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lewis.moe
1use crate::circuit_breaker::CircuitBreaker;
2use crate::sync::firehose::SequencedEvent;
3use reqwest::Client;
4use std::sync::atomic::{AtomicU64, Ordering};
5use std::sync::Arc;
6use std::time::Duration;
7use tokio::sync::{broadcast, watch};
8use tracing::{debug, error, info, warn};
9
10const NOTIFY_THRESHOLD_SECS: u64 = 20 * 60;
11
12pub struct Crawlers {
13 hostname: String,
14 crawler_urls: Vec<String>,
15 http_client: Client,
16 last_notified: AtomicU64,
17 circuit_breaker: Option<Arc<CircuitBreaker>>,
18}
19
20impl Crawlers {
21 pub fn new(hostname: String, crawler_urls: Vec<String>) -> Self {
22 Self {
23 hostname,
24 crawler_urls,
25 http_client: Client::builder()
26 .timeout(Duration::from_secs(30))
27 .build()
28 .unwrap_or_default(),
29 last_notified: AtomicU64::new(0),
30 circuit_breaker: None,
31 }
32 }
33
34 pub fn with_circuit_breaker(mut self, circuit_breaker: Arc<CircuitBreaker>) -> Self {
35 self.circuit_breaker = Some(circuit_breaker);
36 self
37 }
38
39 pub fn from_env() -> Option<Self> {
40 let hostname = std::env::var("PDS_HOSTNAME").ok()?;
41
42 let crawler_urls: Vec<String> = std::env::var("CRAWLERS")
43 .unwrap_or_default()
44 .split(',')
45 .filter(|s| !s.is_empty())
46 .map(|s| s.trim().to_string())
47 .collect();
48
49 if crawler_urls.is_empty() {
50 return None;
51 }
52
53 Some(Self::new(hostname, crawler_urls))
54 }
55
56 fn should_notify(&self) -> bool {
57 let now = std::time::SystemTime::now()
58 .duration_since(std::time::UNIX_EPOCH)
59 .unwrap_or_default()
60 .as_secs();
61
62 let last = self.last_notified.load(Ordering::Relaxed);
63 now - last >= NOTIFY_THRESHOLD_SECS
64 }
65
66 fn mark_notified(&self) {
67 let now = std::time::SystemTime::now()
68 .duration_since(std::time::UNIX_EPOCH)
69 .unwrap_or_default()
70 .as_secs();
71
72 self.last_notified.store(now, Ordering::Relaxed);
73 }
74
75 pub async fn notify_of_update(&self) {
76 if !self.should_notify() {
77 debug!("Skipping crawler notification due to debounce");
78 return;
79 }
80
81 if let Some(cb) = &self.circuit_breaker {
82 if !cb.can_execute().await {
83 debug!("Skipping crawler notification due to circuit breaker open");
84 return;
85 }
86 }
87
88 self.mark_notified();
89 let circuit_breaker = self.circuit_breaker.clone();
90
91 for crawler_url in &self.crawler_urls {
92 let url = format!("{}/xrpc/com.atproto.sync.requestCrawl", crawler_url.trim_end_matches('/'));
93 let hostname = self.hostname.clone();
94 let client = self.http_client.clone();
95 let cb = circuit_breaker.clone();
96
97 tokio::spawn(async move {
98 match client
99 .post(&url)
100 .json(&serde_json::json!({ "hostname": hostname }))
101 .send()
102 .await
103 {
104 Ok(response) => {
105 if response.status().is_success() {
106 debug!(crawler = %url, "Successfully notified crawler");
107 if let Some(cb) = cb {
108 cb.record_success().await;
109 }
110 } else {
111 let status = response.status();
112 let body = response.text().await.unwrap_or_default();
113 warn!(
114 crawler = %url,
115 status = %status,
116 body = %body,
117 hostname = %hostname,
118 "Crawler notification returned non-success status"
119 );
120 if let Some(cb) = cb {
121 cb.record_failure().await;
122 }
123 }
124 }
125 Err(e) => {
126 warn!(crawler = %url, error = %e, "Failed to notify crawler");
127 if let Some(cb) = cb {
128 cb.record_failure().await;
129 }
130 }
131 }
132 });
133 }
134 }
135}
136
137pub async fn start_crawlers_service(
138 crawlers: Arc<Crawlers>,
139 mut firehose_rx: broadcast::Receiver<SequencedEvent>,
140 mut shutdown: watch::Receiver<bool>,
141) {
142 info!(
143 hostname = %crawlers.hostname,
144 crawler_count = crawlers.crawler_urls.len(),
145 crawlers = ?crawlers.crawler_urls,
146 "Starting crawlers notification service"
147 );
148
149 loop {
150 tokio::select! {
151 result = firehose_rx.recv() => {
152 match result {
153 Ok(event) => {
154 if event.event_type == "commit" {
155 crawlers.notify_of_update().await;
156 }
157 }
158 Err(broadcast::error::RecvError::Lagged(n)) => {
159 warn!(skipped = n, "Crawlers service lagged behind firehose");
160 crawlers.notify_of_update().await;
161 }
162 Err(broadcast::error::RecvError::Closed) => {
163 error!("Firehose channel closed, stopping crawlers service");
164 break;
165 }
166 }
167 }
168 _ = shutdown.changed() => {
169 if *shutdown.borrow() {
170 info!("Crawlers service shutting down");
171 break;
172 }
173 }
174 }
175 }
176}