MIP Ref Impl: Increase zkApp account update limit

src/app/zkapp_limits/zkapp_limits.ml

@@ -2,31 +2,35 @@
 open Core_kernel
 
 let main () =
-  let genesis_constants = Genesis_constants.Compiled.genesis_constants in
-  let cost_limit = genesis_constants.zkapp_transaction_cost_limit in
-  let max_event_elements = genesis_constants.max_event_elements in
-  let max_action_elements = genesis_constants.max_action_elements in
-  let values = List.init 20 ~f:Fn.id in
+  let Genesis_constants.
+        { max_event_elements
+        ; max_action_elements
+        ; max_zkapp_segment_per_transaction
+        ; _
+        } =
+    Genesis_constants.Compiled.genesis_constants
+  in
+  let values = List.init (1 + max_zkapp_segment_per_transaction) ~f:Fn.id in
   printf "max field elements for events per transaction: %d\n"
     max_event_elements ;
   printf "max field elements for actions per transaction: %d\n"
     max_action_elements ;
   printf "All possible zkApp account update combinations:\n" ;
-  List.iter values ~f:(fun proofs ->
+  List.iter values ~f:(fun proof_segments ->
       List.iter values ~f:(fun signed_single_segments ->
           List.iter values ~f:(fun signed_pair_segments ->
               let cost =
-                Mina_base.Zkapp_command.zkapp_cost ~proof_segments:proofs
+                Mina_base.Zkapp_command.zkapp_cost ~proof_segments
                   ~signed_single_segments ~signed_pair_segments
-                  ~genesis_constants ()
               in
-              if Float.(cost <. cost_limit) then
+              if cost <= max_zkapp_segment_per_transaction then
                 printf
                   "Proofs updates=%d  Signed/None updates=%d  Pairs of \
-                   Signed/None updates=%d: Total account updates: %d Cost: %f \n\
+                   Signed/None updates=%d: Total account updates: %d Cost: %d \n\
                    %!"
-                  proofs signed_single_segments signed_pair_segments
-                  (proofs + signed_single_segments + (signed_pair_segments * 2))
+                  proof_segments signed_single_segments signed_pair_segments
+                  ( proof_segments + signed_single_segments
+                  + (signed_pair_segments * 2) )
                   cost ) ) )
 
 let () = main ()

src/lib/genesis_constants/genesis_constants.ml

@@ -215,10 +215,11 @@ module T = struct
     { protocol : Protocol.Stable.Latest.t
     ; txpool_max_size : int
     ; num_accounts : int option
-    ; zkapp_proof_update_cost : float
-    ; zkapp_signed_single_update_cost : float
-    ; zkapp_signed_pair_update_cost : float
-    ; zkapp_transaction_cost_limit : float
+    ; max_zkapp_segment_per_transaction : int
+          (** The maximum number of segments allowed per zkapp command. A
+              segment is either: a proof, a signed single update, or a signed
+              pair update. Transactions with a number of segments equal to this
+              limit are valid. *)
     ; max_event_elements : int
     ; max_action_elements : int
     ; zkapp_cmd_limit_hardcap : int
@@ -425,11 +426,8 @@ module Make (Node_config : Node_config_intf.S) : S = struct
         }
     ; txpool_max_size = pool_max_size
     ; num_accounts = None
-    ; zkapp_proof_update_cost = Node_config.zkapp_proof_update_cost
-    ; zkapp_signed_single_update_cost =
-        Node_config.zkapp_signed_single_update_cost
-    ; zkapp_signed_pair_update_cost = Node_config.zkapp_signed_pair_update_cost
-    ; zkapp_transaction_cost_limit = Node_config.zkapp_transaction_cost_limit
+    ; max_zkapp_segment_per_transaction =
+        Node_config.max_zkapp_segment_per_transaction
     ; max_event_elements = Node_config.max_event_elements
     ; max_action_elements = Node_config.max_action_elements
     ; zkapp_cmd_limit_hardcap = Node_config.zkapp_cmd_limit_hardcap

src/lib/genesis_ledger_helper/lib/genesis_ledger_helper_lib.ml

@@ -563,18 +563,9 @@ let make_genesis_constants ~logger ~(default : Genesis_constants.t)
   ; txpool_max_size =
       Option.value ~default:default.txpool_max_size
         (config.daemon >>= fun cfg -> cfg.txpool_max_size)
-  ; zkapp_proof_update_cost =
-      Option.value ~default:default.zkapp_proof_update_cost
-        (config.daemon >>= fun cfg -> cfg.zkapp_proof_update_cost)
-  ; zkapp_signed_single_update_cost =
-      Option.value ~default:default.zkapp_signed_single_update_cost
-        (config.daemon >>= fun cfg -> cfg.zkapp_signed_single_update_cost)
-  ; zkapp_signed_pair_update_cost =
-      Option.value ~default:default.zkapp_signed_pair_update_cost
-        (config.daemon >>= fun cfg -> cfg.zkapp_signed_pair_update_cost)
-  ; zkapp_transaction_cost_limit =
-      Option.value ~default:default.zkapp_transaction_cost_limit
-        (config.daemon >>= fun cfg -> cfg.zkapp_transaction_cost_limit)
+  ; max_zkapp_segment_per_transaction =
+      Option.value ~default:default.max_zkapp_segment_per_transaction
+        (config.daemon >>= fun cfg -> cfg.max_zkapp_segment_per_transaction)
   ; max_event_elements =
       Option.value ~default:default.max_event_elements
         (config.daemon >>= fun cfg -> cfg.max_event_elements)

src/lib/mina_base/zkapp_command.ml

@@ -1309,16 +1309,33 @@ module Update_group = Make_update_group (struct
         failwith "zkapp_segment_of_controls: Unsupported combination"
 end)
 
-let zkapp_cost ~proof_segments ~signed_single_segments ~signed_pair_segments
-    ~(genesis_constants : Genesis_constants.t) () =
-  (*10.26*np + 10.08*n2 + 9.14*n1 < 69.45*)
-  let proof_cost = genesis_constants.zkapp_proof_update_cost in
-  let signed_pair_cost = genesis_constants.zkapp_signed_pair_update_cost in
-  let signed_single_cost = genesis_constants.zkapp_signed_single_update_cost in
-  Float.(
-    (proof_cost * of_int proof_segments)
-    + (signed_pair_cost * of_int signed_pair_segments)
-    + (signed_single_cost * of_int signed_single_segments))
+(** [zkapp_cost ~proof_segments ~signed_single_segments ~signed_pair_segments]
+    returns the cost of a zkapp command having such constitution.
+
+    The cost of a zkapp command is defined as the number of segments it have in
+    the base layer.
+
+    This is because SNARK Coordinator schedules single base proof/merge to each
+    SNARK worker. These proofs form a B-ary tree, where B is Pickles' branching
+    factor, i.e. the number of proofs Pickles could be merged at once. Under
+    current configuration, B is 2.
+
+    The latency before us getting a final proof would be the latency from root
+    to any leaf node. Given we have sufficient workers available, possible proof
+    trees would be more or less a balanced binary tree, so with n segments, the
+    latency would of Theta(log_B n), assuming all kind proofs requires roughly
+    same time to proof.
+
+    to ensure the latency of receving final proof to be smaller than some cap,
+    we could equally just restrict number of leave segments. For example, If we
+    want the tree to have at most [L] layers, we just ensure the cost for any
+    zkapp_command to be at most [B^L].
+
+    WARN: this is only relevant after we merged SNARK worker rework PRs, please
+    remove this warning if we've already done so.
+*)
+let zkapp_cost ~proof_segments ~signed_single_segments ~signed_pair_segments =
+  proof_segments + signed_single_segments + signed_pair_segments
 
 (* Zkapp_command transactions are filtered using this predicate
    - when adding to the transaction pool
@@ -1361,14 +1378,17 @@ let valid_size (type aux) ~(genesis_constants : Genesis_constants.t)
         | Signed_pair ->
             (proof_segments, signed_singles, signed_pairs + 1) )
   in
-  let cost_limit = genesis_constants.zkapp_transaction_cost_limit in
-  let max_event_elements = genesis_constants.max_event_elements in
-  let max_action_elements = genesis_constants.max_action_elements in
+  let Genesis_constants.
+        { max_event_elements
+        ; max_action_elements
+        ; max_zkapp_segment_per_transaction
+        ; _
+        } =
+    genesis_constants
+  in
   let zkapp_cost_within_limit =
-    Float.(
-      zkapp_cost ~proof_segments ~signed_single_segments ~signed_pair_segments
-        ~genesis_constants ()
-      < cost_limit)
+    zkapp_cost ~proof_segments ~signed_single_segments ~signed_pair_segments
+    <= max_zkapp_segment_per_transaction
   in
   let valid_event_elements = num_event_elements <= max_event_elements in
   let valid_action_elements = num_action_elements <= max_action_elements in

src/lib/mina_compile_config/mina_compile_config.ml

@@ -20,10 +20,7 @@ module Inputs = struct
     ; rpc_handshake_timeout_sec : float
     ; rpc_heartbeat_timeout_sec : float
     ; rpc_heartbeat_send_every_sec : float
-    ; zkapp_proof_update_cost : float
-    ; zkapp_signed_pair_update_cost : float
-    ; zkapp_signed_single_update_cost : float
-    ; zkapp_transaction_cost_limit : float
+    ; max_zkapp_segment_per_transaction : int
     ; max_event_elements : int
     ; max_action_elements : int
     ; zkapp_cmd_limit_hardcap : int
@@ -47,10 +44,7 @@ type t =
   ; rpc_handshake_timeout : Time.Span.t
   ; rpc_heartbeat_timeout : Time.Span.t
   ; rpc_heartbeat_send_every : Time.Span.t
-  ; zkapp_proof_update_cost : float
-  ; zkapp_signed_pair_update_cost : float
-  ; zkapp_signed_single_update_cost : float
-  ; zkapp_transaction_cost_limit : float
+  ; max_zkapp_segment_per_transaction : int
   ; max_event_elements : int
   ; max_action_elements : int
   ; zkapp_cmd_limit_hardcap : int
@@ -80,10 +74,7 @@ let make (inputs : Inputs.t) =
   ; rpc_heartbeat_timeout = Time.Span.of_sec inputs.rpc_heartbeat_timeout_sec
   ; rpc_heartbeat_send_every =
       Time.Span.of_sec inputs.rpc_heartbeat_send_every_sec
-  ; zkapp_proof_update_cost = inputs.zkapp_proof_update_cost
-  ; zkapp_signed_pair_update_cost = inputs.zkapp_signed_pair_update_cost
-  ; zkapp_signed_single_update_cost = inputs.zkapp_signed_single_update_cost
-  ; zkapp_transaction_cost_limit = inputs.zkapp_transaction_cost_limit
+  ; max_zkapp_segment_per_transaction = inputs.max_zkapp_segment_per_transaction
   ; max_event_elements = inputs.max_event_elements
   ; max_action_elements = inputs.max_action_elements
   ; network_id = inputs.network_id
@@ -115,11 +106,8 @@ let to_yojson t =
       , `Float (Time.Span.to_sec t.rpc_heartbeat_timeout) )
     ; ( "rpc_heartbeat_send_every"
       , `Float (Time.Span.to_sec t.rpc_heartbeat_send_every) )
-    ; ("zkapp_proof_update_cost", `Float t.zkapp_proof_update_cost)
-    ; ("zkapp_signed_pair_update_cost", `Float t.zkapp_signed_pair_update_cost)
-    ; ( "zkapp_signed_single_update_cost"
-      , `Float t.zkapp_signed_single_update_cost )
-    ; ("zkapp_transaction_cost_limit", `Float t.zkapp_transaction_cost_limit)
+    ; ( "max_zkapp_segment_per_transaction"
+      , `Int t.max_zkapp_segment_per_transaction )
     ; ("max_event_elements", `Int t.max_event_elements)
     ; ("max_action_elements", `Int t.max_action_elements)
     ; ("network_id", `String t.network_id)
@@ -147,12 +135,8 @@ module Compiled = struct
       ; rpc_handshake_timeout_sec = Node_config.rpc_handshake_timeout_sec
       ; rpc_heartbeat_timeout_sec = Node_config.rpc_heartbeat_timeout_sec
       ; rpc_heartbeat_send_every_sec = Node_config.rpc_heartbeat_send_every_sec
-      ; zkapp_proof_update_cost = Node_config.zkapp_proof_update_cost
-      ; zkapp_signed_pair_update_cost =
-          Node_config.zkapp_signed_pair_update_cost
-      ; zkapp_signed_single_update_cost =
-          Node_config.zkapp_signed_single_update_cost
-      ; zkapp_transaction_cost_limit = Node_config.zkapp_transaction_cost_limit
+      ; max_zkapp_segment_per_transaction =
+          Node_config.max_zkapp_segment_per_transaction
       ; max_event_elements = Node_config.max_event_elements
       ; max_action_elements = Node_config.max_action_elements
       ; network_id = Node_config.network
@@ -188,14 +172,8 @@ module For_unit_tests = struct
           Node_config_for_unit_tests.rpc_heartbeat_timeout_sec
       ; rpc_heartbeat_send_every_sec =
           Node_config_for_unit_tests.rpc_heartbeat_send_every_sec
-      ; zkapp_proof_update_cost =
-          Node_config_for_unit_tests.zkapp_proof_update_cost
-      ; zkapp_signed_pair_update_cost =
-          Node_config_for_unit_tests.zkapp_signed_pair_update_cost
-      ; zkapp_signed_single_update_cost =
-          Node_config_for_unit_tests.zkapp_signed_single_update_cost
-      ; zkapp_transaction_cost_limit =
-          Node_config_for_unit_tests.zkapp_transaction_cost_limit
+      ; max_zkapp_segment_per_transaction =
+          Node_config_for_unit_tests.max_zkapp_segment_per_transaction
       ; max_event_elements = Node_config_for_unit_tests.max_event_elements
       ; max_action_elements = Node_config_for_unit_tests.max_action_elements
       ; network_id = Node_config_for_unit_tests.network

src/lib/node_config/intf/node_config_intf.mli

@@ -8,13 +8,7 @@ end
 
 (* It's stupid that this exists. TODO: Remove and make configurable. *)
 module type Unconfigurable_constants = sig
-  val zkapp_proof_update_cost : float
-
-  val zkapp_signed_pair_update_cost : float
-
-  val zkapp_signed_single_update_cost : float
-
-  val zkapp_transaction_cost_limit : float
+  val max_zkapp_segment_per_transaction : int
 
   val max_event_elements : int
 

src/lib/node_config/unconfigurable_constants/node_config_unconfigurable_constants.ml

@@ -1,25 +1,6 @@
 (* FIXME: These should be configurable. *)
 
-(** limits on Zkapp_command.t size
-    10.26*np + 10.08*n2 + 9.14*n1 < 69.45
-    where np: number of single proof updates
-    n2: number of pairs of signed/no-auth update
-    n1: number of single signed/no-auth update
-    and their coefficients representing the cost
-  The formula was generated based on benchmarking data conducted on bare
-  metal i9 processor with room to include lower spec.
-  69.45 was the total time for a combination of updates that was considered
-  acceptable.
-  The method used to estimate the cost was linear least squares.
-*)
-
-let zkapp_proof_update_cost = 10.26
-
-let zkapp_signed_pair_update_cost = 10.08
-
-let zkapp_signed_single_update_cost = 9.14
-
-let zkapp_transaction_cost_limit = 69.45
+let max_zkapp_segment_per_transaction = 16
 
 let max_event_elements = 100
 

src/lib/runtime_config/runtime_config.ml

@@ -464,10 +464,7 @@ module Json_layout = struct
     type t =
       { txpool_max_size : int option [@default None]
       ; peer_list_url : string option [@default None]
-      ; zkapp_proof_update_cost : float option [@default None]
-      ; zkapp_signed_single_update_cost : float option [@default None]
-      ; zkapp_signed_pair_update_cost : float option [@default None]
-      ; zkapp_transaction_cost_limit : float option [@default None]
+      ; max_zkapp_segment_per_transaction : int option [@default None]
       ; max_event_elements : int option [@default None]
       ; max_action_elements : int option [@default None]
       ; zkapp_cmd_limit_hardcap : int option [@default None]
@@ -1271,10 +1268,7 @@ module Daemon = struct
   type t = Json_layout.Daemon.t =
     { txpool_max_size : int option
     ; peer_list_url : string option
-    ; zkapp_proof_update_cost : float option [@default None]
-    ; zkapp_signed_single_update_cost : float option [@default None]
-    ; zkapp_signed_pair_update_cost : float option [@default None]
-    ; zkapp_transaction_cost_limit : float option [@default None]
+    ; max_zkapp_segment_per_transaction : int option [@default None]
     ; max_event_elements : int option [@default None]
     ; max_action_elements : int option [@default None]
     ; zkapp_cmd_limit_hardcap : int option [@default None]
@@ -1303,18 +1297,9 @@ module Daemon = struct
     { txpool_max_size =
         opt_fallthrough ~default:t1.txpool_max_size t2.txpool_max_size
     ; peer_list_url = opt_fallthrough ~default:t1.peer_list_url t2.peer_list_url
-    ; zkapp_proof_update_cost =
-        opt_fallthrough ~default:t1.zkapp_proof_update_cost
-          t2.zkapp_proof_update_cost
-    ; zkapp_signed_single_update_cost =
-        opt_fallthrough ~default:t1.zkapp_signed_single_update_cost
-          t2.zkapp_signed_single_update_cost
-    ; zkapp_signed_pair_update_cost =
-        opt_fallthrough ~default:t1.zkapp_signed_pair_update_cost
-          t2.zkapp_signed_pair_update_cost
-    ; zkapp_transaction_cost_limit =
-        opt_fallthrough ~default:t1.zkapp_transaction_cost_limit
-          t2.zkapp_transaction_cost_limit
+    ; max_zkapp_segment_per_transaction =
+        opt_fallthrough ~default:t1.max_zkapp_segment_per_transaction
+          t2.max_zkapp_segment_per_transaction
     ; max_event_elements =
         opt_fallthrough ~default:t1.max_event_elements t2.max_event_elements
     ; max_action_elements =
@@ -1343,10 +1328,7 @@ module Daemon = struct
   let gen =
     let open Quickcheck.Generator.Let_syntax in
     let%bind txpool_max_size = Int.gen_incl 0 1000 in
-    let%bind zkapp_proof_update_cost = Float.gen_incl 0.0 100.0 in
-    let%bind zkapp_signed_single_update_cost = Float.gen_incl 0.0 100.0 in
-    let%bind zkapp_signed_pair_update_cost = Float.gen_incl 0.0 100.0 in
-    let%bind zkapp_transaction_cost_limit = Float.gen_incl 0.0 100.0 in
+    let%bind max_zkapp_segment_per_transaction = Int.gen_incl 0 50 in
     let%bind max_event_elements = Int.gen_incl 0 100 in
     let%bind zkapp_cmd_limit_hardcap = Int.gen_incl 0 1000 in
     let%bind minimum_user_command_fee =
@@ -1355,10 +1337,7 @@ module Daemon = struct
     let%map max_action_elements = Int.gen_incl 0 1000 in
     { txpool_max_size = Some txpool_max_size
     ; peer_list_url = None
-    ; zkapp_proof_update_cost = Some zkapp_proof_update_cost
-    ; zkapp_signed_single_update_cost = Some zkapp_signed_single_update_cost
-    ; zkapp_signed_pair_update_cost = Some zkapp_signed_pair_update_cost
-    ; zkapp_transaction_cost_limit = Some zkapp_transaction_cost_limit
+    ; max_zkapp_segment_per_transaction = Some max_zkapp_segment_per_transaction
     ; max_event_elements = Some max_event_elements
     ; max_action_elements = Some max_action_elements
     ; zkapp_cmd_limit_hardcap = Some zkapp_cmd_limit_hardcap

src/lib/testing/integration_test_lib/runtime_config_builder.ml

@@ -14,10 +14,7 @@ let create ~(test_config : Test_config.t) ~(genesis_ledger : Genesis_ledger.t) =
       Some
         { txpool_max_size = Some test_config.txpool_max_size
         ; peer_list_url = None
-        ; zkapp_proof_update_cost = None
-        ; zkapp_signed_single_update_cost = None
-        ; zkapp_signed_pair_update_cost = None
-        ; zkapp_transaction_cost_limit = None
+        ; max_zkapp_segment_per_transaction = None
         ; max_event_elements = None
         ; max_action_elements = None
         ; zkapp_cmd_limit_hardcap = None