page server: Name the threads for debugging.

src/bin/pageserver.rs

@@ -8,6 +8,7 @@ use log::*;
 use pageserver::page_service;
 use pageserver::restore_s3;
 use pageserver::walreceiver;
+use pageserver::walredo;
 
 use std::io::Error;
 
@@ -22,9 +23,11 @@ fn main() -> Result<(), Error> {
     info!("starting...");
 
     // Initialize the WAL applicator
-    let walredo_thread = thread::spawn(|| {
-        walredo::wal_applicator_main();
-    });
+    let walredo_thread = thread::Builder::new()
+        .name("WAL redo thread".into()).spawn(
+            || {
+                walredo::wal_applicator_main();
+            }).unwrap();
     threads.push(walredo_thread);
     
     // Before opening up for connections, restore the latest base backup from S3.
@@ -35,18 +38,22 @@ fn main() -> Result<(), Error> {
     // Launch the WAL receiver thread. It will try to connect to the WAL safekeeper,
     // and stream the WAL. If the connection is lost, it will reconnect on its own.
     // We just fire and forget it here.
-    let walreceiver_thread = thread::spawn(|| {
-        // thread code
-        walreceiver::thread_main();
-    });
+    let walreceiver_thread = thread::Builder::new()
+        .name("WAL receiver thread".into()).spawn(
+            || {
+                // thread code
+                walreceiver::thread_main();
+            }).unwrap();
     threads.push(walreceiver_thread);
 
     // GetPage@LSN requests are served by another thread. (It uses async I/O,
     // but the code in page_service sets up it own thread pool for that)
-    let page_server_thread = thread::spawn(|| {
-        // thread code
-        page_service::thread_main();
-    });
+    let page_server_thread = thread::Builder::new()
+        .name("Page Service thread".into()).spawn(
+            || {
+                // thread code
+                page_service::thread_main();
+            }).unwrap();
     threads.push(page_server_thread);
 
     // never returns.