feat: add pool-level sync_server_parameters override

Cargo.toml

@@ -1,103 +1,102 @@
 [package]
-name = "pg_doorman"
-version = "3.11.0"
 edition = "2021"
-rust-version = "1.87.0"
 license = "MIT"
-
+name = "pg_doorman"
+rust-version = "1.87.0"
+version = "3.11.1"
 
 [profile.release]
 codegen-units = 1
 lto = true
 
 [profile.profiling]
-inherits = "release"
 debug = true
+inherits = "release"
 
 [dependencies]
-tikv-jemallocator = { version = "0.6.0", features = ["background_threads_runtime_support"] }
-tikv-jemalloc-ctl = { version = "0.6.0", features = ["stats"] }
-tracing = "0.1.37"
-tracing-subscriber = { version = "0.3.20", features = ["json", "env-filter", "std"]}
-log = "0.4.27"
-clap = { version = "4.5.37", features = ["derive", "env"] }
-serde = { version = "1", features = ["derive"] }
-serde_derive = "1"
-serde_json = "1.0.140"
-serde_yaml = "0.9"
-ipnet = { version = "2.11.0", features = ["serde"] }
-once_cell = "1.21.3"
-quanta = "0.12"
 arc-swap = "1.7.1"
-toml = "0.8"
-prometheus = "0.14.0"
-tokio = { version = "1.48.4", features = ["rt-multi-thread", "fs", "parking_lot", "sync", "io-util", "net", "macros", "signal", "time"] }
-exitcode = "1.1.2"
-pin-project = "1"
+base64 = "0.22.1"
 bytes = "1.10.1"
-md-5 = "0.10"
-socket2 = { version = "0.6.1", features = ["all"] }
 chrono = "0.4"
-rand = "0.9.1"
-base64 = "0.22.1"
+clap = {version = "4.5.37", features = ["derive", "env"]}
+exitcode = "1.1.2"
 hmac = "0.12"
+include_dir = "0.7"
+ipnet = {version = "2.11.0", features = ["serde"]}
+jwt = {version = "0.16.0", features = ["openssl"]}
+libc = "0.2.172"
+log = "0.4.27"
+lru = "0.16.3"
+md-5 = "0.10"
+native-tls = {version = "0.2.14"}
+nix = {version = "0.30.1", features = ["process", "signal"]}
+num_cpus = "1.16.0"
+once_cell = "1.21.3"
+parking_lot = {version = "0.12.1", features = ["hardware-lock-elision"]}
+pin-project = "1"
+prometheus = "0.14.0"
+quanta = "0.12"
+rand = "0.9.1"
+scopeguard = "1.2"
+serde = {version = "1", features = ["derive"]}
+serde-toml-merge = {version = "0.3.8"}
+serde_derive = "1"
+serde_json = "1.0.140"
+serde_yaml = "0.9"
+sha-1 = "0.10"
 sha2 = "0.10"
+socket2 = {version = "0.6.1", features = ["all"]}
 stringprep = "0.1"
 subtle = "2"
-nix = { version = "0.30.1", features = ["process", "signal"] }
-sha-1 = "0.10"
-lru = "0.16.3"
-scopeguard = "1.2"
-parking_lot = {version = "0.12.1", features = ["hardware-lock-elision"]}
-libc = "0.2.172"
-include_dir = "0.7"
-num_cpus = "1.16.0"
 syslog = "7.0.0"
-native-tls = { version = "0.2.14" }
-tokio-native-tls = { version = "0.3.1" }
-serde-toml-merge = { version = "0.3.8"}
-jwt = { version = "0.16.0", features = ["openssl"] }
+tikv-jemalloc-ctl = {version = "0.6.0", features = ["stats"]}
+tikv-jemallocator = {version = "0.6.0", features = ["background_threads_runtime_support"]}
+tokio = {version = "1.48.4", features = ["rt-multi-thread", "fs", "parking_lot", "sync", "io-util", "net", "macros", "signal", "time"]}
+tokio-native-tls = {version = "0.3.1"}
+toml = "0.8"
+tracing = "0.1.37"
+tracing-subscriber = {version = "0.3.20", features = ["json", "env-filter", "std"]}
 # `jwt` (above) is shared with the web UI SSO flow. Both code paths
 # verify RS256 against an RSA public key loaded through openssl, so
 # adding a second JWT crate would only duplicate functionality and
 # pull extra transitive licenses (ring, ISC) into the vendor set.
-thiserror = "1"
-openssl = { version = "0.10.78" }
-openssl-sys = { version = "0.9.114" }
-iota = { version = "0.2.3" }
+iota = {version = "0.2.3"}
+openssl = {version = "0.10.78"}
+openssl-sys = {version = "0.9.114"}
+pam-client = {version = "0.5.0", optional = true}
 pin-project-lite = "0.2.16"
-pam-client = { version =  "0.5.0", optional = true }
 postgres = "0.19.10"
+thiserror = "1"
 # `with-serde_json-1` lets `Row::try_get` decode `json`/`jsonb`
 # columns directly into `serde_json::Value`, which allows auth_query
 # startup_parameters to come from a native JSON column.
-tokio-postgres = { version = "0.7", features = ["with-serde_json-1"] }
-postgres-native-tls = "0.5.1"
-flate2 = "1.0.28"
-sd-notify = "0.4"
-zerocopy = "0.8.24"
-xxhash-rust = { version = "0.8.15", features = ["xxh3"] }
 ahash = "0.8"
-smallvec = "1.13"
 dashmap = "6.1"
-reqwest = { version = "0.11", features = ["json"] }
+flate2 = "1.0.28"
 futures = "0.3"
 hdrhistogram = "7.5"
+postgres-native-tls = "0.5.1"
+reqwest = {version = "0.11", features = ["json"]}
+sd-notify = "0.4"
+smallvec = "1.13"
+tokio-postgres = {version = "0.7", features = ["with-serde_json-1"]}
+xxhash-rust = {version = "0.8.15", features = ["xxh3"]}
+zerocopy = "0.8.24"
 
 [patch.crates-io]
-native-tls = { path = "patches/rust-native-tls" }
-tokio-native-tls = { path = "patches/tokio-native-tls" }
-openssl-src = { path = "patches/openssl-src" }
+native-tls = {path = "patches/rust-native-tls"}
+openssl-src = {path = "patches/openssl-src"}
+tokio-native-tls = {path = "patches/tokio-native-tls"}
 
 [dev-dependencies]
+criterion = "0.5"
 cucumber = "0.21"
-tempfile = "3"
 portpicker = "0.1"
-tokio-postgres = "0.7"
-criterion = "0.5"
-pprof = { version = "0.14", features = ["flamegraph", "criterion"] }
-serial_test = "3"
+pprof = {version = "0.14", features = ["flamegraph", "criterion"]}
 regex = "1"
+serial_test = "3"
+tempfile = "3"
+tokio-postgres = "0.7"
 
 [[bin]]
 name = "pg_doorman"
@@ -112,38 +111,38 @@ name = "metrics_stress"
 path = "src/bin/metrics_stress.rs"
 
 [[test]]
-name = "bdd"
 harness = false
+name = "bdd"
 path = "tests/bdd/main.rs"
 
 [[test]]
-name = "patroni_proxy_bdd"
 harness = false
+name = "patroni_proxy_bdd"
 path = "src/bin/patroni_proxy/tests/bdd/main.rs"
 
 [[bench]]
-name = "hash_benchmarks"
 harness = false
+name = "hash_benchmarks"
 
 [[bench]]
-name = "cache_benchmarks"
 harness = false
+name = "cache_benchmarks"
 
 [[bench]]
-name = "coordinator_benchmarks"
 harness = false
+name = "coordinator_benchmarks"
 
 [[bench]]
-name = "log_benchmarks"
 harness = false
+name = "log_benchmarks"
 
 [[bench]]
-name = "memory_benchmarks"
 harness = false
+name = "memory_benchmarks"
 
 [[bench]]
-name = "pool_anticipation_benchmarks"
 harness = false
+name = "pool_anticipation_benchmarks"
 
 [features]
 default = []

documentation/en/src/changelog.md

@@ -1,5 +1,40 @@
 # Changelog
 
+### 3.11.1
+
+#### Pool-level `sync_server_parameters` override
+
+`sync_server_parameters` can now be set per pool in addition to the global
+`[general]` section. When a pool defines `sync_server_parameters = true`,
+client-sent session parameters (e.g. `search_path`, `work_mem`,
+`statement_timeout`) are applied via `SET` queries on checkout for that pool only. When omitted at pool level, the global setting is used.
+
+Enabling `sync_server_parameters` adds a round-trip to PostgreSQL on every
+checkout where client parameters differ from the backend defaults. This
+increases total query count and can affect TPS under high concurrency.
+Enable it only for pools that really need per-client session parameters.
+Note that parameters sent via libpq `options=-c ...` (`lock_timeout`, `statement_timeout`,
+`idle_in_transaction_session_timeout`, etc.) are not applied on the
+backend when `sync_server_parameters` is disabled.
+
+Changing `sync_server_parameters` via RELOAD takes effect immediately for new checkouts. 
+Pool connections are recreated with the updated setting. In-flight transactions are not affected -
+they continue with the server they were assigned at checkout time.
+
+In-flight backend connections retain the `search_path` that was SET at
+checkout, so a prepared statement compiled before RELOAD continues to
+target the same schema. New connections that checkout after RELOAD may
+have a different `search_path`, which causes PostgreSQL to re-plan the
+prepared statement against the new schema resolution.
+
+```toml
+[general]
+sync_server_parameters = false  # global default
+
+[pools.synced_db]
+sync_server_parameters = true   # override for this pool
+```
+
 ### 3.11.0
 
 #### Talos can route through client-specific pools

pg_doorman.toml

@@ -564,6 +564,10 @@ pool_mode = "transaction"
 # Default: true
 cleanup_server_connections = true
 
+# Override global sync_server_parameters for this pool.
+# Default: None (uses global setting)
+# sync_server_parameters = false
+
 # Override global prepared_statements_cache_size for this pool.
 # prepared_statements_cache_size = 8192
 

pg_doorman.yaml

@@ -611,6 +611,10 @@ pools:
     # Default: true
     cleanup_server_connections: true
 
+    # Override global sync_server_parameters for this pool.
+    # Default: None (uses global setting)
+    # sync_server_parameters: false
+
     # Override global prepared_statements_cache_size for this pool.
     # prepared_statements_cache_size: 8192
 

src/app/generate/annotated.rs

@@ -175,6 +175,7 @@ pub fn generate_reference_config(format: ConfigFormat, russian: bool) -> String
         server_tls_certificate: None,
         server_tls_private_key: None,
         auth_query: None,
+        sync_server_parameters: None,
         startup_parameters: std::collections::BTreeMap::new(),
         users: vec![User {
             username: "app_user".to_string(),
@@ -1385,6 +1386,14 @@ fn write_single_pool(w: &mut ConfigWriter, pool_name: &str, pool: &Pool) {
     );
     w.blank();
 
+    write_field_comment(w, fi, "pool", "sync_server_parameters");
+    if let Some(val) = pool.sync_server_parameters {
+        w.kv(fi, "sync_server_parameters", &w.bool_val(val));
+    } else {
+        w.commented_kv(fi, "sync_server_parameters", "false");
+    }
+    w.blank();
+
     write_field_desc(w, fi, "pool", "prepared_statements_cache_size");
     if let Some(val) = pool.prepared_statements_cache_size {
         w.kv(fi, "prepared_statements_cache_size", &w.num_val(val));

src/app/generate/docs.rs

@@ -293,6 +293,7 @@ fn write_pool_fields(out: &mut String, f: &FieldsData) {
         "reserve_pool_size",
         "reserve_pool_timeout",
         "min_guaranteed_pool_size",
+        "sync_server_parameters",
         "startup_parameters",
     ];
 

src/app/generate/fields.yaml

@@ -1370,6 +1370,13 @@ fields:
       doc: "Close server connections in this pool that have been opened for longer than this value, in milliseconds. Only applied to idle connections. If not specified, the global server_lifetime setting is used."
       default: "None (uses global setting)"
 
+    sync_server_parameters:
+      config:
+        en: "Override global sync_server_parameters for this pool."
+        ru: "Переопределить глобальный sync_server_parameters для этого пула."
+      doc: "Override global sync_server_parameters for this pool. When enabled, client-sent session parameters (e.g. search_path, work_mem) are applied via SET queries on checkout. If not specified, the global setting is used."
+      default: "None (uses global setting)"
+
     cleanup_server_connections:
       config:
         en: |

src/app/generate/mod.rs

@@ -168,6 +168,7 @@ pub fn generate_config_with_client(
                     server_tls_certificate: None,
                     server_tls_private_key: None,
                     auth_query: None,
+                    sync_server_parameters: None,
                     startup_parameters: std::collections::BTreeMap::new(),
                     users: users.clone(),
                 },

src/app/generate/tests.rs

@@ -86,6 +86,7 @@ pub fn generate_config_with_client<
                         server_tls_certificate: None,
                         server_tls_private_key: None,
                         auth_query: None,
+                        sync_server_parameters: None,
                         patroni_api_urls: None,
                         fallback_cooldown: None,
                         patroni_api_timeout: None,

src/config/pool.rs

@@ -173,6 +173,9 @@ pub struct Pool {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub server_tls_private_key: Option<String>,
 
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub sync_server_parameters: Option<bool>,
+
     #[serde(skip_serializing_if = "Option::is_none")]
     pub auth_query: Option<AuthQueryConfig>,
 
@@ -202,6 +205,13 @@ impl Pool {
         s.finish()
     }
 
+    /// Return the effective `sync_server_parameters` flag by falling back
+    /// to the global default when the pool-level override is `None`.
+    pub fn effective_sync_server_parameters(&self, general: &super::General) -> bool {
+        self.sync_server_parameters
+            .unwrap_or(general.sync_server_parameters)
+    }
+
     pub fn default_pool_mode() -> PoolMode {
         PoolMode::Transaction
     }
@@ -471,6 +481,7 @@ impl Default for Pool {
             server_tls_certificate: None,
             server_tls_private_key: None,
             auth_query: None,
+            sync_server_parameters: None,
             startup_parameters: std::collections::BTreeMap::new(),
         }
     }