| /* |
| * 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. |
| */ |
| |
| #ifndef _LOG4CXX_NET_XML_SOCKET_APPENDER_H |
| #define _LOG4CXX_NET_XML_SOCKET_APPENDER_H |
| |
| #include <log4cxx/net/socketappenderskeleton.h> |
| #include <log4cxx/helpers/writer.h> |
| |
| namespace log4cxx |
| { |
| namespace net |
| { |
| |
| /** |
| Sends {@link log4cxx::spi::LoggingEvent LoggingEvent} objects in XML format |
| to a remote a log server, usually a XMLSocketNode. |
| |
| <p>The XMLSocketAppender has the following properties: |
| |
| - If sent to a XMLSocketNode, remote logging |
| is non-intrusive as far as the log event is concerned. In other |
| words, the event will be logged with the same time stamp, {@link |
| NDC NDC}, location info as if it were logged locally by |
| the client. |
| |
| - XMLSocketAppenders use exclusively an XMLLayout. They ship an |
| XML stream representing a {@link spi::LoggingEvent LoggingEvent} object |
| to the server side. |
| |
| - Remote logging uses the TCP protocol. Consequently, if |
| the server is reachable, then log events will eventually arrive |
| at the server. |
| |
| - If the remote server is down, the logging requests are |
| simply dropped. However, if and when the server comes back up, |
| then event transmission is resumed transparently. This |
| transparent reconneciton is performed by a <em>connector</em> |
| thread which periodically attempts to connect to the server. |
| |
| - Logging events are automatically <em>buffered</em> by the |
| native TCP implementation. This means that if the link to server |
| is slow but still faster than the rate of (log) event production |
| by the client, the client will not be affected by the slow |
| network connection. However, if the network connection is slower |
| then the rate of event production, then the client can only |
| progress at the network rate. In particular, if the network link |
| to the the server is down, the client will be blocked. |
| @n @n On the other hand, if the network link is up, but the server |
| is down, the client will not be blocked when making log requests |
| but the log events will be lost due to server unavailability. |
| |
| - Even if an <code>XMLSocketAppender</code> is no longer |
| attached to any logger, it will not be destroyed in |
| the presence of a connector thread. A connector thread exists |
| only if the connection to the server is down. To avoid this |
| destruction problem, you should #close the the |
| <code>XMLSocketAppender</code> explicitly. See also next item. |
| @n @n Long lived applications which create/destroy many |
| <code>XMLSocketAppender</code> instances should be aware of this |
| destruction problem. Most other applications can safely |
| ignore it. |
| |
| - If the application hosting the <code>XMLSocketAppender</code> |
| exits before the <code>XMLSocketAppender</code> is closed either |
| explicitly or subsequent to destruction, then there might |
| be untransmitted data in the pipe which might be lost. |
| @n @n To avoid lost data, it is usually sufficient to |
| #close the <code>XMLSocketAppender</code> either explicitly or by |
| calling the LogManager#shutdown method |
| before exiting the application. |
| */ |
| |
| class LOG4CXX_EXPORT XMLSocketAppender : public SocketAppenderSkeleton |
| { |
| public: |
| /** |
| The default port number of remote logging server (4560). |
| */ |
| static int DEFAULT_PORT; |
| |
| /** |
| The default reconnection delay (30000 milliseconds or 30 seconds). |
| */ |
| static int DEFAULT_RECONNECTION_DELAY; |
| |
| /** |
| An event XML stream cannot exceed 1024 bytes. |
| */ |
| static const int MAX_EVENT_LEN; |
| |
| DECLARE_LOG4CXX_OBJECT(XMLSocketAppender) |
| BEGIN_LOG4CXX_CAST_MAP() |
| LOG4CXX_CAST_ENTRY(XMLSocketAppender) |
| LOG4CXX_CAST_ENTRY_CHAIN(AppenderSkeleton) |
| END_LOG4CXX_CAST_MAP() |
| |
| XMLSocketAppender(); |
| ~XMLSocketAppender(); |
| |
| /** |
| Connects to remote server at <code>address</code> and <code>port</code>. |
| */ |
| XMLSocketAppender(helpers::InetAddressPtr address, int port); |
| |
| /** |
| Connects to remote server at <code>host</code> and <code>port</code>. |
| */ |
| XMLSocketAppender(const LogString& host, int port); |
| |
| |
| protected: |
| virtual void setSocket(log4cxx::helpers::SocketPtr& socket, log4cxx::helpers::Pool& p); |
| |
| virtual void cleanUp(log4cxx::helpers::Pool& p); |
| |
| virtual int getDefaultDelay() const; |
| |
| virtual int getDefaultPort() const; |
| |
| void append(const spi::LoggingEventPtr& event, log4cxx::helpers::Pool& pool); |
| |
| private: |
| log4cxx::helpers::WriterPtr writer; |
| // prevent copy and assignment statements |
| XMLSocketAppender(const XMLSocketAppender&); |
| XMLSocketAppender& operator=(const XMLSocketAppender&); |
| }; // class XMLSocketAppender |
| |
| LOG4CXX_PTR_DEF(XMLSocketAppender); |
| |
| } // namespace net |
| } // namespace log4cxx |
| |
| #endif // _LOG4CXX_NET_XML_SOCKET_APPENDER_H |
| |