Add support for total connections limit per vhost level

README.md

@@ -142,9 +142,10 @@ DATACENTER SET name | PRINT
 EXIT Exit the program gracefully.
 FARM (ADD name selector backend* | PARTITION name policy | DELETE name | PRINT) - Change farms
 HELP Print this help text.
-LIMIT (CONN_RATE_ALARM | CONN_RATE) (VHOST vhostName numberOfConnections | DEFAULT numberOfConnections) - Configure connection rate limits (normal or alarmonly) for incoming clients connections
+LIMIT (CONN_RATE_ALARM | CONN_RATE) (DEFAULT | VHOST vhostName) numberOfConnections - Configure connection rate limits (normal or alarmonly) for incoming clients connections
+LIMIT (TOTAL_CONN_ALARM | TOTAL_CONN) (DEFAULT | VHOST vhostName) numberOfConnections - Configure total connection limits or alarms for incoming client connections
 LIMIT (DATA_RATE_ALARM | DATA_RATE) (DEFAULT | VHOST vhostName) BytesPerSecond - Configure data rate limits or alarms for incoming client data
-LIMIT DISABLE (CONN_RATE_ALARM | CONN_RATE | DATA_RATE_ALARM | DATA_RATE) (VHOST vhostName | DEFAULT) - Disable configured limit thresholds
+LIMIT DISABLE (CONN_RATE_ALARM | CONN_RATE | TOTAL_CONN_ALARM | TOTAL_CONN | DATA_RATE_ALARM | DATA_RATE) (VHOST vhostName | DEFAULT) - Disable configured limit thresholds
 LIMIT PRINT [vhostName] - Print the configured default or specific connection rate limits for specified vhost
 LISTEN START port | START_SECURE port | STOP [port]
 LOG CONSOLE verbosity | FILE verbosity

docs/config.md

@@ -21,9 +21,10 @@ DATACENTER SET name | PRINT
 EXIT Exit the program gracefully.
 FARM (ADD name selector backend* | PARTITION name policy | DELETE name | PRINT) - Change farms
 HELP Print this help text.
-LIMIT (CONN_RATE_ALARM | CONN_RATE) (VHOST vhostName numberOfConnections | DEFAULT numberOfConnections) - Configure connection rate limits (normal or alarmonly) for incoming clients connections
+LIMIT (CONN_RATE_ALARM | CONN_RATE) (DEFAULT | VHOST vhostName) numberOfConnections - Configure connection rate limits (normal or alarmonly) for incoming clients connections
+LIMIT (TOTAL_CONN_ALARM | TOTAL_CONN) (DEFAULT | VHOST vhostName) numberOfConnections - Configure total connection limits or alarms for incoming client connections
 LIMIT (DATA_RATE_ALARM | DATA_RATE) (DEFAULT | VHOST vhostName) BytesPerSecond - Configure data rate limits or alarms for incoming client data
-LIMIT DISABLE (CONN_RATE_ALARM | CONN_RATE | DATA_RATE_ALARM | DATA_RATE) (VHOST vhostName | DEFAULT) - Disable configured limit thresholds
+LIMIT DISABLE (CONN_RATE_ALARM | CONN_RATE | TOTAL_CONN_ALARM | TOTAL_CONN | DATA_RATE_ALARM | DATA_RATE) (VHOST vhostName | DEFAULT) - Disable configured limit thresholds
 LIMIT PRINT [vhostName] - Print the configured default or specific connection rate limits for specified vhost
 LISTEN START port | START_SECURE port | STOP [port]
 LOG CONSOLE verbosity | FILE verbosity
@@ -142,6 +143,21 @@ Apply limit on allowed average number of connections per second for all the vhos
 #### LIMIT CONN_RATE VHOST vhostName numberOfConnections
 Apply limit on allowed average number of connections per second for specified vhost. The specific limit takes priority over the default limit for any vhost.
 
+#### LIMIT TOTAL_CONN_ALARM DEFAULT numberOfConnections
+
+Apply limit on allowed total number of connections in alarm only mode for all the vhosts. So whenever the in-coming connection violates the limit, the proxy will only emit log at warning level with AMQPPROX_CONNECTION_LIMIT as a substring and the relevant limiter details, instead of actively limiting any actual connection.
+
+#### LIMIT TOTAL_CONN_ALARM VHOST vhostName numberOfConnections
+
+Apply limit on allowed total number of connections in alarm only mode for specified vhost. The specific limit takes priority over the default limit for any vhost.
+
+#### LIMIT TOTAL_CONN DEFAULT numberOfConnections
+
+Apply limit on allowed total number of connections for all the vhosts. So whenever the in-coming connection violates the limit, the proxy will close that connection with appropriate error message and will not allow that client connection to connect to the broker.
+
+#### LIMIT TOTAL_CONN VHOST vhostName numberOfConnections
+Apply limit on allowed total number of connections for specified vhost. The specific limit takes priority over the default limit for any vhost.
+
 #### LIMIT DATA_RATE_ALARM DEFAULT BytesPerSecond
 
 Apply limit on allowed max bytes per second in alarm only mode for all the vhosts. So whenever any in-coming connection violates the data rate limit, the proxy will only emit log with Data Rate Alarm as a substring and the relevant limiter details, instead of actively limiting any data.
@@ -152,7 +168,8 @@ Apply limit on allowed max bytes per second in alarm only mode for specified vho
 
 #### LIMIT DATA_RATE DEFAULT numberOfConnections
 
-Apply limit on allowed max bytes per second for all the vhosts. So the data limit is enforced by counting the number of bytes read from the socket during each read operation, and pausing for one second before starting a read operation if the in-coming client connection violates the data.
+Apply limit on allowed max bytes per second for all the vhosts. So the data limit is enforced by counting the number of bytes read from the socket during each read operation, and pausing for one second before
+starting a read operation if the in-coming client connection violates the data.
 
 #### LIMIT DATA_RATE VHOST vhostName numberOfConnections
 Apply limit on allowed max bytes per second for specified vhost. The specific limit takes priority over the default limit for any vhost.
@@ -165,13 +182,21 @@ Remove default connection rate limit (allowed average number of connections per
 
 Remove specific connection rate limit (allowed average number of connections per second) for the specified vhost. The default limit will be applied to the specified vhost, if the default limit is already configured.
 
+#### LIMIT DISABLE TOTAL_CONN_ALARM DEFAULT numberOfConnections
+
+Remove default total connection limit (allowed total number of connections) in alarm only mode for all the vhosts.
+
+#### LIMIT DISABLE TOTAL_CONN VHOST vhostName numberOfConnections
+
+Remove specific total connection limit (allowed total number of connections) for the specified vhost. The default limit will be applied to the specified vhost, if the default limit is already configured.
+
 #### LIMIT DISABLE DATA_RATE_ALARM DEFAULT numberOfConnections
 
-Remove default data rate limit (allowed max bytes per second) in alarm only mode for all the vhosts.
+Remove default data rate limit (allowed average bytess per second) in alarm only mode for all the vhosts.
 
 #### LIMIT DISABLE DATA_RATE VHOST vhostName numberOfConnections
 
-Remove specific data rate limit (allowed max bytes per second) for the specified vhost. The default data limit will be applied to the specified vhost, if the default data limit is already configured.
+Remove specific data rate limit (allowed average bytes per second) for the specified vhost. The default data limit will be applied to the specified vhost, if the default data limit is already configured.
 
 #### LIMIT PRINT [vhostName]
 

libamqpprox/CMakeLists.txt

@@ -90,6 +90,7 @@ add_library(libamqpprox STATIC
     amqpprox_connectionlimiterinterface.cpp
     amqpprox_connectionlimitermanager.cpp
     amqpprox_fixedwindowconnectionratelimiter.cpp
+    amqpprox_totalconnectionlimiter.cpp
     amqpprox_limitcontrolcommand.cpp
     amqpprox_closeerror.cpp)
 

libamqpprox/amqpprox_connectionlimiterinterface.h

@@ -35,6 +35,12 @@ class ConnectionLimiterInterface {
      */
     virtual bool allowNewConnection() = 0;
 
+    /**
+     * \brief Called when an aquired connection is closed. Useful for changing
+     * the state of the limiter based on close connection event.
+     */
+    virtual void connectionClosed() {}
+
     // ACCESSORS
     /**
      * \return information about connection limiter as a string