GUACAMOLE-102: Initial addition of connection weight to JDBC authentication extension

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/JDBCEnvironment.java

@@ -81,6 +81,17 @@ public abstract class JDBCEnvironment extends LocalEnvironment {
      *     If an error occurs while retrieving the property.
      */
     public abstract int getDefaultMaxConnections() throws GuacamoleException;
+
+    /**
+     * Returns the connection weight for the purpose of WRR calculation
+     *
+     * @return
+     *     The weight of the connection.
+     *
+     * @throws GuacamoleException  
+     *     If an error occurs while retrieving the property.
+     */
+    public abstract int getConnectionWeight() throws GuacamoleException;
     
     /**
      * Returns the default maximum number of concurrent connections to allow to 

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/connection/ConnectionModel.java

@@ -54,6 +54,13 @@ public class ConnectionModel extends ChildObjectModel {
      */
     private Integer maxConnectionsPerUser;
 
+    /**
+     * The weight of the connection for the purposes of calculating
+     * WRR algorithm.  null indicates nothing has been set, -1 indicates
+     * the system is unavailable.
+     */
+    private Integer connectionWeight;
+
     /**
      * The identifiers of all readable sharing profiles associated with this
      * connection.
@@ -164,6 +171,29 @@ public class ConnectionModel extends ChildObjectModel {
         return maxConnectionsPerUser;
     }
 
+    /**
+     * Sets the connection weight.
+     *
+     * @param connectionWeight
+     *     The weight of the connection.  null is acceptable, -1 indicates the
+     *     connection should not be used.
+     */
+    public void setConnectionWeight(Integer connectionWeight) {
+        this.connectionWeight = connectionWeight;
+    }
+
+    /**
+     * Returns the connection weight used in calculating the
+     * WRR algorithm.
+     *
+     * @return
+     *     The connection weight.  Null indicates no weight has been set,
+     *     -1 indicates that the system is unavailable.
+     */
+    public Integer getConnectionWeight() {
+        return connectionWeight;
+    }
+
     /**
      * Sets the maximum number of connections that can be established to this
      * connection concurrently by any one user.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/connection/ModeledConnection.java

@@ -116,6 +116,11 @@ public class ModeledConnection extends ModeledChildDirectoryObject<ConnectionMod
      */
     public static final String MAX_CONNECTIONS_PER_USER_NAME = "max-connections-per-user";
 
+    /**
+     * The connection weight for the WRR algorithm.
+     */
+    public static final String CONNECTION_WEIGHT = "connection-weight";
+
     /**
      * All attributes related to restricting user accounts, within a logical
      * form.
@@ -265,6 +270,9 @@ public class ModeledConnection extends ModeledChildDirectoryObject<ConnectionMod
             }
         }
 
+        // Set connection weight
+        attributes.put(CONNECTION_WEIGHT, NumericField.format(getModel().getConnectionWeight()));
+
         return attributes;
     }
 
@@ -310,6 +318,13 @@ public class ModeledConnection extends ModeledChildDirectoryObject<ConnectionMod
         else
             getModel().setProxyEncryptionMethod(null);
 
+        // Translate connection weight attribute
+        try { getModel().setConnectionWeight(NumericField.parse(attributes.get(CONNECTION_WEIGHT))); }
+        catch (NumberFormatException e) {
+            logger.warn("Not setting the connection weight: {}", e.getMessage());
+            logger.debug("Unable to parse numeric attribute.", e);
+        }
+
     }
 
     /**
@@ -394,6 +409,25 @@ public class ModeledConnection extends ModeledChildDirectoryObject<ConnectionMod
             encryptionMethod != null ? encryptionMethod : defaultConfig.getEncryptionMethod()
         );
 
+    /** 
+     * Returns the weight of the connection, or the default.
+     *  
+     * @return
+     *     The weight of the connection.
+     *  
+     * @throws GuacamoleException
+     *     If an error occurs while parsing the concurrency limit properties
+     *     specified within guacamole.properties.
+     */
+    public int getConnectionWeight() throws GuacamoleException {
+
+        // Pull default from environment if weight is unset
+        Integer value = getModel().getConnectionWeight();
+        if (value == null)
+            return environment.getDefaultConnectionWeight();
+
+        // Otherwise use defined value
+        return value;
     }
 
 }

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/tunnel/RestrictedGuacamoleTunnelService.java

@@ -33,6 +33,8 @@ import org.apache.guacamole.GuacamoleResourceConflictException;
 import org.apache.guacamole.auth.jdbc.JDBCEnvironment;
 import org.apache.guacamole.auth.jdbc.connectiongroup.ModeledConnectionGroup;
 import org.apache.guacamole.auth.jdbc.user.RemoteAuthenticatedUser;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 
 /**
@@ -44,6 +46,11 @@ import org.apache.guacamole.auth.jdbc.user.RemoteAuthenticatedUser;
 public class RestrictedGuacamoleTunnelService
     extends AbstractGuacamoleTunnelService {
 
+    /**
+     * Logger for this class.
+     */
+    private static final Logger logger = LoggerFactory.getLogger(RestrictedGuacamoleTunnelService.class);
+
     /**
      * The environment of the Guacamole server.
      */
@@ -166,20 +173,24 @@ public class RestrictedGuacamoleTunnelService
     protected ModeledConnection acquire(RemoteAuthenticatedUser user,
             List<ModeledConnection> connections) throws GuacamoleException {
 
+        logger.trace("Attempting to acquire a connection...");
         // Do not acquire connection unless within overall limits
         if (!tryIncrement(totalActiveConnections, environment.getAbsoluteMaxConnections()))
             throw new GuacamoleResourceConflictException("Cannot connect. Overall maximum connections reached.");
 
         // Get username
         String username = user.getIdentifier();
+        logger.trace("Username is: {}", username);
 
+        logger.trace("Sorting {} connections.", connections.size());
         // Sort connections in ascending order of usage
         ModeledConnection[] sortedConnections = connections.toArray(new ModeledConnection[connections.size()]);
         Arrays.sort(sortedConnections, new Comparator<ModeledConnection>() {
 
             @Override
             public int compare(ModeledConnection a, ModeledConnection b) {
-
+                
+                logger.trace("Comparing {} to {}.", a.getName(), b.getName());
                 return getActiveConnections(a).size()
                      - getActiveConnections(b).size();
 
@@ -194,15 +205,18 @@ public class RestrictedGuacamoleTunnelService
         for (ModeledConnection connection : sortedConnections) {
 
             // Attempt to aquire connection according to per-user limits
+            logger.trace("Trying to grab a seat on this train: {}", connection.getName());
             Seat seat = new Seat(username, connection.getIdentifier());
             if (tryAdd(activeSeats, seat,
                     connection.getMaxConnectionsPerUser())) {
 
+                logger.trace("Got a seat, trying to get the connection...");
                 // Attempt to aquire connection according to overall limits
                 if (tryAdd(activeConnections, connection.getIdentifier(),
                         connection.getMaxConnections()))
                     return connection;
 
+                logger.trace("Uh-oh, failed to get the connection...");
                 // Acquire failed - retry with next connection
                 activeSeats.remove(seat);
 
@@ -213,6 +227,7 @@ public class RestrictedGuacamoleTunnelService
 
         }
 
+        logger.trace("Well, we failed to get a seat at all...");
         // Acquire failed
         totalActiveConnections.decrementAndGet();
 

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/schema/001-create-schema.sql

@@ -34,7 +34,6 @@ CREATE TABLE `guacamole_connection_group` (
   `max_connections_per_user` int(11),
   `enable_session_affinity`  boolean NOT NULL DEFAULT 0,
 
-
   PRIMARY KEY (`connection_group_id`),
   UNIQUE KEY `connection_group_name_parent` (`connection_group_name`, `parent_id`),
 
@@ -65,6 +64,10 @@ CREATE TABLE `guacamole_connection` (
   -- Concurrency limits
   `max_connections`          int(11),
   `max_connections_per_user` int(11),
+  
+  -- Connection weight
+  `connection_weight`        int(11),
+
 
   PRIMARY KEY (`connection_id`),
   UNIQUE KEY `connection_name_parent` (`connection_name`, `parent_id`),

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/schema/upgrade/upgrade-pre-0.9.12.sql

@@ -0,0 +1,25 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+--
+
+--
+-- Add per-user password set date
+--
+
+ALTER TABLE guacamole_connection
+    ADD COLUMN connection_weight int(11);

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/src/main/java/org/apache/guacamole/auth/mysql/MySQLEnvironment.java

@@ -87,6 +87,11 @@ public class MySQLEnvironment extends JDBCEnvironment {
      */
     private int DEFAULT_MAX_CONNECTIONS = 0;
 
+    /**
+     * The default value for the connection weight for a connection in
+     * a balancing group.
+    private int DEFAULT_CONNECTION_WEIGHT = 0;
+
     /**
      * The default value for the default maximum number of connections to be
      * allowed to any one connection group. Note that, as long as the legacy
@@ -194,6 +199,14 @@ public class MySQLEnvironment extends JDBCEnvironment {
         );
     }
 
+    @Override
+    public int getDefaultConnectionWeight() throws GuacamoleException {
+        return getProperty(
+            MySQLGuacamoleProperties.MYSQL_DEFAULT_CONNECTION_WEIGHT,
+            DEFAULT_CONNECTION_WEIGHT
+        );
+    }
+
     @Override
     public int getDefaultMaxGroupConnections() throws GuacamoleException {
         return getProperty(

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/src/main/java/org/apache/guacamole/auth/mysql/MySQLGuacamoleProperties.java

@@ -174,6 +174,18 @@ public class MySQLGuacamoleProperties {
 
     };
 
+    /**
+     * The connection weight for connections in balancing groups.
+     */
+    public static final IntegerGuacamoleProperty
+            MYSQL_DEFAULT_CONNECTION_WEIGHT =
+            new IntegerGuacamoleProperty() {
+       
+        @Overide
+        public String getName() { return "mysql-default-connection-weight"; }
+
+    };
+
     /**
      * The maximum number of concurrent connections to allow to any one
      * connection group by an individual user. Zero denotes

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/apache/guacamole/auth/postgresql/PostgreSQLEnvironment.java

@@ -87,6 +87,11 @@ public class PostgreSQLEnvironment extends JDBCEnvironment {
      */
     private int DEFAULT_MAX_CONNECTIONS = 0;
 
+    /**
+     * The default value for the connection weight for a connection in
+     * a balancing group.
+    private int DEFAULT_CONNECTION_WEIGHT = 0;
+
     /**
      * The default value for the default maximum number of connections to be
      * allowed to any one connection group. Note that, as long as the legacy
@@ -194,6 +199,14 @@ public class PostgreSQLEnvironment extends JDBCEnvironment {
         );
     }
 
+    @Override
+    public int getDefaultConnectionWeight() throws GuacamoleException {
+        return getProperty(
+            PostgreSQLGuacamoleProperties.POSTGRESQL_DEFAULT_CONNECTION_WEIGHT,
+            DEFAULT_CONNECTION_WEIGHT
+        );
+    }
+
     @Override
     public int getDefaultMaxGroupConnections() throws GuacamoleException {
         return getProperty(

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/apache/guacamole/auth/postgresql/PostgreSQLGuacamoleProperties.java

@@ -157,6 +157,15 @@ public class PostgreSQLGuacamoleProperties {
 
     };
 
+    public static final IntegerGuacamoleProperty
+            POSTGRESQL_DEFAULT_CONNECTION_WEIGHT =
+            new IntegerGuacamoleProperty() {
+
+        @Override
+        public String getName() { return "postgresql-default-connection-weight"; }
+
+    };
+
     /**
      * The maximum number of concurrent connections to allow to any one
      * connection group. Zero denotes unlimited.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/resources/org/apache/guacamole/auth/jdbc/connection/ConnectionMapper.xml

@@ -37,6 +37,7 @@
         <result column="proxy_port"               property="proxyPort"             jdbcType="INTEGER"/>
         <result column="proxy_encryption_method"  property="proxyEncryptionMethod" jdbcType="VARCHAR"
                 javaType="org.apache.guacamole.net.auth.GuacamoleProxyConfiguration$EncryptionMethod"/>
+        <result column="connection_weight"        property="connectionWeight"      jdbcType="INTEGER"/>
 
         <!-- Associated sharing profiles -->
         <collection property="sharingProfileIdentifiers" resultSet="sharingProfiles" ofType="java.lang.String"
@@ -95,7 +96,8 @@
             max_connections_per_user,
             proxy_hostname,
             proxy_port,
-            proxy_encryption_method
+            proxy_encryption_method,
+            connection_weight
         FROM guacamole_connection
         WHERE connection_id IN
             <foreach collection="identifiers" item="identifier"
@@ -126,7 +128,8 @@
             max_connections_per_user,
             proxy_hostname,
             proxy_port,
-            proxy_encryption_method
+            proxy_encryption_method,
+            connection_weight
         FROM guacamole_connection
         JOIN guacamole_connection_permission ON guacamole_connection_permission.connection_id = guacamole_connection.connection_id
         WHERE guacamole_connection.connection_id IN
@@ -162,7 +165,8 @@
             max_connections_per_user,
             proxy_hostname,
             proxy_port,
-            proxy_encryption_method
+            proxy_encryption_method,
+            connection_weight
         FROM guacamole_connection
         WHERE 
             <if test="parentIdentifier != null">parent_id = #{parentIdentifier,jdbcType=INTEGER}::integer</if>
@@ -189,7 +193,8 @@
             max_connections_per_user,
             proxy_hostname,
             proxy_port,
-            proxy_encryption_method
+            proxy_encryption_method,
+            connection_weight
         )
         VALUES (
             #{object.name,jdbcType=VARCHAR},
@@ -199,7 +204,8 @@
             #{object.maxConnectionsPerUser,jdbcType=INTEGER},
             #{object.proxyHostname,jdbcType=VARCHAR},
             #{object.proxyPort,jdbcType=INTEGER},
-            #{object.proxyEncryptionMethod,jdbcType=VARCHAR}::guacamole_proxy_encryption_method
+            #{object.proxyEncryptionMethod,jdbcType=VARCHAR}::guacamole_proxy_encryption_method,
+            #{object.connectionWeight,jdbcType=INTEGER}
         )
 
     </insert>
@@ -214,7 +220,8 @@
             max_connections_per_user = #{object.maxConnectionsPerUser,jdbcType=INTEGER},
             proxy_hostname           = #{object.proxyHostname,jdbcType=VARCHAR},
             proxy_port               = #{object.proxyPort,jdbcType=INTEGER},
-            proxy_encryption_method  = #{object.proxyEncryptionMethod,jdbcType=VARCHAR}::guacamole_proxy_encryption_method
+            proxy_encryption_method  = #{object.proxyEncryptionMethod,jdbcType=VARCHAR}::guacamole_proxy_encryption_method,
+            connection_weight        = #{object.connectionWeight,jdbcType=INTEGER}
         WHERE connection_id = #{object.objectID,jdbcType=INTEGER}::integer
     </update>