diff --git a/scylla/src/transport/load_balancing/default.rs b/scylla/src/transport/load_balancing/default.rs index 3667ee1f77..d58d26febe 100644 --- a/scylla/src/transport/load_balancing/default.rs +++ b/scylla/src/transport/load_balancing/default.rs @@ -2133,7 +2133,7 @@ mod latency_awareness { use itertools::Either; use scylla_cql::errors::{DbError, QueryError}; use tokio::time::{Duration, Instant}; - use tracing::{instrument::WithSubscriber, trace}; + use tracing::{instrument::WithSubscriber, trace, warn}; use uuid::Uuid; use crate::{load_balancing::NodeRef, transport::node::Node}; @@ -2192,13 +2192,37 @@ mod latency_awareness { Some(prev_avg) => Some({ let delay = (now - prev_avg.timestamp).as_secs_f64(); let scaled_delay = delay / scale_secs; - let prev_weight = (scaled_delay + 1.).ln() / scaled_delay; + let prev_weight = if scaled_delay <= 0. { + 1. + } else { + (scaled_delay + 1.).ln() / scaled_delay + }; let last_latency_secs = last_latency.as_secs_f64(); let prev_avg_secs = prev_avg.average.as_secs_f64(); - let average = Duration::from_secs_f64( + let average = match Duration::try_from_secs_f64( (1. - prev_weight) * last_latency_secs + prev_weight * prev_avg_secs, - ); + ) { + Ok(ts) => ts, + Err(e) => { + warn!( + "Error while calculating average: {e}. \ + prev_avg_secs: {prev_avg_secs}, \ + last_latency_secs: {last_latency_secs}, \ + prev_weight: {prev_weight}, \ + scaled_delay: {scaled_delay}, \ + delay: {delay}, \ + prev_avg.timestamp: {:?}, \ + now: {now:?}", + prev_avg.timestamp + ); + + // Not sure when we could enter this branch, + // so I have no idea what would be a sensible value to return here, + // this does not seem like a very bad choice. + prev_avg.average + } + }; Self { num_measures: prev_avg.num_measures + 1, timestamp: now,