From b6e1b90b3bbd685b2512bea41beadc48354865ee Mon Sep 17 00:00:00 2001
From: Robin Appelman <robin@icewind.nl>
Date: Wed, 10 Nov 2021 14:51:07 +0100
Subject: [PATCH] apply random offset to debounce timings to better spread peak
load
Signed-off-by: Robin Appelman <robin@icewind.nl>
---
Cargo.lock | 2 --
src/message.rs | 40 +++++++++++++++++++++++++---------------
2 files changed, 25 insertions(+), 17 deletions(-)
diff --git a/Cargo.lock b/Cargo.lock
index 31e40f6..e830a8a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,7 +1,5 @@
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
-version = 3
-
[[package]]
name = "addr2line"
version = "0.16.0"
diff --git a/src/message.rs b/src/message.rs
index f4c4aec..9c948d1 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -1,4 +1,5 @@
use parse_display::Display;
+use rand::{thread_rng, Rng};
use serde_json::Value;
use std::fmt::Write;
use std::sync::atomic::{AtomicBool, Ordering};
@@ -84,19 +85,25 @@ impl DebounceMap {
}
pub fn get_held_messages(&self) -> impl Iterator<Item = MessageType> {
- self.file_held
- .then(|| MessageType::File)
+ let file_opt = if self.file_held {
+ Some(MessageType::File)
+ } else {
+ None
+ };
+ let activity_opt = if self.activity_held {
+ Some(MessageType::Activity)
+ } else {
+ None
+ };
+ let notification_opt = if self.notification_held {
+ Some(MessageType::Notification)
+ } else {
+ None
+ };
+ file_opt
.into_iter()
- .chain(
- self.activity_held
- .then(|| MessageType::Activity)
- .into_iter(),
- )
- .chain(
- self.notification_held
- .then(|| MessageType::Notification)
- .into_iter(),
- )
+ .chain(activity_opt.into_iter())
+ .chain(notification_opt.into_iter())
}
fn get_last_send(&self, ty: &MessageType) -> Instant {
@@ -109,10 +116,13 @@ impl DebounceMap {
}
fn set_last_send(&mut self, ty: &MessageType) {
+ // apply a randomized offset to the last_send
+ // this helps mitigate against load bursts from many clients receiving the same updates
+ let spread = Duration::from_millis(thread_rng().gen_range(0..1000));
match ty {
- MessageType::File => self.file = Instant::now(),
- MessageType::Activity => self.activity = Instant::now(),
- MessageType::Notification => self.notification = Instant::now(),
+ MessageType::File => self.file = Instant::now() - spread,
+ MessageType::Activity => self.activity = Instant::now() - spread,
+ MessageType::Notification => self.notification = Instant::now() - spread,
MessageType::Custom(..) => {} // no debouncing for custom messages
}
}
--
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