From c66eb6d864cd87f1b1f18d04abf354ff5fe483a8 Mon Sep 17 00:00:00 2001
From: Bryan Stitt <bryan@llamanodes.com>
Date: Tue, 16 May 2023 12:18:59 -0700
Subject: [PATCH] head latency instead of peak latency for now

---
 TODO.md                          |  2 +-
 latency/src/ewma.rs              | 16 +++++++++-------
 web3_proxy/src/rpcs/consensus.rs |  9 +++++----
 web3_proxy/src/rpcs/one.rs       | 15 ++++++++-------
 4 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/TODO.md b/TODO.md
index b405b251..195c293d 100644
--- a/TODO.md
+++ b/TODO.md
@@ -745,4 +745,4 @@ in another repo: event subscriber
 - [ ] tests for config reloading
 - [ ] use pin instead of arc for a bunch of things?
   - https://fasterthanli.me/articles/pin-and-suffering
-- [ ] calculate archive depth automatically based on block_data_limits 
+- [ ] calculate archive depth automatically based on block_data_limits 
\ No newline at end of file
diff --git a/latency/src/ewma.rs b/latency/src/ewma.rs
index 073dad54..fe5b51f9 100644
--- a/latency/src/ewma.rs
+++ b/latency/src/ewma.rs
@@ -17,18 +17,19 @@ impl Serialize for EwmaLatency {
 }
 
 impl EwmaLatency {
-    #[inline(always)]
+    #[inline]
     pub fn record(&mut self, duration: Duration) {
         self.record_ms(duration.as_secs_f64() * 1000.0);
     }
 
-    #[inline(always)]
+    #[inline]
     pub fn record_ms(&mut self, milliseconds: f64) {
-        self.ewma.add(milliseconds);
+        // don't let it go under 0.1ms
+        self.ewma.add(milliseconds.max(0.1));
     }
 
     /// Current EWMA value in milliseconds
-    #[inline(always)]
+    #[inline]
     pub fn value(&self) -> f64 {
         self.ewma.value()
     }
@@ -36,10 +37,11 @@ impl EwmaLatency {
 
 impl Default for EwmaLatency {
     fn default() -> Self {
-        // TODO: what should the default span be? 25 requests?
-        let span = 25.0;
+        // TODO: what should the default span be? 10 requests?
+        let span = 10.0;
 
-        let start = 1000.0;
+        // TODO: what should the defautt start be?
+        let start = 1.0;
 
         Self::new(span, start)
     }
diff --git a/web3_proxy/src/rpcs/consensus.rs b/web3_proxy/src/rpcs/consensus.rs
index fbe10fa6..f2a4b576 100644
--- a/web3_proxy/src/rpcs/consensus.rs
+++ b/web3_proxy/src/rpcs/consensus.rs
@@ -7,7 +7,7 @@ use derive_more::Constructor;
 use ethers::prelude::{H256, U64};
 use hashbrown::{HashMap, HashSet};
 use itertools::{Itertools, MinMaxResult};
-use log::{trace, warn};
+use log::{debug, info, trace, warn};
 use moka::future::Cache;
 use serde::Serialize;
 use std::cmp::Reverse;
@@ -266,15 +266,16 @@ impl ConsensusFinder {
     async fn insert(&mut self, rpc: Arc<Web3Rpc>, block: Web3ProxyBlock) -> Option<Web3ProxyBlock> {
         let first_seen = self
             .first_seen
-            .get_with_by_ref(block.hash(), async move { Instant::now() })
+            .get_with_by_ref(block.hash(), async { Instant::now() })
             .await;
 
-        // TODO: this should be 0 if we are first seen, but i think it will be slightly non-zero.
-        // calculate elapsed time before trying to lock.
+        // calculate elapsed time before trying to lock
         let latency = first_seen.elapsed();
 
+        // record the time behind the fastest node
         rpc.head_latency.write().record(latency);
 
+        // update the local mapping of rpc -> block
         self.rpc_heads.insert(rpc, block)
     }
 
diff --git a/web3_proxy/src/rpcs/one.rs b/web3_proxy/src/rpcs/one.rs
index b9faea75..686e20d2 100644
--- a/web3_proxy/src/rpcs/one.rs
+++ b/web3_proxy/src/rpcs/one.rs
@@ -70,7 +70,6 @@ pub struct Web3Rpc {
     /// Track head block latency
     pub(super) head_latency: RwLock<EwmaLatency>,
     /// Track peak request latency
-    ///
     /// This is only inside an Option so that the "Default" derive works. it will always be set.
     pub(super) peak_latency: Option<PeakEwmaLatency>,
     /// Track total requests served
@@ -236,16 +235,18 @@ impl Web3Rpc {
     }
 
     pub fn peak_ewma(&self) -> OrderedFloat<f64> {
-        let peak_latency = if let Some(peak_latency) = self.peak_latency.as_ref() {
-            peak_latency.latency().as_secs_f64()
-        } else {
-            0.0
-        };
+        // TODO: bug inside peak ewma somewhere. possible with atomics being relaxed or the conversion to pair and back
+        // let peak_latency = if let Some(peak_latency) = self.peak_latency.as_ref() {
+        //     peak_latency.latency().as_secs_f64()
+        // } else {
+        //     0.0
+        // };
+        let head_latency = self.head_latency.read().value();
 
         // TODO: what ordering?
         let active_requests = self.active_requests.load(atomic::Ordering::Acquire) as f64 + 1.0;
 
-        OrderedFloat(peak_latency * active_requests)
+        OrderedFloat(head_latency * active_requests)
     }
 
     // TODO: would be great if rpcs exposed this. see https://github.com/ledgerwatch/erigon/issues/6391