feat: Make max_active_txns actually configurable

conduwuit-example.toml

@@ -290,6 +290,15 @@
 #
 #max_fetch_prev_events = 192
 
+# How many incoming federation transactions the server is willing to be
+# processing at any given time before it becomes overloaded and starts
+# rejecting further transactions until some slots become available.
+#
+# Setting this value too low or too high may result in unstable
+# federation, and setting it too high may cause runaway resource usage.
+#
+#max_concurrent_inbound_transactions = 150
+
 # Default/base connection timeout (seconds). This is used only by URL
 # previews and update/news endpoint checks.
 #

src/api/server/send.rs

@@ -151,11 +151,7 @@ async fn process_inbound_transaction(
 		.filter_map(Result::ok)
 		.stream();
 
-	info!(
-		pdus = body.pdus.len(),
-		edus = body.edus.len(),
-		"Processing transaction",
-	);
+	info!(pdus = body.pdus.len(), edus = body.edus.len(), "Processing transaction",);
 	let Ok(results) = handle(&services, &client, body.origin(), txn_start_time, pdus, edus).await
 	else {
 		// TODO: handle this properly. The channel doesn't like being closed with no

src/core/config/mod.rs

@@ -368,6 +368,17 @@ pub struct Config {
 	#[serde(default = "default_max_fetch_prev_events")]
 	pub max_fetch_prev_events: u16,
 
+	/// How many incoming federation transactions the server is willing to be
+	/// processing at any given time before it becomes overloaded and starts
+	/// rejecting further transactions until some slots become available.
+	///
+	/// Setting this value too low or too high may result in unstable
+	/// federation, and setting it too high may cause runaway resource usage.
+	///
+	/// default: 150
+	#[serde(default = "default_max_concurrent_inbound_transactions")]
+	pub max_concurrent_inbound_transactions: usize,
+
 	/// Default/base connection timeout (seconds). This is used only by URL
 	/// previews and update/news endpoint checks.
 	///
@@ -2540,6 +2551,8 @@ fn default_pusher_idle_timeout() -> u64 { 15 }
 
 fn default_max_fetch_prev_events() -> u16 { 192_u16 }
 
+fn default_max_concurrent_inbound_transactions() -> usize { 150 }
+
 fn default_tracing_flame_filter() -> String {
 	cfg!(debug_assertions)
 		.then_some("trace,h2=off")

src/service/transaction_ids/mod.rs

@@ -37,7 +37,7 @@ impl crate::Service for Service {
 			},
 			servername_txnid_response_cache: Arc::new(SyncRwLock::new(HashMap::new())),
 			servername_txnid_active: Arc::new(SyncRwLock::new(HashMap::new())),
-			max_active_txns: 50, // TODO: fetch from config
+			max_active_txns: args.depend::<crate::config::Service>("config").max_concurrent_inbound_transactions
 		}))
 	}