Merge branch 'v3.0' into fix/issue-4855

Signed-off-by: René Cannaò <rene@proxysql.com>

Author: renecannao

include/GTID_Server_Data.h

@@ -1,5 +1,11 @@
 #ifndef CLASS_GTID_Server_Data_H
 #define CLASS_GTID_Server_Data_H
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <proxysql_gtid.h>
+
 class GTID_Server_Data {
 	public:
 	char *address;
@@ -24,4 +30,7 @@ class GTID_Server_Data {
 	void read_all_gtids();
 	void dump();
 };
+
+bool addGtidInterval(gtid_set_t& gtid_executed, std::string server_uuid, int64_t txid_start, int64_t txid_end);
+
 #endif // CLASS_GTID_Server_Data_H

include/btree.h

@@ -104,6 +104,7 @@
 #include <stddef.h>
 #include <string.h>
 #include <sys/types.h>
+#include <cstdint>
 #include <algorithm>
 #include <functional>
 #include <iostream>

include/proxysql_gtid.h

@@ -2,6 +2,7 @@
 #define PROXYSQL_GTID
 // highly inspired by libslave
 // https://github.com/vozbu/libslave/
+#include <string>
 #include <unordered_map>
 #include <list>
 #include <utility>

lib/Admin_FlushVariables.cpp

@@ -549,6 +549,36 @@ void ProxySQL_Admin::flush_mysql_variables___database_to_runtime(SQLite3DB *db,
 			flush_GENERIC_variables__checksum__database_to_runtime("mysql", checksum, epoch);
 			pthread_mutex_unlock(&GloVars.checksum_mutex);
 		}
+
+		/**
+		 * @brief Check and warn if TCP keepalive is disabled for MySQL connections.
+		 *
+		 * This safety check warns users when mysql-use_tcp_keepalive is set to false,
+		 * which can cause connection instability in certain deployment scenarios.
+		 *
+		 * @warning Disabling TCP keepalive is unsafe when ProxySQL is deployed behind:
+		 *   - Network load balancers with idle connection timeouts
+		 *   - NAT firewalls with connection state timeout
+		 *   - Cloud environments with connection pooling
+		 *   - Any intermediate network device that drops idle connections
+		 *
+		 * @why_unsafe TCP keepalive sends periodic keep-alive packets on idle connections.
+		 * When disabled:
+		 *   - Load balancers may drop connections from their connection pools
+		 *   - NAT devices may remove connection state from their tables
+		 *   - Cloud load balancers (AWS ELB, GCP Load Balancer, etc.) may terminate
+		 *     connections during idle periods
+		 *   - Results in sudden connection failures and "connection reset" errors
+		 *   - Can cause application downtime and poor user experience
+		 *
+		 * @recommendation Always set mysql-use_tcp_keepalive=true when deploying
+		 * behind load balancers or in cloud environments.
+		 */
+		// Check for TCP keepalive setting and warn if disabled
+		int mysql_use_tcp_keepalive = GloMTH->get_variable_int((char *)"use_tcp_keepalive");
+		if (mysql_use_tcp_keepalive == 0) {
+			proxy_warning("mysql-use_tcp_keepalive is set to false. This may cause connection drops when ProxySQL is behind a network load balancer. Consider setting this to true.\n");
+		}
 	}
 	if (resultset) delete resultset;
 }
@@ -885,6 +915,40 @@ void ProxySQL_Admin::flush_pgsql_variables___database_to_runtime(SQLite3DB* db,
 			GloVars.checksums_values.mysql_variables.checksum, GloVars.checksums_values.mysql_variables.epoch
 		);
 		*/
+	
+		/**
+		 * @brief Check and warn if TCP keepalive is disabled for PostgreSQL connections.
+		 *
+		 * This safety check warns users when pgsql-use_tcp_keepalive is set to false,
+		 * which can cause connection instability in certain deployment scenarios.
+		 *
+		 * @warning Disabling TCP keepalive is unsafe when ProxySQL is deployed behind:
+		 *   - Network load balancers with idle connection timeouts
+		 *   - NAT firewalls with connection state timeout
+		 *   - Cloud environments with connection pooling
+		 *   - Any intermediate network device that drops idle connections
+		 *
+		 * @why_unsafe TCP keepalive sends periodic keep-alive packets on idle connections.
+		 * When disabled for PostgreSQL:
+		 *   - Load balancers may drop connections from their connection pools
+		 *   - NAT devices may remove connection state from their tables
+		 *   - Cloud load balancers (AWS ELB, GCP Load Balancer, etc.) may terminate
+		 *     connections during idle periods
+		 *   - PostgreSQL connections may appear "stale" to the database server
+		 *   - Results in sudden connection failures and "connection reset" errors
+		 *   - Can cause application downtime and poor user experience
+		 *
+		 * @note PostgreSQL connections are often long-lived and benefit greatly from
+		 * TCP keepalive, especially in connection-pooled environments.
+		 *
+		 * @recommendation Always set pgsql-use_tcp_keepalive=true when deploying
+		 * behind load balancers or in cloud environments.
+		 */
+		// Check for TCP keepalive setting and warn if disabled
+		int pgsql_use_tcp_keepalive = GloPTH->get_variable_int((char *)"use_tcp_keepalive");
+		if (pgsql_use_tcp_keepalive == 0) {
+			proxy_warning("pgsql-use_tcp_keepalive is set to false. This may cause connection drops when ProxySQL is behind a network load balancer. Consider setting this to true.\n");
+		}
 	}
 	if (resultset) delete resultset;
 }