better avg calc

src/stats.rs

@@ -1,9 +1,10 @@
 use arc_swap::ArcSwap;
 /// Statistics and reporting.
-use log::{error, info, trace};
+use log::{error, info, trace, warn};
 use once_cell::sync::Lazy;
 use parking_lot::Mutex;
 use std::collections::HashMap;
+use std::time::SystemTime;
 use tokio::sync::mpsc::error::TrySendError;
 use tokio::sync::mpsc::{channel, Receiver, Sender};
 
@@ -346,6 +347,13 @@ impl Collector {
         // Track which state the client and server are at any given time.
         let mut client_server_states: HashMap<usize, HashMap<i32, EventName>> = HashMap::new();
 
+        // Average update times
+        let mut last_updated_avg: HashMap<usize, SystemTime> = HashMap::new();
+
+        for address_id in 0..get_number_of_addresses() {
+            last_updated_avg.insert(address_id, SystemTime::now());
+        }
+
         // Flush stats to StatsD and calculate averages every 15 seconds.
         let tx = self.tx.clone();
         tokio::task::spawn(async move {
@@ -406,6 +414,9 @@ impl Collector {
                 .entry(stat.address_id)
                 .or_insert(HashMap::new());
             let old_stats = old_stats.entry(stat.address_id).or_insert(HashMap::new());
+            let last_updated_avg = last_updated_avg
+                .entry(stat.address_id)
+                .or_insert(SystemTime::now());
 
             // Some are counters, some are gauges...
             match stat.name {
@@ -531,6 +542,24 @@ impl Collector {
                 }
 
                 EventName::UpdateAverages => {
+                    let elapsed = match last_updated_avg.elapsed() {
+                        Ok(elapsed) => elapsed.as_secs(),
+                        Err(err) => {
+                            error!(
+                                "Could not get elapsed time, averages may be incorrect: {:?}",
+                                err
+                            );
+                            STAT_PERIOD / 1_000
+                        }
+                    } as i64;
+
+                    *last_updated_avg = SystemTime::now();
+
+                    // Tokio triggers the interval on first tick and then sleeps.
+                    if elapsed == 0 {
+                        continue;
+                    }
+
                     // Calculate averages
                     for stat in &[
                         "avg_query_count",
@@ -548,7 +577,7 @@ impl Collector {
 
                         let old_value = old_stats.entry(total_name.clone()).or_insert(0);
                         let new_value = stats.get(total_name.as_str()).unwrap_or(&0).to_owned();
-                        let avg = (new_value - *old_value) / (STAT_PERIOD as i64 / 1_000); // Avg / second
+                        let avg = (new_value - *old_value) / elapsed; // Avg / second
 
                         stats.insert(stat, avg);
                         *old_value = new_value;