Try to enable a custom postgres_exporter query.

Cargo.lock

@@ -3221,7 +3221,7 @@ dependencies = [
 [[package]]
 name = "postgres"
 version = "0.19.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=6ce32f791526e27533cab0232a6bb243b2c32584#6ce32f791526e27533cab0232a6bb243b2c32584"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=ce7260db5998fe27167da42503905a12e7ad9048#ce7260db5998fe27167da42503905a12e7ad9048"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -3234,7 +3234,7 @@ dependencies = [
 [[package]]
 name = "postgres-native-tls"
 version = "0.5.0"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=6ce32f791526e27533cab0232a6bb243b2c32584#6ce32f791526e27533cab0232a6bb243b2c32584"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=ce7260db5998fe27167da42503905a12e7ad9048#ce7260db5998fe27167da42503905a12e7ad9048"
 dependencies = [
  "native-tls",
  "tokio",
@@ -3245,7 +3245,7 @@ dependencies = [
 [[package]]
 name = "postgres-protocol"
 version = "0.6.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=6ce32f791526e27533cab0232a6bb243b2c32584#6ce32f791526e27533cab0232a6bb243b2c32584"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=ce7260db5998fe27167da42503905a12e7ad9048#ce7260db5998fe27167da42503905a12e7ad9048"
 dependencies = [
  "base64 0.20.0",
  "byteorder",
@@ -3263,7 +3263,7 @@ dependencies = [
 [[package]]
 name = "postgres-types"
 version = "0.2.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=6ce32f791526e27533cab0232a6bb243b2c32584#6ce32f791526e27533cab0232a6bb243b2c32584"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=ce7260db5998fe27167da42503905a12e7ad9048#ce7260db5998fe27167da42503905a12e7ad9048"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -4933,7 +4933,7 @@ dependencies = [
 [[package]]
 name = "tokio-postgres"
 version = "0.7.7"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=6ce32f791526e27533cab0232a6bb243b2c32584#6ce32f791526e27533cab0232a6bb243b2c32584"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=ce7260db5998fe27167da42503905a12e7ad9048#ce7260db5998fe27167da42503905a12e7ad9048"
 dependencies = [
  "async-trait",
  "byteorder",

Cargo.toml

@@ -165,11 +165,11 @@ env_logger = "0.10"
 log = "0.4"
 
 ## Libraries from neondatabase/ git forks, ideally with changes to be upstreamed
-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="6ce32f791526e27533cab0232a6bb243b2c32584" }
-postgres-native-tls = { git = "https://github.com/neondatabase/rust-postgres.git", rev="6ce32f791526e27533cab0232a6bb243b2c32584" }
-postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", rev="6ce32f791526e27533cab0232a6bb243b2c32584" }
-postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", rev="6ce32f791526e27533cab0232a6bb243b2c32584" }
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="6ce32f791526e27533cab0232a6bb243b2c32584" }
+postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="ce7260db5998fe27167da42503905a12e7ad9048" }
+postgres-native-tls = { git = "https://github.com/neondatabase/rust-postgres.git", rev="ce7260db5998fe27167da42503905a12e7ad9048" }
+postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", rev="ce7260db5998fe27167da42503905a12e7ad9048" }
+postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", rev="ce7260db5998fe27167da42503905a12e7ad9048" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="ce7260db5998fe27167da42503905a12e7ad9048" }
 
 ## Other git libraries
 heapless = { default-features=false, features=[], git = "https://github.com/japaric/heapless.git", rev = "644653bf3b831c6bb4963be2de24804acf5e5001" } # upstream release pending
@@ -206,7 +206,7 @@ tonic-build = "0.9"
 
 # This is only needed for proxy's tests.
 # TODO: we should probably fork `tokio-postgres-rustls` instead.
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="6ce32f791526e27533cab0232a6bb243b2c32584" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="ce7260db5998fe27167da42503905a12e7ad9048" }
 
 ################# Binary contents sections
 

Dockerfile.compute-node

@@ -714,6 +714,23 @@ RUN wget https://github.com/pksunkara/pgx_ulid/archive/refs/tags/v0.1.3.tar.gz -
     cargo pgrx install --release && \
     echo "trusted = true" >> /usr/local/pgsql/share/extension/ulid.control
 
+#########################################################################################
+#
+# Layer "pg-wait-sampling-pg-build"
+# compile pg_wait_sampling extension
+#
+#########################################################################################
+FROM build-deps AS pg-wait-sampling-pg-build
+COPY --from=pg-build /usr/local/pgsql/ /usr/local/pgsql/
+
+ENV PATH "/usr/local/pgsql/bin/:$PATH"
+RUN wget https://github.com/postgrespro/pg_wait_sampling/archive/refs/tags/v1.1.5.tar.gz -O pg_wait_sampling.tar.gz && \
+    echo 'a03da6a413f5652ce470a3635ed6ebba528c74cb26aa4cfced8aff8a8441f81ec6dd657ff62cd6ce96a4e6ce02cad9f2519ae9525367ece60497aa20faafde5c  pg_wait_sampling.tar.gz' | sha512sum -c && \
+    mkdir pg_wait_sampling-src && cd pg_wait_sampling-src && tar xvzf ../pg_wait_sampling.tar.gz --strip-components=1 -C . && \
+    make USE_PGXS=1 -j $(getconf _NPROCESSORS_ONLN) && \
+    make USE_PGXS=1 -j $(getconf _NPROCESSORS_ONLN) install && \
+    echo 'trusted = true' >> /usr/local/pgsql/share/extension/pg_wait_sampling.control
+
 #########################################################################################
 #
 # Layer "neon-pg-ext-build"
@@ -750,6 +767,7 @@ COPY --from=rdkit-pg-build /usr/local/pgsql/ /usr/local/pgsql/
 COPY --from=pg-uuidv7-pg-build /usr/local/pgsql/ /usr/local/pgsql/
 COPY --from=pg-roaringbitmap-pg-build /usr/local/pgsql/ /usr/local/pgsql/
 COPY --from=pg-embedding-pg-build /usr/local/pgsql/ /usr/local/pgsql/
+COPY --from=pg-wait-sampling-pg-build /usr/local/pgsql/ /usr/local/pgsql/
 COPY pgxn/ pgxn/
 
 RUN make -j $(getconf _NPROCESSORS_ONLN) \

compute_tools/src/bin/compute_ctl.rs

@@ -479,6 +479,13 @@ fn cli() -> clap::Command {
                 )
                 .value_name("FILECACHE_CONNSTR"),
         )
+        .arg(
+            // DEPRECATED, NO LONGER DOES ANYTHING.
+            // See https://github.com/neondatabase/cloud/issues/7516
+            Arg::new("file-cache-on-disk")
+                .long("file-cache-on-disk")
+                .action(clap::ArgAction::SetTrue),
+        )
 }
 
 #[test]

pageserver/src/metrics.rs

@@ -638,7 +638,7 @@ const STORAGE_IO_TIME_BUCKETS: &[f64] = &[
 ///
 /// Operations:
 /// - open ([`std::fs::OpenOptions::open`])
-/// - close (dropping [`crate::virtual_file::VirtualFile`])
+/// - close (dropping [`std::fs::File`])
 /// - close-by-replace (close by replacement algorithm)
 /// - read (`read_at`)
 /// - write (`write_at`)

pageserver/src/tenant.rs

@@ -291,16 +291,6 @@ impl From<harness::TestRedoManager> for WalRedoManager {
 }
 
 impl WalRedoManager {
-    pub(crate) fn maybe_quiesce(&self, idle_timeout: Duration) {
-        match self {
-            Self::Prod(mgr) => mgr.maybe_quiesce(idle_timeout),
-            #[cfg(test)]
-            Self::Test(_) => {
-                // Not applicable to test redo manager
-            }
-        }
-    }
-
     pub async fn request_redo(
         &self,
         key: crate::repository::Key,
@@ -1659,16 +1649,22 @@ impl Tenant {
     /// This function is periodically called by compactor task.
     /// Also it can be explicitly requested per timeline through page server
     /// api's 'compact' command.
-    async fn compaction_iteration(
+    pub async fn compaction_iteration(
         &self,
         cancel: &CancellationToken,
         ctx: &RequestContext,
-    ) -> anyhow::Result<(), timeline::CompactionError> {
-        // Don't start doing work during shutdown, or when broken, we do not need those in the logs
-        if !self.is_active() {
+    ) -> anyhow::Result<()> {
+        // Don't start doing work during shutdown
+        if let TenantState::Stopping { .. } = self.current_state() {
             return Ok(());
         }
 
+        // We should only be called once the tenant has activated.
+        anyhow::ensure!(
+            self.is_active(),
+            "Cannot run compaction iteration on inactive tenant"
+        );
+
         {
             let conf = self.tenant_conf.read().unwrap();
             if !conf.location.may_delete_layers_hint() || !conf.location.may_upload_layers_hint() {

pageserver/src/tenant/storage_layer/delta_layer.rs

@@ -289,9 +289,7 @@ impl DeltaLayer {
     async fn load_inner(&self, ctx: &RequestContext) -> Result<Arc<DeltaLayerInner>> {
         let path = self.path();
 
-        let loaded = DeltaLayerInner::load(&path, None, ctx)
-            .await
-            .and_then(|res| res)?;
+        let loaded = DeltaLayerInner::load(&path, None, ctx).await?;
 
         // not production code
         let actual_filename = path.file_name().unwrap().to_owned();
@@ -612,28 +610,18 @@ impl Drop for DeltaLayerWriter {
 }
 
 impl DeltaLayerInner {
-    /// Returns nested result following Result<Result<_, OpErr>, Critical>:
-    /// - inner has the success or transient failure
-    /// - outer has the permanent failure
     pub(super) async fn load(
         path: &Utf8Path,
         summary: Option<Summary>,
         ctx: &RequestContext,
-    ) -> Result<Result<Self, anyhow::Error>, anyhow::Error> {
-        let file = match VirtualFile::open(path).await {
-            Ok(file) => file,
-            Err(e) => return Ok(Err(anyhow::Error::new(e).context("open layer file"))),
-        };
+    ) -> anyhow::Result<Self> {
+        let file = VirtualFile::open(path)
+            .await
+            .with_context(|| format!("Failed to open file '{path}'"))?;
         let file = FileBlockReader::new(file);
 
-        let summary_blk = match file.read_blk(0, ctx).await {
-            Ok(blk) => blk,
-            Err(e) => return Ok(Err(anyhow::Error::new(e).context("read first block"))),
-        };
-
-        // TODO: this should be an assertion instead; see ImageLayerInner::load
-        let actual_summary =
-            Summary::des_prefix(summary_blk.as_ref()).context("deserialize first block")?;
+        let summary_blk = file.read_blk(0, ctx).await?;
+        let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
 
         if let Some(mut expected_summary) = summary {
             // production code path
@@ -648,11 +636,11 @@ impl DeltaLayerInner {
             }
         }
 
-        Ok(Ok(DeltaLayerInner {
+        Ok(DeltaLayerInner {
             file,
             index_start_blk: actual_summary.index_start_blk,
             index_root_blk: actual_summary.index_root_blk,
-        }))
+        })
     }
 
     pub(super) async fn get_value_reconstruct_data(

pageserver/src/tenant/storage_layer/image_layer.rs

@@ -249,9 +249,7 @@ impl ImageLayer {
     async fn load_inner(&self, ctx: &RequestContext) -> Result<ImageLayerInner> {
         let path = self.path();
 
-        let loaded = ImageLayerInner::load(&path, self.desc.image_layer_lsn(), None, ctx)
-            .await
-            .and_then(|res| res)?;
+        let loaded = ImageLayerInner::load(&path, self.desc.image_layer_lsn(), None, ctx).await?;
 
         // not production code
         let actual_filename = path.file_name().unwrap().to_owned();
@@ -297,31 +295,18 @@ impl ImageLayer {
 }
 
 impl ImageLayerInner {
-    /// Returns nested result following Result<Result<_, OpErr>, Critical>:
-    /// - inner has the success or transient failure
-    /// - outer has the permanent failure
     pub(super) async fn load(
         path: &Utf8Path,
         lsn: Lsn,
         summary: Option<Summary>,
         ctx: &RequestContext,
-    ) -> Result<Result<Self, anyhow::Error>, anyhow::Error> {
-        let file = match VirtualFile::open(path).await {
-            Ok(file) => file,
-            Err(e) => return Ok(Err(anyhow::Error::new(e).context("open layer file"))),
-        };
+    ) -> anyhow::Result<Self> {
+        let file = VirtualFile::open(path)
+            .await
+            .with_context(|| format!("Failed to open file '{}'", path))?;
         let file = FileBlockReader::new(file);
-        let summary_blk = match file.read_blk(0, ctx).await {
-            Ok(blk) => blk,
-            Err(e) => return Ok(Err(anyhow::Error::new(e).context("read first block"))),
-        };
-
-        // length is the only way how this could fail, so it's not actually likely at all unless
-        // read_blk returns wrong sized block.
-        //
-        // TODO: confirm and make this into assertion
-        let actual_summary =
-            Summary::des_prefix(summary_blk.as_ref()).context("deserialize first block")?;
+        let summary_blk = file.read_blk(0, ctx).await?;
+        let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
 
         if let Some(mut expected_summary) = summary {
             // production code path
@@ -337,12 +322,12 @@ impl ImageLayerInner {
             }
         }
 
-        Ok(Ok(ImageLayerInner {
+        Ok(ImageLayerInner {
             index_start_blk: actual_summary.index_start_blk,
             index_root_blk: actual_summary.index_root_blk,
             lsn,
             file,
-        }))
+        })
     }
 
     pub(super) async fn get_value_reconstruct_data(

pageserver/src/tenant/storage_layer/layer.rs

@@ -868,9 +868,6 @@ impl LayerInner {
             }
             Ok((Err(e), _permit)) => {
                 // FIXME: this should be with the spawned task and be cancellation sensitive
-                //
-                // while we should not need this, this backoff has turned out to be useful with
-                // a bug of unexpectedly deleted remote layer file (#5787).
                 let consecutive_failures =
                     self.consecutive_failures.fetch_add(1, Ordering::Relaxed);
                 tracing::error!(consecutive_failures, "layer file download failed: {e:#}");
@@ -1199,7 +1196,7 @@ impl DownloadedLayer {
                 ));
                 delta_layer::DeltaLayerInner::load(&owner.path, summary, ctx)
                     .await
-                    .map(|res| res.map(LayerKind::Delta))
+                    .map(LayerKind::Delta)
             } else {
                 let lsn = owner.desc.image_layer_lsn();
                 let summary = Some(image_layer::Summary::expected(
@@ -1210,32 +1207,23 @@ impl DownloadedLayer {
                 ));
                 image_layer::ImageLayerInner::load(&owner.path, lsn, summary, ctx)
                     .await
-                    .map(|res| res.map(LayerKind::Image))
-            };
-
-            match res {
-                Ok(Ok(layer)) => Ok(Ok(layer)),
-                Ok(Err(transient)) => Err(transient),
-                Err(permanent) => {
-                    LAYER_IMPL_METRICS.inc_permanent_loading_failures();
-                    // TODO(#5815): we are not logging all errors, so temporarily log them **once**
-                    // here as well
-                    let permanent = permanent.context("load layer");
-                    tracing::error!("layer loading failed permanently: {permanent:#}");
-                    Ok(Err(permanent))
-                }
+                    .map(LayerKind::Image)
             }
+            // this will be a permanent failure
+            .context("load layer");
+
+            if let Err(e) = res.as_ref() {
+                LAYER_IMPL_METRICS.inc_permanent_loading_failures();
+                // TODO(#5815): we are not logging all errors, so temporarily log them here as well
+                tracing::error!("layer loading failed permanently: {e:#}");
+            }
+            res
         };
-        self.kind
-            .get_or_try_init(init)
-            // return transient errors using `?`
-            .await?
-            .as_ref()
-            .map_err(|e| {
-                // errors are not clonabled, cannot but stringify
-                // test_broken_timeline matches this string
-                anyhow::anyhow!("layer loading failed: {e:#}")
-            })
+        self.kind.get_or_init(init).await.as_ref().map_err(|e| {
+            // errors are not clonabled, cannot but stringify
+            // test_broken_timeline matches this string
+            anyhow::anyhow!("layer loading failed: {e:#}")
+        })
     }
 
     async fn get_value_reconstruct_data(

pageserver/src/tenant/tasks.rs

@@ -180,7 +180,7 @@ async fn compaction_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
                 // Run compaction
                 if let Err(e) = tenant.compaction_iteration(&cancel, &ctx).await {
                     let wait_duration = backoff::exponential_backoff_duration_seconds(
-                        error_run_count + 1,
+                        error_run_count,
                         1.0,
                         MAX_BACKOFF_SECS,
                     );
@@ -198,10 +198,6 @@ async fn compaction_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
 
             warn_when_period_overrun(started_at.elapsed(), period, BackgroundLoopKind::Compaction);
 
-            // Perhaps we did no work and the walredo process has been idle for some time:
-            // give it a chance to shut down to avoid leaving walredo process running indefinitely.
-            tenant.walredo_mgr.maybe_quiesce(period * 10);
-
             // Sleep
             if tokio::time::timeout(sleep_duration, cancel.cancelled())
                 .await
@@ -265,7 +261,7 @@ async fn gc_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
                     .await;
                 if let Err(e) = res {
                     let wait_duration = backoff::exponential_backoff_duration_seconds(
-                        error_run_count + 1,
+                        error_run_count,
                         1.0,
                         MAX_BACKOFF_SECS,
                     );

pageserver/src/walredo.rs

@@ -91,7 +91,6 @@ struct ProcessOutput {
 pub struct PostgresRedoManager {
     tenant_id: TenantId,
     conf: &'static PageServerConf,
-    last_redo_at: std::sync::Mutex<Option<Instant>>,
     redo_process: RwLock<Option<Arc<WalRedoProcess>>>,
 }
 
@@ -188,26 +187,10 @@ impl PostgresRedoManager {
         PostgresRedoManager {
             tenant_id,
             conf,
-            last_redo_at: std::sync::Mutex::default(),
             redo_process: RwLock::new(None),
         }
     }
 
-    /// This type doesn't have its own background task to check for idleness: we
-    /// rely on our owner calling this function periodically in its own housekeeping
-    /// loops.
-    pub(crate) fn maybe_quiesce(&self, idle_timeout: Duration) {
-        if let Ok(g) = self.last_redo_at.try_lock() {
-            if let Some(last_redo_at) = *g {
-                if last_redo_at.elapsed() >= idle_timeout {
-                    drop(g);
-                    let mut guard = self.redo_process.write().unwrap();
-                    *guard = None;
-                }
-            }
-        }
-    }
-
     ///
     /// Process one request for WAL redo using wal-redo postgres
     ///
@@ -222,8 +205,6 @@ impl PostgresRedoManager {
         wal_redo_timeout: Duration,
         pg_version: u32,
     ) -> anyhow::Result<Bytes> {
-        *(self.last_redo_at.lock().unwrap()) = Some(Instant::now());
-
         let (rel, blknum) = key_to_rel_block(key).context("invalid record")?;
         const MAX_RETRY_ATTEMPTS: u32 = 1;
         let mut n_attempts = 0u32;
@@ -367,13 +348,12 @@ impl PostgresRedoManager {
             self.apply_record_neon(key, &mut page, *record_lsn, record)?;
         }
         // Success!
-        let duration = start_time.elapsed();
-        // FIXME: using the same metric here creates a bimodal distribution by default, and because
-        // there could be multiple batch sizes this would be N+1 modal.
+        let end_time = Instant::now();
+        let duration = end_time.duration_since(start_time);
         WAL_REDO_TIME.observe(duration.as_secs_f64());
 
         debug!(
-            "neon applied {} WAL records in {} us to reconstruct page image at LSN {}",
+            "neon applied {} WAL records in {} ms to reconstruct page image at LSN {}",
             records.len(),
             duration.as_micros(),
             lsn

pgxn/neon/pagestore_smgr.c

@@ -1687,9 +1687,9 @@ neon_extend(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno,
 		if (current_size >= ((uint64) max_cluster_size) * 1024 * 1024)
 			ereport(ERROR,
 					(errcode(ERRCODE_DISK_FULL),
-					 errmsg("could not extend file because project size limit (%d MB) has been exceeded",
+					 errmsg("could not extend file because cluster size limit (%d MB) has been exceeded",
 							max_cluster_size),
-					 errhint("This limit is defined externally by the project size limit, and internally by neon.max_cluster_size GUC")));
+					 errhint("This limit is defined by neon.max_cluster_size GUC")));
 	}
 
 	/*

proxy/src/compute.rs

@@ -248,7 +248,6 @@ impl ConnCfg {
 
         // connect_raw() will not use TLS if sslmode is "disable"
         let (client, connection) = self.0.connect_raw(stream, tls).await?;
-        tracing::Span::current().record("pid", &tracing::field::display(client.get_process_id()));
         let stream = connection.stream.into_inner();
 
         info!(

proxy/src/proxy.rs

@@ -514,7 +514,7 @@ pub fn invalidate_cache(node_info: console::CachedNodeInfo) -> compute::ConnCfg
 }
 
 /// Try to connect to the compute node once.
-#[tracing::instrument(name = "connect_once", fields(pid = tracing::field::Empty), skip_all)]
+#[tracing::instrument(name = "connect_once", skip_all)]
 async fn connect_to_compute_once(
     node_info: &console::CachedNodeInfo,
     timeout: time::Duration,

proxy/src/serverless/conn_pool.rs

@@ -208,10 +208,6 @@ impl GlobalConnPool {
             } else {
                 info!("pool: reusing connection '{conn_info}'");
                 client.session.send(session_id)?;
-                tracing::Span::current().record(
-                    "pid",
-                    &tracing::field::display(client.inner.get_process_id()),
-                );
                 latency_timer.pool_hit();
                 latency_timer.success();
                 return Ok(Client::new(client, pool).await);
@@ -228,12 +224,6 @@ impl GlobalConnPool {
             )
             .await
         };
-        if let Ok(client) = &new_client {
-            tracing::Span::current().record(
-                "pid",
-                &tracing::field::display(client.inner.get_process_id()),
-            );
-        }
 
         match &new_client {
             // clear the hash. it's no longer valid
@@ -267,11 +257,12 @@ impl GlobalConnPool {
             }
             _ => {}
         }
-        let new_client = new_client?;
-        Ok(Client::new(new_client, pool).await)
+
+        // new_client.map(|inner| Client::new(inner, pool).await)
+        Ok(Client::new(new_client?, pool).await)
     }
 
-    fn put(&self, conn_info: &ConnInfo, client: ClientInner) -> anyhow::Result<()> {
+    fn put(&self, conn_info: &ConnInfo, client: ClientInner, pid: i32) -> anyhow::Result<()> {
         let conn_id = client.conn_id;
 
         // We want to hold this open while we return. This ensures that the pool can't close
@@ -315,9 +306,9 @@ impl GlobalConnPool {
 
         // do logging outside of the mutex
         if returned {
-            info!(%conn_id, "pool: returning connection '{conn_info}' back to the pool, total_conns={total_conns}, for this (db, user)={per_db_size}");
+            info!(%conn_id, "pool: returning connection '{conn_info}' back to the pool, total_conns={total_conns}, for this (db, user)={per_db_size}, pid={pid}");
         } else {
-            info!(%conn_id, "pool: throwing away connection '{conn_info}' because pool is full, total_conns={total_conns}");
+            info!(%conn_id, "pool: throwing away connection '{conn_info}' because pool is full, total_conns={total_conns}, pid={pid}");
         }
 
         Ok(())
@@ -394,7 +385,7 @@ impl ConnectMechanism for TokioMechanism<'_> {
 // Wake up the destination if needed. Code here is a bit involved because
 // we reuse the code from the usual proxy and we need to prepare few structures
 // that this code expects.
-#[tracing::instrument(fields(pid = tracing::field::Empty), skip_all)]
+#[tracing::instrument(skip_all)]
 async fn connect_to_compute(
     config: &config::ProxyConfig,
     conn_info: &ConnInfo,
@@ -461,7 +452,6 @@ async fn connect_to_compute_once(
         .connect_timeout(timeout)
         .connect(tokio_postgres::NoTls)
         .await?;
-    tracing::Span::current().record("pid", &tracing::field::display(client.get_process_id()));
 
     let (tx, mut rx) = tokio::sync::watch::channel(session);
 
@@ -529,6 +519,22 @@ struct ClientInner {
     conn_id: uuid::Uuid,
 }
 
+impl ClientInner {
+    pub async fn get_pid(&mut self) -> anyhow::Result<i32> {
+        let rows = self.inner.query("select pg_backend_pid();", &[]).await?;
+        if rows.len() != 1 {
+            Err(anyhow::anyhow!(
+                "expected 1 row from pg_backend_pid(), got {}",
+                rows.len()
+            ))
+        } else {
+            let pid = rows[0].get(0);
+            info!(%pid, "got pid");
+            Ok(pid)
+        }
+    }
+}
+
 impl Client {
     pub fn metrics(&self) -> Arc<MetricCounter> {
         USAGE_METRICS.register(self.inner.as_ref().unwrap().ids.clone())
@@ -540,6 +546,7 @@ pub struct Client {
     span: Span,
     inner: Option<ClientInner>,
     pool: Option<(ConnInfo, Arc<GlobalConnPool>)>,
+    pid: i32,
 }
 
 pub struct Discard<'a> {
@@ -549,11 +556,12 @@ pub struct Discard<'a> {
 
 impl Client {
     pub(self) async fn new(
-        inner: ClientInner,
+        mut inner: ClientInner,
         pool: Option<(ConnInfo, Arc<GlobalConnPool>)>,
     ) -> Self {
         Self {
             conn_id: inner.conn_id,
+            pid: inner.get_pid().await.unwrap_or(-1),
             inner: Some(inner),
             span: Span::current(),
             pool,
@@ -565,6 +573,7 @@ impl Client {
             pool,
             conn_id,
             span: _,
+            pid: _,
         } = self;
         (
             &mut inner
@@ -621,10 +630,11 @@ impl Drop for Client {
             .expect("client inner should not be removed");
         if let Some((conn_info, conn_pool)) = self.pool.take() {
             let current_span = self.span.clone();
+            let pid = self.pid;
             // return connection to the pool
             tokio::task::spawn_blocking(move || {
                 let _span = current_span.enter();
-                let _ = conn_pool.put(&conn_info, client);
+                let _ = conn_pool.put(&conn_info, client, pid);
             });
         }
     }

proxy/src/serverless/sql_over_http.rs

@@ -250,7 +250,7 @@ pub async fn handle(
     Ok(response)
 }
 
-#[instrument(name = "sql-over-http", fields(pid = tracing::field::Empty), skip_all)]
+#[instrument(name = "sql-over-http", skip_all)]
 async fn handle_inner(
     request: Request<Body>,
     sni_hostname: Option<String>,

vm-image-spec.yaml

@@ -4,15 +4,15 @@ commands:
   - name: cgconfigparser
     user: root
     sysvInitAction: sysinit
-    shell: 'cgconfigparser -l /etc/cgconfig.conf -s 1664'
+    shell: "cgconfigparser -l /etc/cgconfig.conf -s 1664"
   - name: pgbouncer
     user: nobody
     sysvInitAction: respawn
-    shell: '/usr/local/bin/pgbouncer /etc/pgbouncer.ini'
+    shell: "/usr/local/bin/pgbouncer /etc/pgbouncer.ini"
   - name: postgres-exporter
     user: nobody
     sysvInitAction: respawn
-    shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres" /bin/postgres_exporter'
+    shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres" /bin/postgres_exporter --extend.query-path /etc/postgres_exporter_queries.yml'
 shutdownHook: |
   su -p postgres --session-command '/usr/local/bin/pg_ctl stop -D /var/db/postgres/compute/pgdata -m fast --wait -t 10'
 files:
@@ -46,6 +46,21 @@ files:
           }
           memory {}
       }
+  - filename: postgres_exporter_queries.yml
+    content: |
+      postgres_exporter_pg_database_size:
+        query: "SELECT pg_database.datname, pg_database_size(pg_database.datname) as bytes, 42 as fourtytwo FROM pg_database"
+        cache_seconds: 30
+        metrics:
+          - datname:
+              usage: "LABEL"
+              description: "Name of the database"
+          - bytes:
+              usage: "GAUGE"
+              description: "Disk space used by the database"
+          - fourtytwo:
+              usage: "GAUGE"
+              description: "fourtytwo"
 build: |
   # Build cgroup-tools
   #
@@ -114,10 +129,12 @@ merge: |
 
   COPY cgconfig.conf /etc/cgconfig.conf
   COPY pgbouncer.ini /etc/pgbouncer.ini
+  COPY postgres_exporter_queries.yml /etc/postgres_exporter_queries.yml
   RUN set -e \
       && chown postgres:postgres /etc/pgbouncer.ini \
       && chmod 0644 /etc/pgbouncer.ini \
-      && chmod 0644 /etc/cgconfig.conf
+      && chmod 0644 /etc/cgconfig.conf \
+      && chmod 0644 /etc/postgres_exporter_queries.yml
 
   COPY --from=libcgroup-builder /libcgroup-install/bin/*  /usr/bin/
   COPY --from=libcgroup-builder /libcgroup-install/lib/*  /usr/lib/