope types
          Potentially matching instance:
            instance [overlap ok] ToJSON
                                    (Maybe
                                       blockfrost-api-0.12.1.0:Blockfrost.Types.Cardano.Pools.PoolMetadata)
      (The choice depends on the instantiation of ‘tx’
       and the result of evaluating ‘UTxOType’
       To pick the first instance above, use IncoherentInstances
       when compiling the other instance declarations)
    • In the expression:
        aeson-2.2.3.0:Data.Aeson.Types.ToJSON.$dmtoJSON @(Message tx)
      In an equation for ‘toJSON’:
          toJSON
            = aeson-2.2.3.0:Data.Aeson.Types.ToJSON.$dmtoJSON @(Message tx)
      When typechecking the code for ‘toJSON’
        in a derived instance for ‘ToJSON (Message tx)’:
        To see the code I am typechecking, use -ddump-deriv
      In the instance declaration for ‘ToJSON (Message tx)’
   |
48 | deriving anyclass instance {-# OVERLAPPABLE #-} IsTx tx => ToJSON (Message tx)
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

src/Hydra/Network/Message.hs:49:1: error: [GHC-43085]
    • Overlapping instances for FromJSON (Maybe (UTxOType tx))
        arising from a use of ‘aeson-2.2.3.0:Data.Aeson.Types.FromJSON.$dmparseJSON’
      Matching instance:
        instance FromJSON a => FromJSON (Maybe a)
          -- Defined in ‘aeson-2.2.3.0:Data.Aeson.Types.FromJSON’
        ...plus one instance involving out-of-scope types
          Potentially matching instance:
            instance [overlap ok] FromJSON
                                    (Maybe
                                       blockfrost-api-0.12.1.0:Blockfrost.Types.Cardano.Pools.PoolMetadata)
      (The choice depends on the instantiation of ‘tx’
       and the result of evaluating ‘UTxOType’
       To pick the first instance above, use IncoherentInstances
       when compiling the other instance declarations)
    • In the expression:
        aeson-2.2.3.0:Data.Aeson.Types.FromJSON.$dmparseJSON @(Message tx)
      In an equation for ‘parseJSON’:
          parseJSON
            = aeson-2.2.3.0:Data.Aeson.Types.FromJSON.$dmparseJSON
                @(Message tx)
      When typechecking the code for ‘parseJSON’
        in a derived instance for ‘FromJSON (Message tx)’:
        To see the code I am typechecking, use -ddump-deriv
      In the instance declaration for ‘FromJSON (Message tx)’
   |
49 | deriving anyclass instance {-# OVERLAPPABLE #-} IsTx tx => FromJSON (Message tx)