Added tables 'stats_mysql_client_host_cache' and 'stats_mysql_client_host_cache_reset' exposing entries in 'client_host_cache'

include/MySQL_Thread.h

@@ -596,6 +596,15 @@ class MySQL_Threads_Handler
 	 *    - 'address_family' is either 'AF_INET' or 'AF_INET6'.
 	 *    - The address obtained from it isn't '127.0.0.1'.
 	 *
+	 *   In case 'client_sockaddr' matches the previous description, the update
+	 *   of the client host cache is performed in the following way:
+	 *     1. If the cache is full, the oldest element in the cache is searched.
+	 *     In case the oldest element address doesn't match the supplied
+	 *     address, the oldest element is removed.
+	 *     2. The cache is searched looking for the supplied address, in case of
+	 *     being found, the entry is updated, otherwise the entry is inserted in
+	 *     the cache.
+	 *
 	 * @param client_sockaddr A 'sockaddr' holding the required client information
 	 *   to update the 'client_host_cache_map'.
 	 * @param error 'true' if there was an error in the connection that should be
@@ -628,6 +637,22 @@ class MySQL_Threads_Handler
 	 * @brief Delete all the entries in the 'client_host_cache' internal map.
 	 */
 	void flush_client_host_cache();
+	/**
+	 * @brief Returns the current entries of 'client_host_cache' in a
+	 *   'SQLite3_result'. In case the param 'reset' is specified, the structure
+	 *   is cleaned after being queried.
+	 *
+	 * @param reset If 'true' the entries of the internal structure
+	 *   'client_host_cache' will be cleaned after scrapping.
+	 *
+	 * @return SQLite3_result holding the current entries of the
+	 *   'client_host_cache'. In the following format:
+	 *
+	 *    [ 'client_address', 'error_num', 'last_updated' ]
+	 *
+	 *    Where 'last_updated' is the last updated time expressed in 'ns'.
+	 */
+	SQLite3_result* get_client_host_cache(bool reset);
 	/**
 	 * @brief Callback to update the metrics.
 	 */

include/proxysql_admin.h

@@ -355,6 +355,7 @@ class ProxySQL_Admin {
 	void stats___proxysql_servers_metrics();
 	void stats___mysql_prepared_statements_info();
 	void stats___mysql_gtid_executed();
+	void stats___mysql_client_host_cache(bool reset);
 
 	// Update prometheus metrics
 	void p_stats___memory_metrics();

lib/MySQL_Thread.cpp

@@ -2443,6 +2443,77 @@ MySQL_Client_Host_Cache_Entry MySQL_Threads_Handler::find_client_host_cache(stru
 	return entry;
 }
 
+/**
+ * @brief Number of columns for representing a 'MySQL_Client_Host_Cache_Entry'
+ *   in a 'SQLite3_result'.
+ */
+const int CLIENT_HOST_CACHE_COLUMNS = 3;
+
+/**
+ * @brief Helper function that converts a given client address and a
+ *   'MySQL_Client_Host_Cache_Entry', into a row for a 'SQLite3_result' for
+ *   table 'STATS_SQLITE_TABLE_MYSQL_CLIENT_HOST_CACHE'.
+ *
+ * @param address The client address to be added to the resulset row.
+ * @param entry The 'MySQL_Client_Host_Cache_Entry' to be added to the resulset
+ *   row.
+ *
+ * @return A pointer array holding the values for each of the columns of the
+ *   row. It should be freed through helper function 'free_client_host_cache_row'.
+ */
+char** client_host_cache_entry_row(
+	const std::string address, const MySQL_Client_Host_Cache_Entry& entry
+) {
+	// INET6_ADDRSTRLEN length should be enough for holding any member:
+	//  { address: MAX INET6_ADDRSTRLEN, updated_at: uint64_t, error_count: uint32_t }
+	char buff[INET6_ADDRSTRLEN];
+	char** row =
+		static_cast<char**>(malloc(sizeof(char*)*CLIENT_HOST_CACHE_COLUMNS));
+
+	row[0]=strdup(address.c_str());
+	sprintf(buff, "%u", entry.error_count);
+	row[1]=strdup(buff);
+	sprintf(buff, "%lu", entry.updated_at);
+	row[2]=strdup(buff);
+
+	return row;
+}
+
+/**
+ * @brief Helper function to free the row returned by
+ * 'client_host_cache_entry_row'.
+ *
+ * @param row The pointer array holding the row values to be freed.
+ */
+void free_client_host_cache_row(char** row) {
+	for (int i = 0; i < CLIENT_HOST_CACHE_COLUMNS; i++) {
+		free(row[i]);
+	}
+	free(row);
+}
+
+SQLite3_result* MySQL_Threads_Handler::get_client_host_cache(bool reset) {
+	SQLite3_result *result = new SQLite3_result(CLIENT_HOST_CACHE_COLUMNS);
+
+	pthread_mutex_lock(&mutex_client_host_cache);
+	result->add_column_definition(SQLITE_TEXT,"client_address");
+	result->add_column_definition(SQLITE_TEXT,"error_count");
+	result->add_column_definition(SQLITE_TEXT,"last_updated");
+
+	for (const auto& cache_entry : client_host_cache) {
+		char** row = client_host_cache_entry_row(cache_entry.first, cache_entry.second);
+		result->add_row(row);
+		free_client_host_cache_row(row);
+	}
+
+	if (reset) {
+		client_host_cache.clear();
+	}
+
+	pthread_mutex_unlock(&mutex_client_host_cache);
+	return result;
+}
+
 void MySQL_Threads_Handler::update_client_host_cache(struct sockaddr* client_sockaddr, bool error) {
 	if (client_sockaddr->sa_family != AF_INET && client_sockaddr->sa_family != AF_INET6) {
 		return;

lib/ProxySQL_Admin.cpp

@@ -490,6 +490,9 @@ static int http_handler(void *cls, struct MHD_Connection *connection, const char
 #define STATS_SQLITE_TABLE_MYSQL_ERRORS "CREATE TABLE stats_mysql_errors (hostgroup INT NOT NULL , hostname VARCHAR NOT NULL , port INT NOT NULL , username VARCHAR NOT NULL , client_address VARCHAR NOT NULL , schemaname VARCHAR NOT NULL , errno INT NOT NULL , count_star INTEGER NOT NULL , first_seen INTEGER NOT NULL , last_seen INTEGER NOT NULL , last_error VARCHAR NOT NULL DEFAULT '' , PRIMARY KEY (hostgroup, hostname, port, username, schemaname, errno) )"
 #define STATS_SQLITE_TABLE_MYSQL_ERRORS_RESET "CREATE TABLE stats_mysql_errors_reset (hostgroup INT NOT NULL , hostname VARCHAR NOT NULL , port INT NOT NULL , username VARCHAR NOT NULL , client_address VARCHAR NOT NULL , schemaname VARCHAR NOT NULL , errno INT NOT NULL , count_star INTEGER NOT NULL , first_seen INTEGER NOT NULL , last_seen INTEGER NOT NULL , last_error VARCHAR NOT NULL DEFAULT '' , PRIMARY KEY (hostgroup, hostname, port, username, schemaname, errno) )"
 
+#define STATS_SQLITE_TABLE_MYSQL_CLIENT_HOST_CACHE "CREATE TABLE stats_mysql_client_host_cache (client_address VARCHAR NOT NULL, error_count INT NOT NULL, last_updated BIGINT NOT NULL)"
+#define STATS_SQLITE_TABLE_MYSQL_CLIENT_HOST_CACHE_RESET "CREATE TABLE stats_mysql_client_host_cache_reset (client_address VARCHAR NOT NULL, error_count INT NOT NULL, last_updated BIGINT NOT NULL)"
+
 #ifdef DEBUG
 #define ADMIN_SQLITE_TABLE_DEBUG_LEVELS "CREATE TABLE debug_levels (module VARCHAR NOT NULL PRIMARY KEY , verbosity INT NOT NULL DEFAULT 0)"
 #define ADMIN_SQLITE_TABLE_DEBUG_FILTERS "CREATE TABLE debug_filters (filename VARCHAR NOT NULL , line INT NOT NULL , funct VARCHAR NOT NULL , PRIMARY KEY (filename, line, funct) )"
@@ -2936,6 +2939,8 @@ bool ProxySQL_Admin::GenericRefreshStatistics(const char *query_no_space, unsign
 	bool stats_mysql_query_rules=false;
 	bool stats_mysql_users=false;
 	bool stats_mysql_gtid_executed=false;
+	bool stats_mysql_client_host_cache=false;
+	bool stats_mysql_client_host_cache_reset=false;
 	bool dump_global_variables=false;
 
 	bool runtime_scheduler=false;
@@ -3023,6 +3028,10 @@ bool ProxySQL_Admin::GenericRefreshStatistics(const char *query_no_space, unsign
 		{ stats_mysql_users=true; refresh=true; }
 	if (strstr(query_no_space,"stats_mysql_gtid_executed"))
 		{ stats_mysql_gtid_executed=true; refresh=true; }
+	if (strstr(query_no_space,"stats_mysql_client_host_cache"))
+		{ stats_mysql_client_host_cache=true; refresh=true; }
+	if (strstr(query_no_space,"stats_mysql_client_host_cache_reset"))
+		{ stats_mysql_client_host_cache_reset=true; refresh=true; }
 
 	if (strstr(query_no_space,"stats_proxysql_servers_checksums"))
 		{ stats_proxysql_servers_checksums = true; refresh = true; }
@@ -3163,6 +3172,13 @@ bool ProxySQL_Admin::GenericRefreshStatistics(const char *query_no_space, unsign
 			stats___mysql_prepared_statements_info();
 		}
 
+		if (stats_mysql_client_host_cache) {
+			stats___mysql_client_host_cache(false);
+		}
+		if (stats_mysql_client_host_cache_reset) {
+			stats___mysql_client_host_cache(true);
+		}
+
 		if (admin) {
 			if (dump_global_variables) {
 				pthread_mutex_lock(&GloVars.checksum_mutex);
@@ -5537,6 +5553,8 @@ bool ProxySQL_Admin::init() {
 	insert_into_tables_defs(tables_defs_stats,"stats_mysql_users", STATS_SQLITE_TABLE_MYSQL_USERS);
 	insert_into_tables_defs(tables_defs_stats,"global_variables", ADMIN_SQLITE_TABLE_GLOBAL_VARIABLES); // workaround for issue #708
 	insert_into_tables_defs(tables_defs_stats,"stats_mysql_prepared_statements_info", ADMIN_SQLITE_TABLE_STATS_MYSQL_PREPARED_STATEMENTS_INFO);
+	insert_into_tables_defs(tables_defs_stats,"stats_mysql_client_host_cache", STATS_SQLITE_TABLE_MYSQL_CLIENT_HOST_CACHE);
+	insert_into_tables_defs(tables_defs_stats,"stats_mysql_client_host_cache_reset", STATS_SQLITE_TABLE_MYSQL_CLIENT_HOST_CACHE_RESET);
 
 	// ProxySQL Cluster
 	insert_into_tables_defs(tables_defs_admin,"proxysql_servers", ADMIN_SQLITE_TABLE_PROXYSQL_SERVERS);
@@ -8770,6 +8788,50 @@ void ProxySQL_Admin::stats___mysql_query_digests(bool reset, bool copy) {
 	delete resultset;
 }
 
+void ProxySQL_Admin::stats___mysql_client_host_cache(bool reset) {
+	if (!GloQPro) return;
+
+	SQLite3_result* resultset = GloMTH->get_client_host_cache(reset);
+	if (resultset==NULL) return;
+
+	statsdb->execute("BEGIN");
+
+	int rc = 0;
+	sqlite3_stmt* statement=NULL;
+	char* query = NULL;
+
+	if (reset) {
+		query=(char*)"INSERT INTO stats_mysql_client_host_cache_reset VALUES (?1, ?2, ?3)";
+	} else {
+		query=(char*)"INSERT INTO stats_mysql_client_host_cache VALUES (?1, ?2, ?3)";
+	}
+
+	if (reset) {
+		statsdb->execute("DELETE FROM stats_mysql_client_host_cache_reset");
+	} else {
+		statsdb->execute("DELETE FROM stats_mysql_client_host_cache");
+	}
+
+	rc = statsdb->prepare_v2(query, &statement);
+	ASSERT_SQLITE_OK(rc, statsdb);
+
+	for (std::vector<SQLite3_row *>::iterator it = resultset->rows.begin() ; it != resultset->rows.end(); ++it) {
+		SQLite3_row *row = *it;
+
+		rc=(*proxy_sqlite3_bind_text)(statement, 1, row->fields[0], -1, SQLITE_TRANSIENT); ASSERT_SQLITE_OK(rc, statsdb);
+		rc=(*proxy_sqlite3_bind_int64)(statement, 2, atoll(row->fields[1])); ASSERT_SQLITE_OK(rc, statsdb);
+		rc=(*proxy_sqlite3_bind_int64)(statement, 3, atoll(row->fields[2])); ASSERT_SQLITE_OK(rc, statsdb);
+
+		SAFE_SQLITE3_STEP2(statement);
+		rc=(*proxy_sqlite3_clear_bindings)(statement);
+		rc=(*proxy_sqlite3_reset)(statement);
+	}
+
+	(*proxy_sqlite3_finalize)(statement);
+	statsdb->execute("COMMIT");
+	delete resultset;
+}
+
 void ProxySQL_Admin::stats___mysql_errors(bool reset) {
 	if (!GloQPro) return;
 	SQLite3_result * resultset=NULL;