GUAC-1512: Add absolute connection limit properties for MySQL/PostgreSQL.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/src/main/java/net/sourceforge/guacamole/net/auth/mysql/MySQLEnvironment.java

@@ -51,6 +51,12 @@ public class MySQLEnvironment extends JDBCEnvironment {
      */
     private static final int DEFAULT_PORT = 3306;
 
+    /**
+     * The default value for the maximum number of connections to be
+     * allowed to the Guacamole server overall.
+     */
+    private final int ABSOLUTE_MAX_CONNECTIONS = 0;
+
     /**
      * The default value for the default maximum number of connections to be
      * allowed per user to any one connection. Note that, as long as the
@@ -164,6 +170,13 @@ public class MySQLEnvironment extends JDBCEnvironment {
 
     }
 
+    @Override
+    public int getAbsoluteMaxConnections() throws GuacamoleException {
+        return getProperty(MySQLGuacamoleProperties.MYSQL_ABSOLUTE_MAX_CONNECTIONS,
+            ABSOLUTE_MAX_CONNECTIONS
+        );
+    }
+
     @Override
     public int getDefaultMaxConnections() throws GuacamoleException {
         return getProperty(

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/src/main/java/net/sourceforge/guacamole/net/auth/mysql/MySQLGuacamoleProperties.java

@@ -115,6 +115,19 @@ public class MySQLGuacamoleProperties {
 
     };
 
+    /**
+     * The maximum number of concurrent connections to allow overall. Zero
+     * denotes unlimited.
+     */
+    public static final IntegerGuacamoleProperty
+            MYSQL_ABSOLUTE_MAX_CONNECTIONS =
+            new IntegerGuacamoleProperty() {
+
+        @Override
+        public String getName() { return "mysql-absolute-max-connections"; }
+
+    };
+
     /**
      * The maximum number of concurrent connections to allow to any one
      * connection. Zero denotes unlimited.