fix(mysql): resolve ProxySQL hostgroup lock via literal floor setup

crates/dbx-driver-mysql/src/mysql.rs

@@ -1396,7 +1396,7 @@ pub async fn connect_with_ca_cert_pool_limit_idle_and_setup_database(
         idle_timeout_secs,
         setup_database,
         extra_setup_queries,
-        MySqlSetupMode::Standard,
+        MySqlSetupMode::default_for_url(url),
     )
     .await
 }
@@ -1648,6 +1648,10 @@ const MYSQL_DEFAULT_CHARSET: &str = "utf8mb4";
 const MYSQL_LEGACY_CHARSET: &str = "utf8";
 
 impl MySqlSetupMode {
+    pub fn default_for_url(url: &str) -> Self {
+        mysql_url_setup_mode(url).unwrap_or(Self::Standard)
+    }
+
     fn group_concat_max_len_query(self, url: &str) -> Option<String> {
         match self {
             // An explicit Connector/J style `sessionVariables=group_concat_max_len=...`
@@ -1982,6 +1986,13 @@ fn mysql_group_concat_setup_fallback_mode(setup_mode: MySqlSetupMode, error: &st
     // `Unknown system variable 'group_concat_'` with `max_len` cut off
     // (issue #10197). The truncated prefix is specific enough on its own.
     let proxy_truncated_variable_rejected = lower.contains("unknown system variable 'group_concat_'");
+    // ProxySQL rejects queries with error 9006 when an unparseable expression SET
+    // (such as `cast(greatest(...))`) causes ProxySQL to lock the connection to
+    // hostgroup 0 under `mysql-set_query_lock_on_hostgroup=1`, conflicting with
+    // read/write split rules routing queries to another hostgroup (issue #11307).
+    let proxysql_hostgroup_locked = lower.contains("error 9006")
+        || (lower.contains("proxysql") && lower.contains("locked to hostgroup"))
+        || (lower.contains("connection is locked to hostgroup") && lower.contains("trying to reach hostgroup"));
     if (floor_statement_rejected && (setup_query_rejected || setup_value_rejected || setup_argument_rejected))
         || txsql_truncated_name_rejected
         || gaea_setup_expression_rejected
@@ -1989,6 +2000,7 @@ fn mysql_group_concat_setup_fallback_mode(setup_mode: MySqlSetupMode, error: &st
         || sphinxql_setup_query_rejected
         || gateway_session_variable_rejected
         || proxy_truncated_variable_rejected
+        || proxysql_hostgroup_locked
     {
         return Some(MySqlSetupMode::Compatible);
     }
@@ -2187,7 +2199,7 @@ fn mysql_ssl_opts(
 }
 
 fn mysql_setup_queries(url: &str, extra_setup_queries: &[String]) -> Vec<String> {
-    mysql_setup_queries_with_mode(url, extra_setup_queries, MySqlSetupMode::Standard)
+    mysql_setup_queries_with_mode(url, extra_setup_queries, MySqlSetupMode::default_for_url(url))
 }
 
 fn mysql_setup_queries_for_database(
@@ -2195,7 +2207,12 @@ fn mysql_setup_queries_for_database(
     setup_database: Option<&str>,
     extra_setup_queries: &[String],
 ) -> Vec<String> {
-    mysql_setup_queries_for_database_with_mode(url, setup_database, extra_setup_queries, MySqlSetupMode::Standard)
+    mysql_setup_queries_for_database_with_mode(
+        url,
+        setup_database,
+        extra_setup_queries,
+        MySqlSetupMode::default_for_url(url),
+    )
 }
 
 fn mysql_setup_queries_with_mode(url: &str, extra_setup_queries: &[String], setup_mode: MySqlSetupMode) -> Vec<String> {
@@ -2452,6 +2469,30 @@ fn mysql_local_infile_paths(url: &str) -> Vec<PathBuf> {
         .collect()
 }
 
+fn mysql_url_setup_mode(url: &str) -> Option<MySqlSetupMode> {
+    let (_, query) = url.split_once('?')?;
+    let query = query.split('#').next().unwrap_or(query);
+    for segment in query.split('&') {
+        let (key, value) = match segment.split_once('=') {
+            Some((k, v)) => (k.trim(), v.trim()),
+            None => (segment.trim(), "true"),
+        };
+        if key.eq_ignore_ascii_case("proxysql") && mysql_url_param_value_is_true(value) {
+            return Some(MySqlSetupMode::LiteralFloor);
+        }
+        if key.eq_ignore_ascii_case("setupmode") || key.eq_ignore_ascii_case("setup_mode") {
+            if value.eq_ignore_ascii_case("literalfloor") || value.eq_ignore_ascii_case("literal_floor") {
+                return Some(MySqlSetupMode::LiteralFloor);
+            } else if value.eq_ignore_ascii_case("compatible") {
+                return Some(MySqlSetupMode::Compatible);
+            } else if value.eq_ignore_ascii_case("standard") {
+                return Some(MySqlSetupMode::Standard);
+            }
+        }
+    }
+    None
+}
+
 fn split_mysql_session_variables(value: &str) -> Vec<String> {
     let chars: Vec<char> = value.chars().collect();
     let mut assignments = Vec::new();
@@ -2619,6 +2660,7 @@ async fn verify_pool_connection(pool: &MySqlPool, timeout: Duration) -> Result<(
     super::with_connection_timeout("MySQL", timeout, async {
         let mut conn = pool.get_conn().await.map_err(|e| format!("MySQL connection failed: {e}"))?;
         conn.ping().await.map_err(|e| format!("MySQL ping failed: {e}"))?;
+        conn.query_drop("SELECT 1").await.map_err(|e| format!("MySQL connection verification query failed: {e}"))?;
         Ok(())
     })
     .await
@@ -2873,6 +2915,9 @@ fn is_dbx_handled_mysql_url_param(key: &str) -> bool {
             | "forceconnectiontimezonetosession"
             | "sessionvariables"
             | "localinfilepath"
+            | "proxysql"
+            | "setupmode"
+            | "setup_mode"
     )
 }
 
@@ -9816,6 +9861,10 @@ mod tests {
             // is the floor expression failing to parse rather than the variable being
             // missing, so the literal rung still applies (issue #10197).
             "MySQL connection failed: Server error: `ERROR 1193 (HY000): Unknown system variable 'group_concat_'`",
+            // ProxySQL error 9006 when expression SET locks connection to hostgroup 0 (issue #11307).
+            "MySQL connection verification query failed: Server error: `ERROR 9006 (Y0000): ProxySQL Error: connection is locked to hostgroup 0 but trying to reach hostgroup 1`",
+            "Server error: `ERROR 9006 (Y0000): ProxySQL Error: connection is locked to hostgroup 0 but trying to reach hostgroup 1`",
+            "Server error: `ProxySQL Error: connection is locked to hostgroup 0 but trying to reach hostgroup 1`",
         ] {
             let fallback = mysql_group_concat_setup_fallback_mode(MySqlSetupMode::Standard, error)
                 .or_else(|| mysql_setup_probe_fallback_mode(MySqlSetupMode::Standard, url, error))
@@ -9828,6 +9877,65 @@ mod tests {
         }
     }
 
+    #[test]
+    fn mysql_proxysql_hostgroup_locked_error_retries_with_literal_floor() {
+        let error = "MySQL connection verification query failed: Server error: `ERROR 9006 (Y0000): ProxySQL Error: connection is locked to hostgroup 0 but trying to reach hostgroup 1`";
+        let fallback = mysql_group_concat_setup_fallback_mode(MySqlSetupMode::Standard, error)
+            .expect("ProxySQL error 9006 must trigger setup fallback");
+        assert_eq!(fallback, MySqlSetupMode::Compatible);
+        assert_eq!(
+            mysql_setup_fallback_ladder(fallback, error),
+            vec![MySqlSetupMode::Compatible, MySqlSetupMode::LiteralFloor]
+        );
+    }
+
+    #[test]
+    fn mysql_setup_mode_url_detection() {
+        assert_eq!(
+            MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app?proxysql=true"),
+            MySqlSetupMode::LiteralFloor
+        );
+        assert_eq!(
+            MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app?proxysql=1"),
+            MySqlSetupMode::LiteralFloor
+        );
+        assert_eq!(
+            MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app?setupMode=literalFloor"),
+            MySqlSetupMode::LiteralFloor
+        );
+        assert_eq!(
+            MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app?setup_mode=literal_floor"),
+            MySqlSetupMode::LiteralFloor
+        );
+        assert_eq!(
+            MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app?setupMode=compatible"),
+            MySqlSetupMode::Compatible
+        );
+        assert_eq!(
+            MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app?setupMode=standard"),
+            MySqlSetupMode::Standard
+        );
+        assert_eq!(MySqlSetupMode::default_for_url("mysql://root:pw@host:3306/app"), MySqlSetupMode::Standard);
+    }
+
+    #[test]
+    fn mysql_setup_queries_prefers_literal_floor_for_proxysql_url() {
+        let queries = mysql_setup_queries("mysql://host:3306/db?proxysql=true", &[]);
+        assert_eq!(queries, vec!["USE `db`", "SET NAMES utf8mb4", "SET SESSION group_concat_max_len = 1048576"]);
+
+        let queries_flag = mysql_setup_queries("mysql://host:3306/db?setupMode=literalFloor", &[]);
+        assert_eq!(queries_flag, vec!["USE `db`", "SET NAMES utf8mb4", "SET SESSION group_concat_max_len = 1048576"]);
+    }
+
+    #[test]
+    fn mysql_url_strips_proxysql_and_setupmode_parameters() {
+        let url = "mysql://root:pw@host:3306/app?proxysql=true&setupMode=literalFloor&require_ssl=true";
+        let async_url = mysql_async_url(url);
+        assert!(!async_url.contains("proxysql"), "{async_url}");
+        assert!(!async_url.contains("setupMode"), "{async_url}");
+        assert_eq!(async_url.as_ref(), "mysql://root:pw@host:3306/app?require_ssl=true");
+    }
+
     #[test]
     fn mysql_group_concat_variable_level_rejections_skip_the_literal_floor() {
         // These servers reject the variable itself, so the plain literal cannot help and