BLAH

Signed-off-by: Tristan Partin <tristan@neon.tech>

Cargo.lock

@@ -3270,11 +3270,11 @@ dependencies = [
 
 [[package]]
 name = "inotify"
-version = "0.9.6"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8069d3ec154eb856955c1c0fbffefbf5f3c40a104ec912d4797314c1801abff"
+checksum = "f37dccff2791ab604f9babef0ba14fbe0be30bd368dc541e2b08d07c8aa908f3"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.8.0",
  "inotify-sys",
  "libc",
 ]
@@ -3772,18 +3772,6 @@ dependencies = [
  "adler2",
 ]
 
-[[package]]
-name = "mio"
-version = "0.8.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
-dependencies = [
- "libc",
- "log",
- "wasi 0.11.0+wasi-snapshot-preview1",
- "windows-sys 0.48.0",
-]
-
 [[package]]
 name = "mio"
 version = "1.0.3"
@@ -3791,6 +3779,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2886843bf800fba2e3377cff24abf6379b4c4d5c6681eaf9ea5b0d15090450bd"
 dependencies = [
  "libc",
+ "log",
  "wasi 0.11.0+wasi-snapshot-preview1",
  "windows-sys 0.52.0",
 ]
@@ -3868,23 +3857,29 @@ checksum = "38bf9645c8b145698bb0b18a4637dcacbc421ea49bef2317e4fd8065a387cf21"
 
 [[package]]
 name = "notify"
-version = "6.1.1"
+version = "8.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6205bd8bb1e454ad2e27422015fb5e4f2bcc7e08fa8f27058670d208324a4d2d"
+checksum = "2fee8403b3d66ac7b26aee6e40a897d85dc5ce26f44da36b8b73e987cc52e943"
 dependencies = [
  "bitflags 2.8.0",
- "crossbeam-channel",
  "filetime",
  "fsevent-sys",
  "inotify",
  "kqueue",
  "libc",
  "log",
- "mio 0.8.11",
+ "mio",
+ "notify-types",
  "walkdir",
- "windows-sys 0.48.0",
+ "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "notify-types"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e0826a989adedc2a244799e823aece04662b66609d96af8dff7ac6df9a8925d"
+
 [[package]]
 name = "ntapi"
 version = "0.4.1"
@@ -7190,7 +7185,7 @@ dependencies = [
  "backtrace",
  "bytes",
  "libc",
- "mio 1.0.3",
+ "mio",
  "parking_lot 0.12.1",
  "pin-project-lite",
  "signal-hook-registry",

Cargo.toml

@@ -126,9 +126,7 @@ measured = { version = "0.0.22", features=["lasso"] }
 measured-process = { version = "0.0.22" }
 memoffset = "0.9"
 nix = { version = "0.27", features = ["dir", "fs", "process", "socket", "signal", "poll"] }
-# Do not update to >= 7.0.0, at least. The update will have a significant impact
-# on compute startup metrics (start_postgres_ms), >= 25% degradation.
-notify = "6.0.0"
+notify = "8.0.0"
 num_cpus = "1.15"
 num-traits = "0.2.15"
 once_cell = "1.13"

compute_tools/src/pg_helpers.rs

@@ -2,7 +2,7 @@ use std::collections::HashMap;
 use std::fmt::Write;
 use std::fs;
 use std::fs::File;
-use std::io::{BufRead, BufReader};
+use std::io::{BufRead, BufReader, Seek};
 use std::os::unix::fs::PermissionsExt;
 use std::path::Path;
 use std::process::Child;
@@ -335,10 +335,25 @@ pub fn wait_for_postgres(pg: &mut Child, pgdata: &Path) -> Result<()> {
         }
     };
 
-    watcher.watch(pgdata, RecursiveMode::NonRecursive)?;
+    // You cannot actually watch a file before it exists, so let's create the
+    // the postmaster.pid file for Postgres, so we can watch it even before
+    // Postgres actually starts. In the event that it already exists, just open
+    // the file for reading. Remember that we are racing Postgres here and that
+    // it doesn't matter who creates the postmaster.pid.
+    let mut file = match File::create(&pid_path) {
+        Ok(file) => file,
+        Err(e) => {
+            if e.kind() != std::io::ErrorKind::AlreadyExists {
+                return Err(anyhow::anyhow!(e));
+            }
+
+            File::open(&pid_path)?
+        }
+    };
+
+    watcher.watch(&pid_path, RecursiveMode::NonRecursive)?;
 
     let started_at = Instant::now();
-    let mut postmaster_pid_seen = false;
     loop {
         if let Ok(Some(status)) = pg.try_wait() {
             // Postgres exited, that is not what we expected, bail out earlier.
@@ -355,31 +370,18 @@ pub fn wait_for_postgres(pg: &mut Child, pgdata: &Path) -> Result<()> {
             debug!("swallowing extra event: {res:?}");
         }
 
-        // Check that we can open pid file first.
-        if let Ok(file) = File::open(&pid_path) {
-            if !postmaster_pid_seen {
-                debug!("postmaster.pid appeared");
-                watcher
-                    .unwatch(pgdata)
-                    .expect("Failed to remove pgdata dir watch");
-                watcher
-                    .watch(&pid_path, RecursiveMode::NonRecursive)
-                    .expect("Failed to add postmaster.pid file watch");
-                postmaster_pid_seen = true;
-            }
+        file.seek(std::io::SeekFrom::Start(0)).unwrap();
+        let reader = BufReader::new(&file);
+        let last_line = reader.lines().last();
 
-            let file = BufReader::new(file);
-            let last_line = file.lines().last();
+        // Pid file could be there and we could read it, but it could be empty, for example.
+        if let Some(Ok(line)) = last_line {
+            let status = line.trim();
+            debug!("last line of postmaster.pid: {status:?}");
 
-            // Pid file could be there and we could read it, but it could be empty, for example.
-            if let Some(Ok(line)) = last_line {
-                let status = line.trim();
-                debug!("last line of postmaster.pid: {status:?}");
-
-                // Now Postgres is ready to accept connections
-                if status == "ready" {
-                    break;
-                }
+            // Now Postgres is ready to accept connections
+            if status == "ready" {
+                break;
             }
         }
 

vendor/revisions.json

@@ -1,7 +1,7 @@
 {
   "v17": [
     "17.4",
-    "e5e87b9f52d0eaeb83f3e2517bb9727aac37729b"
+    "4cf26c355142dc9009042dbc90e0231a6218fe0d"
   ],
   "v16": [
     "16.8",