SQL queries time out; readiness follows the data store

Cluster rehearsal 3: with PostgreSQL paused (docker pause, so its
kernel still answered TCP keepalives), requests on connections already
checked out hung until it came back, and /healthz/ready stayed 200
through the outage. #41 bounded getting a connection, not using one.

Client-side query limits (store::backend::query_timeout). Every
operation on a PostgreSQL or MySQL connection now runs under a time
limit. A server-side statement_timeout (or MySQL's MAX_EXECUTION_TIME,
which covers SELECTs only) can't do this: the server that would enforce
it is the one not answering. When an operation runs out, its connection
is closed instead of pooled, since a query may still be in flight on it
or a transaction open: deadpool's Object::take on PostgreSQL;
Conn::disconnect on MySQL, which marks the connection closed before it
sends anything, so the pool discards it even when the server never
answers.

- query, 2 minutes: reads, writes (the whole transaction with its
  retries), blobs, SQL lookups, search queries and indexing. These take
  milliseconds; two minutes leaves room for a large blob over a slow
  link and still ends a hang.
- maintenance, 30 minutes: range deletes (account removal, purges),
  unindexing, purge_store, and creating tables and indexes at startup,
  which can legitimately run long in one statement. Their existing
  chunked fallback for server-side statement timeouts is unchanged.
- iterate (exports, reindexing, maintenance scans) can run for hours,
  so the query limit bounds each wait for the database (preparing, the
  query starting, the next row) rather than the whole scan.

The limits are fixed, like the pool timeouts; the DataStore schema has
no field for them. Tests set them with Store::with_query_timeouts
(test_mode only).

Readiness. /healthz/ready answered 200 whenever a data store was
configured. It now reads one key from the data store with a 2 s limit
and reuses the answer for 2 s, so probes can't load the database;
while one probe runs, others get the last answer. The first failed
probe of an outage is logged. /healthz/live stays 200: restarting a
node doesn't bring its database back, and an orchestrator restarting on
failed liveness would restart every node at once. The container
HEALTHCHECK already uses /healthz/live.

Tests, store::pool_timeout (a proxy that stops forwarding while
keeping connections open plays the paused database):
- postgres_query_timeout, mysql_query_timeout (new): with four pooled
  connections open, a read, a scan and a write each fail with "Query
  timed out" 2.0 s after the pause (2 s test limit); once the proxy
  forwards again the store answers. With the limits set to an hour
  (upstream's behavior), the read was still waiting at the test's 20 s
  limit.
- postgres_readiness (new, STORE=PostgreSql): a node's data store
  goes through the proxy; /healthz/ready is 200, 503 about 4 s after
  the pause while /healthz/live stays 200, and 200 again about 2 s
  after it ends.
- postgres_pool_timeout, mysql_pool_timeout: pass as before.
store::store_tests (PostgreSql, MySql, including the MariaDB statement
timeout step) and store::task_locks (PostgreSql) pass;
store::search_tests (PostgreSql) fails at the same ordering assertion
(query.rs:684) as on main.

crates/common/src/config/inner.rs

@@ -94,6 +94,7 @@ impl Data {
             span_id_gen: id_generator,
             queue_status: true.into(),
             settings_reload: Default::default(),
+            store_health: Default::default(),
             applications,
             logos: Default::default(),
             smtp_connectors: TlsConnectors::try_new().failed("Failed to build TLS connectors"),
@@ -237,6 +238,7 @@ impl Default for Data {
             registry_id_gen: Default::default(),
             queue_status: true.into(),
             settings_reload: Default::default(),
+            store_health: Default::default(),
             applications: WebApplications::new(),
             logos: Default::default(),
             smtp_connectors: TlsConnectors::try_new().unwrap(),

crates/common/src/lib.rs

@@ -163,6 +163,8 @@ pub struct Data {
     pub queue_status: AtomicBool,
     // inbuxa: coalesces the settings reloads registry writes trigger
     pub settings_reload: cache::reload::SettingsReloadGate,
+    // inbuxa: the readiness probe's cached answer
+    pub store_health: storage::ready::StoreHealth,
 
     pub applications: WebApplications,
     pub logos: Mutex<AHashMap<Box<str>, LogoCache>>,

crates/common/src/storage/mod.rs

@@ -26,6 +26,7 @@ pub mod document;
 pub mod encryption;
 pub mod index;
 pub mod quota;
+pub mod ready; // inbuxa: readiness follows the data store
 pub mod state;
 pub mod transaction;
 

crates/common/src/storage/ready.rs

@@ -0,0 +1,83 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Readiness that reflects the data store.
+//!
+//! /healthz/ready used to answer 200 whenever a data store was configured,
+//! so a load balancer kept sending traffic to a node through a database
+//! outage. It now reads one key from the data store, with a short time
+//! limit, and caches the answer for a couple of seconds so probes can't load
+//! the database. Liveness stays 200: restarting a node doesn't bring its
+//! database back, and an orchestrator that restarts on failed liveness would
+//! otherwise restart every node at once.
+
+use crate::Server;
+use parking_lot::Mutex;
+use std::{
+    sync::atomic::{AtomicBool, Ordering},
+    time::{Duration, Instant},
+};
+use store::{ValueKey, write::ValueClass};
+
+/// How long a probe's answer is reused.
+pub const READY_CACHE: Duration = Duration::from_secs(2);
+/// How long a probe waits for the data store.
+pub const READY_PROBE_TIMEOUT: Duration = Duration::from_secs(2);
+
+#[derive(Default)]
+pub struct StoreHealth {
+    last: Mutex<Option<(Instant, bool)>>,
+    probing: AtomicBool,
+}
+
+/// Clears the probing flag even when the request is dropped mid-probe.
+struct ProbeGuard<'x>(&'x AtomicBool);
+
+impl Drop for ProbeGuard<'_> {
+    fn drop(&mut self) {
+        self.0.store(false, Ordering::Release);
+    }
+}
+
+impl Server {
+    /// Whether the data store answers: a cached result younger than
+    /// READY_CACHE, or a fresh read bounded by READY_PROBE_TIMEOUT. While
+    /// one probe is running, other callers get the last answer.
+    pub async fn is_data_store_ready(&self) -> bool {
+        let store = &self.core.storage.data;
+        if store.is_none() {
+            return false;
+        }
+        let health = &self.inner.data.store_health;
+        let last = *health.last.lock();
+        if let Some((at, ready)) = last
+            && at.elapsed() < READY_CACHE
+        {
+            return ready;
+        }
+        if health.probing.swap(true, Ordering::AcqRel) {
+            return last.is_none_or(|(_, ready)| ready);
+        }
+        let _guard = ProbeGuard(&health.probing);
+
+        let ready = tokio::time::timeout(
+            READY_PROBE_TIMEOUT,
+            store.get_value::<u64>(ValueKey::from(ValueClass::Property(0))),
+        )
+        .await
+        .is_ok_and(|result| result.is_ok());
+        // Say so once per outage, not on every probe
+        if !ready && last.is_none_or(|(_, ready)| ready) {
+            trc::event!(
+                Store(trc::StoreEvent::UnexpectedError),
+                Details = "Readiness probe: the data store didn't answer",
+                Limit = READY_PROBE_TIMEOUT,
+            );
+        }
+        *health.last.lock() = Some((Instant::now(), ready));
+        ready
+    }
+}

crates/http/src/request.rs

@@ -553,8 +553,10 @@ impl ParseHttp for Server {
                         return Ok(JsonProblemResponse(StatusCode::OK).into_http_response());
                     }
                     "ready" => {
+                        // inbuxa: ready only while the data store answers
+                        // (a cached, time-limited read); liveness stays 200
                         return Ok(JsonProblemResponse({
-                            if !self.core.storage.data.is_none() {
+                            if self.is_data_store_ready().await {
                                 StatusCode::OK
                             } else {
                                 StatusCode::SERVICE_UNAVAILABLE

crates/store/src/backend/mod.rs

@@ -30,6 +30,9 @@ pub mod s3;
 pub mod sqlite;
 // inbuxa: scale-out storage (sharded stores)
 pub mod scaleout;
+// inbuxa: client-side SQL query limits
+#[cfg(any(feature = "postgres", feature = "mysql"))]
+pub mod query_timeout;
 
 
 pub const MAX_TOKEN_LENGTH: usize = (u8::MAX >> 1) as usize;

crates/store/src/backend/mysql/blob.rs

@@ -10,7 +10,7 @@ use std::ops::Range;
 
 use mysql_async::prelude::Queryable;
 
-use super::{MysqlStore, into_error};
+use super::{MysqlStore, bounded, into_error};
 
 impl MysqlStore {
     pub(crate) async fn get_blob(
@@ -19,6 +19,8 @@ impl MysqlStore {
         range: Range<usize>,
     ) -> trc::Result<Option<Vec<u8>>> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prep("SELECT v FROM t WHERE k = ?")
                 .await
@@ -38,10 +40,15 @@ impl MysqlStore {
                     }
                 })
                 .map_err(into_error)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn put_blob(&self, key: &[u8], data: &[u8]) -> trc::Result<()> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prep("INSERT INTO t (k, v) VALUES (?, ?) ON DUPLICATE KEY UPDATE v = VALUES(v)")
                 .await
@@ -50,10 +57,15 @@ impl MysqlStore {
                 .await
                 .map_err(into_error)
                 .map(|_| ())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn delete_blob(&self, key: &[u8]) -> trc::Result<bool> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prep("DELETE FROM t WHERE k = ?")
                 .await
@@ -62,5 +74,8 @@ impl MysqlStore {
                 .await
                 .map_err(into_error)
                 .map(|hits| hits.affected_rows() > 0)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }

crates/store/src/backend/mysql/lookup.rs

@@ -10,7 +10,7 @@ use mysql_async::{Params, Row, prelude::Queryable};
 
 use crate::{IntoRows, QueryResult, QueryType, Value};
 
-use super::{MysqlStore, into_error};
+use super::{MysqlStore, bounded, into_error};
 
 impl MysqlStore {
     pub(crate) async fn sql_query<T: QueryResult>(
@@ -19,6 +19,8 @@ impl MysqlStore {
         params: &[Value<'_>],
     ) -> trc::Result<T> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn.prep(query).await.map_err(into_error)?;
             let params = Params::Positional(params.iter().map(Into::into).collect());
 
@@ -40,6 +42,9 @@ impl MysqlStore {
                     .await
                     .map_or_else(|e| Err(into_error(e)), |r| Ok(T::from_query_all(r))),
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/mysql/main.rs

@@ -6,7 +6,7 @@
  * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
-use super::{MysqlStore, into_error};
+use super::{MysqlStore, bounded, into_error};
 use crate::{
     backend::mysql::MysqlSearchField,
     search::{
@@ -72,6 +72,7 @@ impl MysqlStore {
                             .db_name(Some(replica.database.clone()))
                             .tcp_port(replica.port as u16),
                     ),
+                    timeouts: Default::default(),
                 })),
                 replica.host,
                 replica.port as u16,
@@ -81,6 +82,7 @@ impl MysqlStore {
 
         let primary = Store::MySQL(Arc::new(MysqlStore {
             conn_pool: Pool::new(opts),
+            timeouts: Default::default(),
         }));
 
         // ST-1: no replicas, no change
@@ -99,7 +101,8 @@ impl MysqlStore {
 
     pub(crate) async fn create_storage_tables(&self) -> trc::Result<()> {
         let mut conn = self.conn().await?;
-
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             for table in [
                 SUBSPACE_ACL,
                 SUBSPACE_TASK_QUEUE,
@@ -169,11 +172,15 @@ impl MysqlStore {
             }
 
             Ok(())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn create_search_tables(&self) -> trc::Result<()> {
         let mut conn = self.conn().await?;
-
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             create_search_tables::<EmailSearchField>(&mut conn).await?;
             create_search_tables::<CalendarSearchField>(&mut conn).await?;
             create_search_tables::<ContactSearchField>(&mut conn).await?;
@@ -181,6 +188,9 @@ impl MysqlStore {
             create_search_tables::<TracingSearchField>(&mut conn).await?;
 
             Ok(())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/mysql/mod.rs

@@ -6,6 +6,7 @@
  * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
+use crate::backend::query_timeout::QueryTimeouts;
 use crate::{
     search::{
         CalendarSearchField, ContactSearchField, EmailSearchField, FileSearchField, SearchField,
@@ -14,7 +15,7 @@ use crate::{
     write::SearchIndex,
 };
 use mysql_async::Pool;
-use std::fmt::Display;
+use std::{fmt::Display, time::Duration};
 
 pub mod blob;
 pub mod lookup;
@@ -25,6 +26,8 @@ pub mod write;
 
 pub struct MysqlStore {
     pub(crate) conn_pool: Pool,
+    /// inbuxa: client-side query limits (see backend::query_timeout)
+    pub(crate) timeouts: QueryTimeouts,
 }
 
 /// inbuxa: how long a request waits for a pooled connection (including
@@ -54,6 +57,43 @@ pub(crate) async fn pool_conn(
     }
 }
 
+/// inbuxa: the error for an operation that ran past its time limit.
+pub(crate) fn query_timeout_error(limit: Duration) -> trc::Error {
+    trc::StoreEvent::MysqlError
+        .reason("Query timed out")
+        .details(format!(
+            "No answer from the database within {} s",
+            limit.as_secs()
+        ))
+}
+
+/// inbuxa: ends an operation run on `conn` under `limit`. When it ran out,
+/// the connection is closed rather than returned to the pool: a query may
+/// still be in flight on it, or a transaction open. Conn::disconnect marks
+/// the connection closed before it sends anything, so even when the server
+/// doesn't answer and the attempt is dropped, the pool discards it instead
+/// of waiting to clean it up.
+pub(crate) fn bounded<T>(
+    conn: mysql_async::Conn,
+    result: Result<trc::Result<T>, tokio::time::error::Elapsed>,
+    limit: Duration,
+) -> trc::Result<T> {
+    match result {
+        Ok(result) => result,
+        Err(_) => {
+            discard(conn);
+            Err(query_timeout_error(limit))
+        }
+    }
+}
+
+/// inbuxa: closes a connection whose state is unknown (see bounded).
+pub(crate) fn discard(conn: mysql_async::Conn) {
+    tokio::spawn(async move {
+        let _ = tokio::time::timeout(Duration::from_secs(1), conn.disconnect()).await;
+    });
+}
+
 #[inline(always)]
 pub(crate) fn into_error(err: impl Display) -> trc::Error {
     trc::StoreEvent::MysqlError.reason(err)

crates/store/src/backend/mysql/read.rs

@@ -6,7 +6,7 @@
  * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
-use super::{MysqlStore, into_error, is_timeout_error};
+use super::{MysqlStore, bounded, discard, into_error, is_timeout_error, query_timeout_error};
 use crate::{Deserialize, IterateParams, Key, ValueKey, write::ValueClass};
 use futures::TryStreamExt;
 use mysql_async::{Row, prelude::Queryable};
@@ -17,6 +17,8 @@ impl MysqlStore {
         U: Deserialize + 'static,
     {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prep(format!(
                     "SELECT v FROM {} WHERE k = ?",
@@ -35,10 +37,15 @@ impl MysqlStore {
                         Ok(None)
                     }
                 })
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn key_exists(&self, key: impl Key) -> trc::Result<bool> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prep(format!(
                     "SELECT 1 FROM {} WHERE k = ?",
@@ -51,6 +58,9 @@ impl MysqlStore {
                 .await
                 .map_err(into_error)
                 .map(|r| r.is_some())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn iterate<T: Key>(
@@ -64,12 +74,14 @@ impl MysqlStore {
         let end = params.end.serialize(0);
         let keys = if params.values { "k, v" } else { "k" };
 
-        let s = conn
+        // inbuxa: a scan may run for hours, so the query limit bounds each
-            .prep(&match (params.first, params.ascending) {
+        // wait for the database (preparing, the query starting, the next
+        // row) rather than the scan. A wait that runs out closes the
+        // connection.
+        let limit = self.timeouts.query;
+        let query = match (params.first, params.ascending) {
             (true, true) => {
-                    format!(
+                format!("SELECT {keys} FROM {table} WHERE k >= ? AND k <= ? ORDER BY k ASC LIMIT 1")
-                        "SELECT {keys} FROM {table} WHERE k >= ? AND k <= ? ORDER BY k ASC LIMIT 1"
-                    )
             }
             (true, false) => {
                 format!(
@@ -82,10 +94,16 @@ impl MysqlStore {
             (false, false) => {
                 format!("SELECT {keys} FROM {table} WHERE k >= ? AND k <= ? ORDER BY k DESC")
             }
-            })
+        };
-            .await
+        let s = match tokio::time::timeout(limit, conn.prep(&query)).await {
-            .map_err(into_error)?;
+            Ok(s) => s.map_err(into_error)?,
+            Err(_) => {
+                discard(conn);
+                return Err(query_timeout_error(limit));
+            }
+        };
         let mut from = begin;
+        let mut stalled = false;
         let mut to = end;
         let mut resume_key = None;
 
@@ -94,13 +112,26 @@ impl MysqlStore {
             let mut timed_out = false;
 
             {
-                let mut rows = conn
+                let mut rows = match tokio::time::timeout(
-                    .exec_stream::<Row, _, _>(&s, (from.clone(), to.clone()))
+                    limit,
+                    conn.exec_stream::<Row, _, _>(&s, (from.clone(), to.clone())),
+                )
                 .await
-                    .map_err(into_error)?;
+                {
+                    Ok(rows) => rows.map_err(into_error)?,
+                    // Leaves the scan loop for the timeout below
+                    Err(_) => break,
+                };
 
                 loop {
-                    match rows.try_next().await {
+                    let next = match tokio::time::timeout(limit, rows.try_next()).await {
+                        Ok(next) => next,
+                        Err(_) => {
+                            stalled = true;
+                            break;
+                        }
+                    };
+                    match next {
                         Ok(Some(mut row)) => {
                             let value = if params.values {
                                 row.take_opt::<Vec<u8>, _>(1)
@@ -136,6 +167,10 @@ impl MysqlStore {
                 }
             }
 
+            if stalled {
+                break;
+            }
+
             match last_key {
                 Some(last_key) if timed_out => {
                     if params.ascending {
@@ -148,6 +183,9 @@ impl MysqlStore {
                 _ => return Ok(()),
             }
         }
+
+        discard(conn);
+        Err(query_timeout_error(limit))
     }
 
     pub(crate) async fn get_counter(
@@ -158,6 +196,8 @@ impl MysqlStore {
         let table = char::from(key.subspace());
         let key = key.serialize(0);
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prep(format!("SELECT v FROM {table} WHERE k = ?"))
                 .await
@@ -167,5 +207,8 @@ impl MysqlStore {
                 Ok(None) => Ok(0),
                 Err(e) => Err(into_error(e)),
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }

crates/store/src/backend/mysql/search.rs

@@ -10,8 +10,8 @@ use crate::{
     backend::{
         MAX_TOKEN_LENGTH,
         mysql::{
-            DELETE_CHUNK_SIZE, MIN_DELETE_CHUNK_SIZE, MysqlSearchField, MysqlStore, into_error,
+            DELETE_CHUNK_SIZE, MIN_DELETE_CHUNK_SIZE, MysqlSearchField, MysqlStore, bounded,
-            is_timeout_error,
+            into_error, is_timeout_error,
         },
     },
     search::{
@@ -27,6 +27,8 @@ use std::fmt::Write;
 impl MysqlStore {
     pub async fn index(&self, documents: Vec<IndexDocument>) -> trc::Result<()> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let mut tx_opts = TxOpts::default();
             tx_opts
                 .with_consistent_snapshot(false)
@@ -78,6 +80,9 @@ impl MysqlStore {
             }
 
             trx.commit().await.map_err(into_error)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub async fn query<R: SearchDocumentId>(
@@ -97,12 +102,17 @@ impl MysqlStore {
         }
 
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn.prep(query).await.map_err(into_error)?;
 
             conn.exec::<i64, _, _>(s, params)
                 .await
                 .map(|r| r.into_iter().map(|r| R::from_u64(r as u64)).collect())
                 .map_err(into_error)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub async fn unindex(&self, filter: SearchQuery) -> trc::Result<u64> {
@@ -111,6 +121,8 @@ impl MysqlStore {
         let params = build_filter(&mut query, &filter.filters);
 
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             let s = conn.prep(&query).await.map_err(into_error)?;
 
             match conn.exec_drop(s, params.clone()).await {
@@ -137,7 +149,9 @@ impl MysqlStore {
                             }
                             deleted += affected;
                         }
-                    Err(err) if is_timeout_error(&err) && chunk_size > MIN_DELETE_CHUNK_SIZE => {
+                        Err(err)
+                            if is_timeout_error(&err) && chunk_size > MIN_DELETE_CHUNK_SIZE =>
+                        {
                             chunk_size = (chunk_size / 2).max(MIN_DELETE_CHUNK_SIZE);
                             break;
                         }
@@ -145,6 +159,9 @@ impl MysqlStore {
                     }
                 }
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/mysql/write.rs

@@ -6,7 +6,9 @@
  * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
-use super::{DELETE_CHUNK_SIZE, MIN_DELETE_CHUNK_SIZE, MysqlStore, into_error, is_timeout_error};
+use super::{
+    DELETE_CHUNK_SIZE, MIN_DELETE_CHUNK_SIZE, MysqlStore, bounded, into_error, is_timeout_error,
+};
 use crate::{
     IndexKey, Key, LogKey, SUBSPACE_COUNTER, SUBSPACE_IN_MEMORY_COUNTER, SUBSPACE_QUOTA,
     SUBSPACE_REGISTRY_IDX,
@@ -32,7 +34,8 @@ impl MysqlStore {
         let start = Instant::now();
         let mut retry_count = 0;
         let mut conn = self.conn().await?;
-
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             loop {
                 let err = match self.write_trx(&mut conn, &mut batch).await {
                     Ok(result) => {
@@ -67,6 +70,9 @@ impl MysqlStore {
                 tokio::time::sleep(Duration::from_millis(backoff)).await;
                 retry_count += 1;
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     async fn write_trx(
@@ -385,15 +391,22 @@ impl MysqlStore {
 
     pub(crate) async fn purge_store(&self) -> trc::Result<()> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             for subspace in [SUBSPACE_QUOTA, SUBSPACE_COUNTER, SUBSPACE_IN_MEMORY_COUNTER] {
                 purge_table(&mut conn, char::from(subspace)).await?;
             }
 
             Ok(())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn delete_range(&self, from: impl Key, to: impl Key) -> trc::Result<()> {
         let mut conn = self.conn().await?;
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             let table = char::from(from.subspace());
             let mut from = from.serialize(0);
             let to = to.serialize(0);
@@ -450,6 +463,9 @@ impl MysqlStore {
                     }
                 }
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/postgres/blob.rs

@@ -2,13 +2,15 @@
  * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ *
+ * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
 use std::ops::Range;
 
 use crate::backend::postgres::into_pool_error;
 
-use super::{PostgresStore, into_error};
+use super::{PostgresStore, bounded, into_error};
 
 impl PostgresStore {
     pub(crate) async fn get_blob(
@@ -17,6 +19,8 @@ impl PostgresStore {
         range: Range<usize>,
     ) -> trc::Result<Option<Vec<u8>>> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached("SELECT v FROM t WHERE k = $1")
                 .await
@@ -39,10 +43,15 @@ impl PostgresStore {
                     }
                 })
                 .map_err(into_error)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn put_blob(&self, key: &[u8], data: &[u8]) -> trc::Result<()> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached(
                     "INSERT INTO t (k, v) VALUES ($1, $2) ON CONFLICT (k) DO UPDATE SET v = EXCLUDED.v",
@@ -53,10 +62,15 @@ impl PostgresStore {
                 .await
                 .map_err(into_error)
                 .map(|_| ())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn delete_blob(&self, key: &[u8]) -> trc::Result<bool> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached("DELETE FROM t WHERE k = $1")
                 .await
@@ -65,5 +79,8 @@ impl PostgresStore {
                 .await
                 .map_err(into_error)
                 .map(|hits| hits > 0)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }

crates/store/src/backend/postgres/lookup.rs

@@ -2,6 +2,8 @@
  * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ *
+ * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
 use crate::{QueryResult, QueryType, backend::postgres::into_pool_error};
@@ -12,7 +14,7 @@ use tokio_postgres::types::{FromSql, ToSql, Type};
 
 use crate::IntoRows;
 
-use super::{PostgresStore, into_error};
+use super::{PostgresStore, bounded, into_error};
 
 impl PostgresStore {
     pub(crate) async fn sql_query<T: QueryResult>(
@@ -21,6 +23,8 @@ impl PostgresStore {
         params_: &[crate::Value<'_>],
     ) -> trc::Result<T> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn.prepare_cached(query).await.map_err(into_error)?;
             let params = params_
                 .iter()
@@ -48,6 +52,9 @@ impl PostgresStore {
                     .await
                     .map_or_else(|e| Err(into_error(e)), |r| Ok(T::from_query_all(r))),
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/postgres/main.rs

@@ -6,7 +6,7 @@
  * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
-use super::{PostgresStore, into_error};
+use super::{PostgresStore, bounded, into_error};
 use crate::{
     backend::postgres::{
         PsqlSearchField, into_pool_error,
@@ -119,6 +119,7 @@ impl PostgresStore {
                 Store::PostgreSQL(Arc::new(PostgresStore {
                     conn_pool: pool,
                     ts_configs: ts_configs.clone(),
+                    timeouts: Default::default(),
                 })),
                 replica.host,
                 replica.port as u16,
@@ -129,6 +130,7 @@ impl PostgresStore {
         let primary = Store::PostgreSQL(Arc::new(PostgresStore {
             conn_pool: primary_pool,
             ts_configs,
+            timeouts: Default::default(),
         }));
 
         // ST-1: no replicas, no change
@@ -147,7 +149,8 @@ impl PostgresStore {
 
     pub(crate) async fn create_storage_tables(&self) -> trc::Result<()> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
-
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             for table in [
                 SUBSPACE_ACL,
                 SUBSPACE_TASK_QUEUE,
@@ -213,11 +216,15 @@ impl PostgresStore {
             }
 
             Ok(())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn create_search_tables(&self) -> trc::Result<()> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
-
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             create_search_tables::<EmailSearchField>(&conn).await?;
             create_search_tables::<CalendarSearchField>(&conn).await?;
             create_search_tables::<ContactSearchField>(&conn).await?;
@@ -225,6 +232,9 @@ impl PostgresStore {
             create_search_tables::<TracingSearchField>(&conn).await?;
 
             Ok(())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/postgres/mod.rs

@@ -6,6 +6,7 @@
  * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
+use crate::backend::query_timeout::QueryTimeouts;
 use crate::{
     search::{
         CalendarSearchField, ContactSearchField, EmailSearchField, FileSearchField, SearchField,
@@ -14,7 +15,8 @@ use crate::{
     write::SearchIndex,
 };
 use ahash::AHashSet;
-use deadpool_postgres::Pool;
+use deadpool_postgres::{Object, Pool};
+use std::time::Duration;
 use tokio_postgres::error::SqlState;
 
 pub mod blob;
@@ -28,6 +30,8 @@ pub mod write;
 pub struct PostgresStore {
     pub(crate) conn_pool: Pool,
     pub(crate) ts_configs: AHashSet<&'static str>,
+    /// inbuxa: client-side query limits (see backend::query_timeout)
+    pub(crate) timeouts: QueryTimeouts,
 }
 
 #[inline(always)]
@@ -72,6 +76,34 @@ pub(crate) fn is_timeout_error(err: &tokio_postgres::Error) -> bool {
     })
 }
 
+/// inbuxa: the error for an operation that ran past its time limit.
+pub(crate) fn query_timeout_error(limit: Duration) -> trc::Error {
+    trc::StoreEvent::PostgresqlError
+        .reason("Query timed out")
+        .details(format!(
+            "No answer from the database within {} s",
+            limit.as_secs()
+        ))
+}
+
+/// inbuxa: ends an operation run on `conn` under `limit`. When it ran out,
+/// the connection is taken out of the pool and closed: a query may still be
+/// in flight on it, or a transaction open, so it can't be handed to the
+/// next caller.
+pub(crate) fn bounded<T>(
+    conn: Object,
+    result: Result<trc::Result<T>, tokio::time::error::Elapsed>,
+    limit: Duration,
+) -> trc::Result<T> {
+    match result {
+        Ok(result) => result,
+        Err(_) => {
+            drop(Object::take(conn));
+            Err(query_timeout_error(limit))
+        }
+    }
+}
+
 #[inline(always)]
 pub(crate) fn into_pool_error(err: deadpool_postgres::PoolError) -> trc::Error {
     match err {

crates/store/src/backend/postgres/read.rs

@@ -2,9 +2,11 @@
  * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ *
+ * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
-use super::{PostgresStore, into_error, is_timeout_error};
+use super::{PostgresStore, bounded, into_error, is_timeout_error, query_timeout_error};
 use crate::{
     Deserialize, IterateParams, Key, ValueKey, backend::postgres::into_pool_error,
     write::ValueClass,
@@ -17,6 +19,8 @@ impl PostgresStore {
         U: Deserialize + 'static,
     {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached(&format!(
                     "SELECT v FROM {} WHERE k = $1",
@@ -35,10 +39,15 @@ impl PostgresStore {
                         Ok(None)
                     }
                 })
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn key_exists(&self, key: impl Key) -> trc::Result<bool> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached(&format!(
                     "SELECT 1 FROM {} WHERE k = $1",
@@ -51,6 +60,9 @@ impl PostgresStore {
                 .await
                 .map_err(into_error)
                 .map(|r| r.is_some())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn iterate<T: Key>(
@@ -64,8 +76,12 @@ impl PostgresStore {
         let end = params.end.serialize(0);
         let keys = if params.values { "k, v" } else { "k" };
 
-        let s = conn
+        // inbuxa: a scan may run for hours, so the query limit bounds each
-            .prepare_cached(&match (params.first, params.ascending) {
+        // wait for the database (preparing, the query starting, the next
+        // row) rather than the scan. A wait that runs out closes the
+        // connection.
+        let limit = self.timeouts.query;
+        let query = match (params.first, params.ascending) {
             (true, true) => {
                 format!(
                     "SELECT {keys} FROM {table} WHERE k >= $1 AND k <= $2 ORDER BY k ASC LIMIT 1"
@@ -82,26 +98,43 @@ impl PostgresStore {
             (false, false) => {
                 format!("SELECT {keys} FROM {table} WHERE k >= $1 AND k <= $2 ORDER BY k DESC")
             }
-            })
+        };
-            .await.map_err(into_error)?;
+        let s = match tokio::time::timeout(limit, conn.prepare_cached(&query)).await {
+            Ok(s) => s.map_err(into_error)?,
+            Err(_) => {
+                drop(deadpool_postgres::Object::take(conn));
+                return Err(query_timeout_error(limit));
+            }
+        };
         let mut from = begin;
         let mut to = end;
         let mut resume_key: Option<Vec<u8>> = None;
 
+        let mut stalled = false;
+
         loop {
             let mut last_key = None;
             let mut timed_out = false;
 
             {
-                let rows = conn
+                let rows =
-                    .query_raw(&s, &[&from, &to])
+                    match tokio::time::timeout(limit, conn.query_raw(&s, &[&from, &to])).await {
-                    .await
+                        Ok(rows) => rows.map_err(into_error)?,
-                    .map_err(into_error)?;
+                        // Leaves the scan loop for the timeout below
+                        Err(_) => break,
+                    };
 
                 pin_mut!(rows);
 
                 loop {
-                    match rows.try_next().await {
+                    let next = match tokio::time::timeout(limit, rows.try_next()).await {
+                        Ok(next) => next,
+                        Err(_) => {
+                            stalled = true;
+                            break;
+                        }
+                    };
+                    match next {
                         Ok(Some(row)) => {
                             let key = row.try_get::<_, &[u8]>(0).map_err(into_error)?;
                             let value = if params.values {
@@ -132,6 +165,10 @@ impl PostgresStore {
                 }
             }
 
+            if stalled {
+                break;
+            }
+
             match last_key {
                 Some(last_key) if timed_out => {
                     if params.ascending {
@@ -144,6 +181,9 @@ impl PostgresStore {
                 _ => return Ok(()),
             }
         }
+
+        drop(deadpool_postgres::Object::take(conn));
+        Err(query_timeout_error(limit))
     }
 
     pub(crate) async fn get_counter(
@@ -155,6 +195,8 @@ impl PostgresStore {
         let key = key.serialize(0);
 
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached(&format!("SELECT v FROM {table} WHERE k = $1"))
                 .await
@@ -164,5 +206,8 @@ impl PostgresStore {
                 Ok(None) => Ok(0),
                 Err(e) => Err(into_error(e)),
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }

crates/store/src/backend/postgres/search.rs

@@ -10,8 +10,8 @@ use crate::{
     backend::{
         MAX_TOKEN_LENGTH,
         postgres::{
-            DELETE_CHUNK_SIZE, MIN_DELETE_CHUNK_SIZE, PostgresStore, PsqlSearchField, into_error,
+            DELETE_CHUNK_SIZE, MIN_DELETE_CHUNK_SIZE, PostgresStore, PsqlSearchField, bounded,
-            into_pool_error, is_timeout_error,
+            into_error, into_pool_error, is_timeout_error,
         },
     },
     search::{
@@ -36,6 +36,8 @@ impl PostgresStore {
 
     pub async fn index(&self, documents: Vec<IndexDocument>) -> trc::Result<()> {
         let mut conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let trx = conn
                 .build_transaction()
                 .isolation_level(IsolationLevel::ReadCommitted)
@@ -85,8 +87,8 @@ impl PostgresStore {
 
                     if let Some(value) = fields.get(field) {
                         let value_ref = format!("${}", values.len() + 1);
-                    let (text_len, language) = if let SearchValue::Text { value, language } = value
+                        let (text_len, language) =
-                    {
+                            if let SearchValue::Text { value, language } = value {
                                 (value.len(), self.ts_config(language))
                             } else {
                                 (0, PG_UNSTEMMED_LANG)
@@ -155,6 +157,9 @@ impl PostgresStore {
             }
 
             trx.commit().await.map_err(into_error)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub async fn query<R: SearchDocumentId>(
@@ -170,6 +175,8 @@ impl PostgresStore {
             build_sort(&mut query, sort);
         }
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let s = conn.prepare_cached(&query).await.map_err(into_error)?;
 
             conn.query(&s, params.as_slice())
@@ -180,6 +187,9 @@ impl PostgresStore {
                         .collect::<Result<Vec<R>, _>>()
                 })
                 .map_err(into_error)
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub async fn unindex(&self, filter: SearchQuery) -> trc::Result<u64> {
@@ -189,6 +199,8 @@ impl PostgresStore {
         let params = self.build_filter(&mut where_clause, &filter.filters);
         let params = params.iter().map(SqlParam::as_sql).collect::<Vec<_>>();
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             let s = conn
                 .prepare_cached(&format!("DELETE FROM {table}{where_clause}"))
                 .await
@@ -223,6 +235,9 @@ impl PostgresStore {
                     }
                 }
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     fn build_filter<'x>(

crates/store/src/backend/postgres/write.rs

@@ -2,9 +2,11 @@
  * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ *
+ * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
-use super::{PostgresStore, into_error, is_timeout_error};
+use super::{PostgresStore, bounded, into_error, is_timeout_error};
 use crate::{
     IndexKey, Key, LogKey, SUBSPACE_COUNTER, SUBSPACE_IN_MEMORY_COUNTER, SUBSPACE_QUOTA,
     SUBSPACE_REGISTRY_IDX,
@@ -30,6 +32,8 @@ enum CommitError {
 impl PostgresStore {
     pub(crate) async fn write(&self, mut batch: Batch<'_>) -> trc::Result<AssignedIds> {
         let mut conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.query;
+        let result = tokio::time::timeout(limit, async {
             let start = Instant::now();
             let mut retry_count = 0;
 
@@ -72,6 +76,9 @@ impl PostgresStore {
                     }
                 }
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     async fn write_trx(
@@ -393,16 +400,22 @@ impl PostgresStore {
 
     pub(crate) async fn purge_store(&self) -> trc::Result<()> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
-
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             for subspace in [SUBSPACE_QUOTA, SUBSPACE_COUNTER, SUBSPACE_IN_MEMORY_COUNTER] {
                 purge_table(&conn, char::from(subspace)).await?;
             }
 
             Ok(())
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 
     pub(crate) async fn delete_range(&self, from: impl Key, to: impl Key) -> trc::Result<()> {
         let conn = self.conn_pool.get().await.map_err(into_pool_error)?;
+        let limit = self.timeouts.maintenance;
+        let result = tokio::time::timeout(limit, async {
             let table = char::from(from.subspace());
             let mut from = from.serialize(0);
             let to = to.serialize(0);
@@ -459,6 +472,9 @@ impl PostgresStore {
                     }
                 }
             }
+        })
+        .await;
+        bounded(conn, result, limit)
     }
 }
 

crates/store/src/backend/query_timeout.rs

@@ -0,0 +1,77 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Client-side limits on SQL queries.
+//!
+//! The pool timeouts bound getting a connection, not using one. A database
+//! that stops answering while the TCP connection stays up (a paused
+//! container, a hung server whose kernel still acknowledges keepalives)
+//! left a query on a checked-out connection waiting for as long as it took.
+//! A server-side statement_timeout can't help there: the server that would
+//! enforce it is the one not answering. So each operation on a PostgreSQL
+//! or MySQL connection runs under a time limit here, and a connection whose
+//! operation ran out is closed rather than put back in the pool, since its
+//! protocol state is unknown.
+//!
+//! Two limits:
+//! - `query`, two minutes, for request-path work: reads, writes, blob
+//!   transfers, search queries and document indexing. Those take
+//!   milliseconds; two minutes leaves room for a large blob over a slow
+//!   link and still ends a hang.
+//! - `maintenance`, thirty minutes, for work that legitimately runs long in
+//!   one statement: range deletes (account removal, purges), unindexing,
+//!   and creating tables and indexes at startup.
+//!
+//! Iterating over a range (exports, reindexing, maintenance scans) can run
+//! for hours, so there the `query` limit applies to each wait for the next
+//! row instead of the whole scan.
+
+use std::time::Duration;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct QueryTimeouts {
+    pub query: Duration,
+    pub maintenance: Duration,
+}
+
+impl QueryTimeouts {
+    pub const QUERY: Duration = Duration::from_secs(120);
+    pub const MAINTENANCE: Duration = Duration::from_secs(30 * 60);
+}
+
+impl Default for QueryTimeouts {
+    fn default() -> Self {
+        Self {
+            query: Self::QUERY,
+            maintenance: Self::MAINTENANCE,
+        }
+    }
+}
+
+#[cfg(feature = "test_mode")]
+impl crate::Store {
+    /// Sets the query limits of a SQL store that was just built (tests only:
+    /// the limits aren't configurable).
+    pub fn with_query_timeouts(self, timeouts: QueryTimeouts) -> Self {
+        match self {
+            #[cfg(feature = "postgres")]
+            crate::Store::PostgreSQL(mut store) => {
+                std::sync::Arc::get_mut(&mut store)
+                    .expect("store already shared")
+                    .timeouts = timeouts;
+                crate::Store::PostgreSQL(store)
+            }
+            #[cfg(feature = "mysql")]
+            crate::Store::MySQL(mut store) => {
+                std::sync::Arc::get_mut(&mut store)
+                    .expect("store already shared")
+                    .timeouts = timeouts;
+                crate::Store::MySQL(store)
+            }
+            store => store,
+        }
+    }
+}

tests/src/store/pool_timeout.rs

@@ -9,11 +9,31 @@
 //! the pool's timeouts. Upstream's pools had none, so the worker waited for
 //! good. No database is needed: a local listener that never answers plays
 //! the server.
+//!
+//! inbuxa: the same for a database that stops answering while connections
+//! are already open (a paused container): a query on a checked-out
+//! connection ends within the query limit, the store works again once the
+//! database is back, and /healthz/ready says 503 in between while
+//! /healthz/live stays 200. These need the local test databases; a proxy
+//! that can stop forwarding plays the pause.
 
 use registry::schema::structs::DataStore;
-use std::time::{Duration, Instant};
+use std::{
-use store::{Store, ValueKey, write::ValueClass};
+    sync::{
-use tokio::net::TcpListener;
+        Arc,
+        atomic::{AtomicBool, Ordering},
+    },
+    time::{Duration, Instant},
+};
+use store::{
+    IterateParams, Store, ValueKey,
+    backend::query_timeout::QueryTimeouts,
+    write::{BatchBuilder, ValueClass},
+};
+use tokio::{
+    io::{AsyncReadExt, AsyncWriteExt},
+    net::{TcpListener, TcpStream},
+};
 
 /// Accepts connections on a local port and never sends a byte.
 async fn silent_server() -> u16 {
@@ -94,3 +114,263 @@ pub async fn mysql_pool_timeout() {
     )
     .await;
 }
+
+/// A TCP proxy to a local port that can stop forwarding, in both
+/// directions, while keeping every connection open: a paused server whose
+/// kernel still keeps the connections up.
+struct PausableProxy {
+    port: u16,
+    paused: Arc<AtomicBool>,
+}
+
+impl PausableProxy {
+    async fn start(upstream: u16) -> Self {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let port = listener.local_addr().unwrap().port();
+        let paused = Arc::new(AtomicBool::new(false));
+        let paused_ = paused.clone();
+        tokio::spawn(async move {
+            while let Ok((client, _)) = listener.accept().await {
+                let Ok(server) = TcpStream::connect(("127.0.0.1", upstream)).await else {
+                    continue;
+                };
+                let (client_rx, client_tx) = client.into_split();
+                let (server_rx, server_tx) = server.into_split();
+                tokio::spawn(forward(client_rx, server_tx, paused_.clone()));
+                tokio::spawn(forward(server_rx, client_tx, paused_.clone()));
+            }
+        });
+        PausableProxy { port, paused }
+    }
+
+    fn pause(&self, paused: bool) {
+        self.paused.store(paused, Ordering::SeqCst);
+    }
+}
+
+async fn forward(
+    mut from: tokio::net::tcp::OwnedReadHalf,
+    mut to: tokio::net::tcp::OwnedWriteHalf,
+    paused: Arc<AtomicBool>,
+) {
+    let mut buf = vec![0u8; 16384];
+    loop {
+        while paused.load(Ordering::SeqCst) {
+            tokio::time::sleep(Duration::from_millis(20)).await;
+        }
+        let n = match from.read(&mut buf).await {
+            Ok(0) | Err(_) => return,
+            Ok(n) => n,
+        };
+        // Hold what arrived while paused until the pause ends
+        while paused.load(Ordering::SeqCst) {
+            tokio::time::sleep(Duration::from_millis(20)).await;
+        }
+        if to.write_all(&buf[..n]).await.is_err() {
+            return;
+        }
+    }
+}
+
+const TEST_LIMITS: QueryTimeouts = QueryTimeouts {
+    query: Duration::from_secs(2),
+    maintenance: Duration::from_secs(3),
+};
+
+/// Opens `connections` pooled connections at once, so the operations that
+/// follow find one idle and check it out.
+async fn warm(store: &Store, connections: usize) {
+    let reads = (0..connections).map(|_| async {
+        store
+            .get_value::<u64>(ValueKey::from(ValueClass::Property(0)))
+            .await
+            .unwrap();
+    });
+    futures::future::join_all(reads).await;
+}
+
+/// With the database paused, reads, scans and writes on connections the
+/// pool already holds end in an error within the query limit; once it is
+/// back, the store works again.
+async fn assert_queries_time_out(store: Store, proxy: &PausableProxy) {
+    store.create_tables().await.unwrap();
+    warm(&store, 4).await;
+    // mysql_async resets a connection on its way back to the pool; let
+    // those finish, or the connections are stuck in the reset when the
+    // pause starts and the pool's own wait timeout answers instead
+    tokio::time::sleep(Duration::from_secs(1)).await;
+    proxy.pause(true);
+
+    let key = || ValueKey::from(ValueClass::Property(0));
+    let limit = TEST_LIMITS.query;
+    for (what, op) in [("read", 0), ("scan", 1), ("write", 2)] {
+        let started = Instant::now();
+        let result = tokio::time::timeout(Duration::from_secs(20), async {
+            match op {
+                0 => store.get_value::<u64>(key()).await.map(|_| ()),
+                1 => {
+                    store
+                        .iterate(
+                            IterateParams::new(
+                                ValueKey::from(ValueClass::Property(0)),
+                                ValueKey::from(ValueClass::Property(u8::MAX)),
+                            ),
+                            |_, _| Ok(true),
+                        )
+                        .await
+                }
+                _ => {
+                    let mut batch = BatchBuilder::new();
+                    batch
+                        .with_account_id(u32::MAX - 7)
+                        .with_collection(types::collection::Collection::Email)
+                        .with_document(0)
+                        .set(ValueClass::Property(0), 1u64.to_be_bytes().to_vec());
+                    store.write(batch.build_all()).await.map(|_| ())
+                }
+            }
+        })
+        .await;
+        let elapsed = started.elapsed();
+        match result {
+            Ok(Err(err)) => {
+                let err = format!("{err:?}");
+                println!("Paused database, {what}: {err} after {elapsed:?}");
+                assert!(err.contains("Query timed out"), "{what}: {err}");
+                assert!(
+                    elapsed >= limit && elapsed < limit * 3,
+                    "{what} ended after {elapsed:?}"
+                );
+            }
+            Ok(Ok(())) => panic!("{what} succeeded against a paused database"),
+            Err(_) => panic!("{what} still waiting after {elapsed:?}"),
+        }
+    }
+
+    proxy.pause(false);
+    tokio::time::timeout(Duration::from_secs(20), store.get_value::<u64>(key()))
+        .await
+        .expect("still waiting after the database came back")
+        .expect("the store didn't recover");
+}
+
+#[cfg(feature = "postgres")]
+#[tokio::test(flavor = "multi_thread")]
+pub async fn postgres_query_timeout() {
+    println!("Running PostgreSQL query timeout test...");
+    let DataStore::PostgreSql(mut config) =
+        crate::utils::storage::build_data_store("PostgreSql", "").await
+    else {
+        unreachable!()
+    };
+    let proxy = PausableProxy::start(config.port as u16).await;
+    config.host = "127.0.0.1".into();
+    config.port = proxy.port as u64;
+    // New connections through the paused proxy give up as quickly
+    config.timeout = Some(TEST_LIMITS.query.into());
+    let store = Store::build(DataStore::PostgreSql(config))
+        .await
+        .unwrap()
+        .with_query_timeouts(TEST_LIMITS);
+    assert_queries_time_out(store, &proxy).await;
+}
+
+#[cfg(feature = "mysql")]
+#[tokio::test(flavor = "multi_thread")]
+pub async fn mysql_query_timeout() {
+    println!("Running MySQL query timeout test...");
+    let DataStore::MySql(mut config) = crate::utils::storage::build_data_store("MySql", "").await
+    else {
+        unreachable!()
+    };
+    let proxy = PausableProxy::start(config.port as u16).await;
+    config.host = "127.0.0.1".into();
+    config.port = proxy.port as u64;
+    let store = Store::build(DataStore::MySql(config))
+        .await
+        .unwrap()
+        .with_query_timeouts(TEST_LIMITS);
+    assert_queries_time_out(store, &proxy).await;
+}
+
+/// /healthz/ready follows the data store; /healthz/live doesn't.
+#[cfg(feature = "postgres")]
+#[tokio::test(flavor = "multi_thread")]
+pub async fn postgres_readiness() {
+    use crate::utils::server::TestServerBuilder;
+    use registry::schema::enums::NetworkListenerProtocol;
+
+    const HTTP_PORT: u16 = 11_320;
+    if std::env::var("STORE").as_deref() != Ok("PostgreSql") {
+        println!("Skipping the readiness test: it runs with STORE=PostgreSql.");
+        return;
+    }
+    println!("Running readiness test...");
+
+    let test = TestServerBuilder::new("postgres_readiness")
+        .await
+        .with_listener(NetworkListenerProtocol::Http, "http", HTTP_PORT, true)
+        .await
+        .build()
+        .await;
+
+    // Point the running node's data store at the database through the proxy
+    let DataStore::PostgreSql(mut config) =
+        crate::utils::storage::build_data_store("PostgreSql", "").await
+    else {
+        unreachable!()
+    };
+    let proxy = PausableProxy::start(config.port as u16).await;
+    config.host = "127.0.0.1".into();
+    config.port = proxy.port as u64;
+    config.timeout = Some(TEST_LIMITS.query.into());
+    let store = Store::build(DataStore::PostgreSql(config))
+        .await
+        .unwrap()
+        .with_query_timeouts(TEST_LIMITS);
+    let inner = &test.server.inner;
+    let mut core = inner.shared_core.load_full().as_ref().clone();
+    core.storage.data = store;
+    inner.shared_core.store(Arc::new(core));
+
+    let health = |path: &'static str| async move {
+        reqwest::Client::builder()
+            .danger_accept_invalid_certs(true)
+            .timeout(Duration::from_secs(10))
+            .build()
+            .unwrap()
+            .get(format!("https://127.0.0.1:{HTTP_PORT}/healthz/{path}"))
+            .send()
+            .await
+            .unwrap()
+            .status()
+            .as_u16()
+    };
+    let wait_for = |path: &'static str, status: u16| async move {
+        let started = Instant::now();
+        loop {
+            let got = health(path).await;
+            if got == status {
+                println!("/healthz/{path}: {got} after {:?}", started.elapsed());
+                return;
+            }
+            assert!(
+                started.elapsed() < Duration::from_secs(20),
+                "/healthz/{path} still {got}, expected {status}"
+            );
+            tokio::time::sleep(Duration::from_millis(250)).await;
+        }
+    };
+
+    wait_for("ready", 200).await;
+    proxy.pause(true);
+    wait_for("ready", 503).await;
+    assert_eq!(health("live").await, 200);
+    proxy.pause(false);
+    wait_for("ready", 200).await;
+    assert_eq!(health("live").await, 200);
+
+    if test.is_reset() {
+        test.temp_dir.delete();
+    }
+}