How to fix CR_STMT_CLOSED (2056): Statement closed indirectly in MySQL

if (mysql_ping(conn) != 0) {
    // Reconnect and re-prepare statements
    mysql_close(conn);
    conn = mysql_init(NULL);
    mysql_real_connect(conn, host, user, password, database, port, NULL, 0);
    // Re-prepare all statements
}

MYSQL_STMT *stmt = mysql_stmt_init(conn);
if (!stmt) {
    // Handle initialization error
}

// Prepare the statement
if (mysql_stmt_prepare(stmt, query, strlen(query)) != 0) {
    // Handle prepare error
    mysql_stmt_close(stmt);
    return;
}

// Execute and process results
if (mysql_stmt_execute(stmt) != 0) {
    // Handle execution error
}

// Always close the statement when done
mysql_stmt_close(stmt);

// When getting a connection from pool
if (connection->last_used + TIMEOUT < current_time) {
    // Connection may be stale, reset all statements
    reset_all_statements(connection);
}

// Function to reset statements
void reset_all_statements(MYSQL *conn) {
    // Close all prepared statements
    // Re-prepare necessary statements
}

-- Check current prepared statement count
SHOW STATUS LIKE 'Prepared_stmt_count';

-- Check server limits
SHOW VARIABLES LIKE 'max_prepared_stmt_count';

-- Increase limit if needed (requires server restart)
SET GLOBAL max_prepared_stmt_count = 16384;

int retry_count = 0;
int max_retries = 3;
int delay_ms = 100;

while (retry_count < max_retries) {
    int result = mysql_stmt_execute(stmt);
    if (result == 0) {
        break; // Success
    }
    
    // Check if error is CR_STMT_CLOSED (2056)
    if (mysql_stmt_errno(stmt) == 2056) {
        // Re-prepare statement and retry
        mysql_stmt_close(stmt);
        stmt = mysql_stmt_init(conn);
        mysql_stmt_prepare(stmt, query, strlen(query));
        
        // Exponential backoff
        usleep(delay_ms * 1000);
        delay_ms *= 2;
        retry_count++;
    } else {
        // Other error, don't retry
        break;
    }
}

# Monitor prepared statements on server
mysqladmin extended-status | grep -i prepared

# Check process list for statement issues
SHOW PROCESSLIST;

# Enable general query log temporarily
SET GLOBAL general_log = 1;
SET GLOBAL log_output = 'TABLE';
SELECT * FROM mysql.general_log WHERE argument LIKE '%PREPARE%' OR argument LIKE '%EXECUTE%';

# Use performance schema for statement analysis
SELECT * FROM performance_schema.prepared_statements_instances;