Update comments

pageserver/src/bin/pageserver.rs

@@ -20,6 +20,7 @@ use slog::Drain;
 use pageserver::{page_service, tui, zenith_repo_dir, PageServerConf};
 
 const DEFAULT_GC_HORIZON: u64 = 0; //64 * 1024 * 1024;
+const DEFAULT_GC_PERIOD_SEC: u32 = 1; 
 
 fn main() -> Result<()> {
     let arg_matches = App::new("Zenith page server")
@@ -63,7 +64,7 @@ fn main() -> Result<()> {
         daemonize: false,
         interactive: false,
         gc_horizon: DEFAULT_GC_HORIZON,
-        gc_period: Duration::from_secs(10),
+        gc_period: Duration::from_secs(DEFAULT_GC_PERIOD_SEC),
         listen_addr: "127.0.0.1:5430".parse().unwrap(),
     };
 

pageserver/src/walredo.rs

@@ -80,11 +80,17 @@ pub fn wal_redo_main(conf: &PageServerConf, timelineid: ZTimelineId) {
 
             let result = handle_apply_request(&pcache, &process, &runtime, request);
             if result.is_err() {
-                // On error, kill the process.
+                // Something went wrong with handling the request. It's not clear
+                // if the request was faulty, and the next request would succeed
+                // again, or if the 'postgres' process went haywire. To be safe,
+                // kill the 'postgres' process so that we will start from a clean
+                // slate, with a new process, for the next request.
                 break;
             }
         }
 
+        // Time to kill the 'postgres' process. A new one will be launched on next
+        // iteration of the loop.
         info!("killing WAL redo postgres process");
         let _ = runtime.block_on(process.stdin.get_mut().shutdown());
         let mut child = process.child;