Mempool limits

data/simulation/config.d.ts

@@ -63,6 +63,10 @@ export interface Config {
    * If true, transactions will be removed from the Leios mempool if they conflict with in-flight IBs.
    */
   "leios-mempool-aggressive-pruning": boolean;
+  /**
+   * The maximum size of a mempool, in bytes
+   */
+  "leios-mempool-size-bytes"?: bigint | null;
   /**
    * Praos blockchain quality parameter.
    * This is η from the Leios paper.

data/simulation/config.default.yaml

@@ -32,6 +32,7 @@ leios-header-diffusion-time-ms: 1000.0
 leios-ib-generation-time-ms: 130.0
 leios-mempool-sampling-strategy: ordered-by-id
 leios-mempool-aggressive-pruning: false
+leios-mempool-size-bytes: null
 # TODO: revise default
 praos-chain-quality: 40
 praos-fallback-enabled: true

data/simulation/config.schema.json

@@ -383,6 +383,12 @@
       "$ref": "#/definitions/MempoolSamplingStrategy",
       "description": "The strategy to use when selecting TXs from the Leios mempool."
     },
+    "leios-mempool-size-bytes": {
+      "additionalProperties": false,
+      "description": "The maximum size of a mempool, in bytes",
+      "properties": {},
+      "type": "number"
+    },
     "leios-stage-active-voting-slots": {
       "additionalProperties": false,
       "properties": {},

sim-rs/CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## v1.4.0
+
+### Linear Leios
+
+- Add bounded mempools. Configure them with by setting `leios-mempool-size-bytes`. Incoming transactions which don't fit in the mempool will be queued for inclusion in the mempool when there is space. Transactions referenced by an EB which are not yet in the mempool will still be forwarded to peers.
+
+### Other
+
+- Fix warnings from new rust version
+
 ## v1.3.1
 
 ### Linear Leios

sim-rs/implementations/LINEAR_LEIOS.md

@@ -50,6 +50,12 @@ When a node creates an RB, it will follow these steps in order:
 
 When a node receives an RB body, it immediately removes all referenced/conflicting transactions from its mempool. If the RB has an EB certificate, it also removes that EB’s transactions from its mempool. If the certified EB arrives after the RB body, we remove its TXs from the mempool once it arrives.
 
+### Bounded mempools
+
+The mempool can be configured with an optional size limit, through the `leios-mempool-size-bytes` parameter. When a node tries adding a transaction to a full mempool, the transaction will go into an (unbounded) queue instead. Nodes will only announce transactions to their peers once those transactions have actually reached the mempool.
+
+If a node has received an EB which references transactions, and those transactions are in the queue but not yet in the mempool, the node will announce those transactions to its peer as well. This is to simulate the behavior of the real protocol, where nodes may request transactions from an EB separately from the TxSubmission mini-protocol.
+
 ## New parameters
 
 |Name|Description|Default value|

sim-rs/sim-cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sim-cli"
-version = "1.3.1"
+version = "1.4.0"
 edition = "2024"
 default-run = "sim-cli"
 rust-version = "1.88"

sim-rs/sim-cli/src/events/aggregate.rs

@@ -232,7 +232,7 @@ impl TraceAggregator {
         let new_chunk = (event.time_s - Timestamp::zero()).as_millis() / 250;
         self.current_time = event.time_s;
         if current_chunk != new_chunk {
-            if new_chunk % 4 == 0 {
+            if new_chunk.is_multiple_of(4) {
                 let timestamp = Timestamp::from_secs((new_chunk / 4) as u64);
                 self.tx_counts.push(self.produce_tx_counts(timestamp));
             }

sim-rs/sim-core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sim-core"
-version = "1.3.1"
+version = "1.4.0"
 edition = "2024"
 rust-version = "1.88"
 

sim-rs/sim-core/src/config.rs

@@ -74,6 +74,7 @@ pub struct RawParameters {
     pub leios_ib_generation_time_ms: f64,
     pub leios_mempool_sampling_strategy: MempoolSamplingStrategy,
     pub leios_mempool_aggressive_pruning: bool,
+    pub leios_mempool_size_bytes: Option<u64>,
     pub praos_chain_quality: u64,
     pub praos_fallback_enabled: bool,
     pub linear_vote_stage_length_slots: u64,
@@ -716,6 +717,7 @@ pub struct SimConfiguration {
     pub(crate) relay_strategy: RelayStrategy,
     pub(crate) mempool_strategy: MempoolSamplingStrategy,
     pub(crate) mempool_aggressive_pruning: bool,
+    pub(crate) mempool_size_bytes: u64,
     pub(crate) praos_chain_quality: u64,
     pub(crate) block_generation_probability: f64,
     pub(crate) ib_generation_probability: f64,
@@ -742,7 +744,7 @@ pub struct SimConfiguration {
 
 impl SimConfiguration {
     pub fn build(params: RawParameters, mut topology: Topology) -> Result<Self> {
-        if params.ib_shards % params.ib_shard_group_count != 0 {
+        if !params.ib_shards.is_multiple_of(params.ib_shard_group_count) {
             bail!(
                 "ib-shards ({}) is not divisible by ib-shard-group-count ({})",
                 params.ib_shards,
@@ -751,7 +753,9 @@ impl SimConfiguration {
         }
         if matches!(params.leios_variant, LeiosVariant::FullWithoutIbs)
             && params.ib_shard_group_count != 1
-            && params.ib_shard_period_length_slots % params.leios_stage_length_slots != 0
+            && !params
+                .ib_shard_period_length_slots
+                .is_multiple_of(params.leios_stage_length_slots)
         {
             bail!(
                 "Invalid sharding configuration. EBs are generated every {} slot(s). This sim is configured to choose EB shards from 1 of {} groups, using a different group every {} slot(s). Some groups would never be chosen.",
@@ -782,6 +786,7 @@ impl SimConfiguration {
             relay_strategy: params.relay_strategy,
             mempool_strategy: params.leios_mempool_sampling_strategy,
             mempool_aggressive_pruning: params.leios_mempool_aggressive_pruning,
+            mempool_size_bytes: params.leios_mempool_size_bytes.unwrap_or(u64::MAX),
             praos_chain_quality: params.praos_chain_quality,
             block_generation_probability: params.rb_generation_probability,
             ib_generation_probability: params.ib_generation_probability,

sim-rs/sim-core/src/sim/leios.rs

@@ -414,7 +414,7 @@ impl NodeImpl for LeiosNode {
     }
 
     fn handle_new_slot(&mut self, slot: u64) -> EventResult {
-        if slot % self.sim_config.stage_length == 0 {
+        if slot.is_multiple_of(self.sim_config.stage_length) {
             // A new stage has begun.
 
             // Decide how many votes to generate in each slot