1 | /*
|
---|
2 | * Licensed to the Apache Software Foundation (ASF) under one or more
|
---|
3 | * contributor license agreements. See the NOTICE file distributed with
|
---|
4 | * this work for additional information regarding copyright ownership.
|
---|
5 | * The ASF licenses this file to You under the Apache License, Version 2.0
|
---|
6 | * (the "License"); you may not use this file except in compliance with
|
---|
7 | * the License. You may obtain a copy of the License at
|
---|
8 | *
|
---|
9 | * http://www.apache.org/licenses/LICENSE-2.0
|
---|
10 | *
|
---|
11 | * Unless required by applicable law or agreed to in writing, software
|
---|
12 | * distributed under the License is distributed on an "AS IS" BASIS,
|
---|
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
---|
14 | * See the License for the specific language governing permissions and
|
---|
15 | * limitations under the License.
|
---|
16 | */
|
---|
17 |
|
---|
18 | #ifndef _LOG4CXX_NET_SOCKET_APPENDER_H
|
---|
19 | #define _LOG4CXX_NET_SOCKET_APPENDER_H
|
---|
20 |
|
---|
21 | #include <log4cxx/net/socketappenderskeleton.h>
|
---|
22 | #include <log4cxx/helpers/objectoutputstream.h>
|
---|
23 |
|
---|
24 | namespace log4cxx
|
---|
25 | {
|
---|
26 | namespace net
|
---|
27 | {
|
---|
28 |
|
---|
29 | /**
|
---|
30 | Sends {@link log4cxx::spi::LoggingEvent LoggingEvent} objects to a remote a log server,
|
---|
31 | usually Apache Chainsaw.
|
---|
32 |
|
---|
33 | <p>The SocketAppender has the following properties:
|
---|
34 |
|
---|
35 | - If sent to Apache Chainsaw, remote logging
|
---|
36 | is non-intrusive as far as the log event is concerned. In other
|
---|
37 | words, the event will be logged with the same time stamp, {@link
|
---|
38 | NDC NDC}, location info as if it were logged locally by
|
---|
39 | the client.
|
---|
40 |
|
---|
41 | - SocketAppenders do not use a layout. They ship a
|
---|
42 | serialized {@link log4cxx::spi::LoggingEvent LoggingEvent} object
|
---|
43 | to the server side.
|
---|
44 |
|
---|
45 | - Remote logging uses the TCP protocol. Consequently, if
|
---|
46 | the server is reachable, then log events will eventually arrive
|
---|
47 | at the server.
|
---|
48 |
|
---|
49 | - If the remote server is down, the logging requests are
|
---|
50 | simply dropped. However, if and when the server comes back up,
|
---|
51 | then event transmission is resumed transparently. This
|
---|
52 | transparent reconneciton is performed by a <em>connector</em>
|
---|
53 | thread which periodically attempts to connect to the server.
|
---|
54 |
|
---|
55 | - Logging events are automatically <em>buffered</em> by the
|
---|
56 | native TCP implementation. This means that if the link to server
|
---|
57 | is slow but still faster than the rate of (log) event production
|
---|
58 | by the client, the client will not be affected by the slow
|
---|
59 | network connection. However, if the network connection is slower
|
---|
60 | then the rate of event production, then the client can only
|
---|
61 | progress at the network rate. In particular, if the network link
|
---|
62 | to the the server is down, the client will be blocked.
|
---|
63 | @n @n On the other hand, if the network link is up, but the server
|
---|
64 | is down, the client will not be blocked when making log requests
|
---|
65 | but the log events will be lost due to server unavailability.
|
---|
66 |
|
---|
67 | - Even if a <code>SocketAppender</code> is no longer
|
---|
68 | attached to any logger, it will not be destroyed in
|
---|
69 | the presence of a connector thread. A connector thread exists
|
---|
70 | only if the connection to the server is down. To avoid this
|
---|
71 | destruction problem, you should #close the the
|
---|
72 | <code>SocketAppender</code> explicitly. See also next item.
|
---|
73 | @n @n Long lived applications which create/destroy many
|
---|
74 | <code>SocketAppender</code> instances should be aware of this
|
---|
75 | destruction problem. Most other applications can safely
|
---|
76 | ignore it.
|
---|
77 |
|
---|
78 | - If the application hosting the <code>SocketAppender</code>
|
---|
79 | exits before the <code>SocketAppender</code> is closed either
|
---|
80 | explicitly or subsequent to destruction, then there might
|
---|
81 | be untransmitted data in the pipe which might be lost.
|
---|
82 | @n @n To avoid lost data, it is usually sufficient to
|
---|
83 | #close the <code>SocketAppender</code> either explicitly or by
|
---|
84 | calling the LogManager#shutdown method
|
---|
85 | before exiting the application.
|
---|
86 | */
|
---|
87 |
|
---|
88 | class LOG4CXX_EXPORT SocketAppender : public SocketAppenderSkeleton
|
---|
89 | {
|
---|
90 | public:
|
---|
91 | /**
|
---|
92 | The default port number of remote logging server (4560).
|
---|
93 | */
|
---|
94 | static int DEFAULT_PORT;
|
---|
95 |
|
---|
96 | /**
|
---|
97 | The default reconnection delay (30000 milliseconds or 30 seconds).
|
---|
98 | */
|
---|
99 | static int DEFAULT_RECONNECTION_DELAY;
|
---|
100 |
|
---|
101 | DECLARE_LOG4CXX_OBJECT(SocketAppender)
|
---|
102 | BEGIN_LOG4CXX_CAST_MAP()
|
---|
103 | LOG4CXX_CAST_ENTRY(SocketAppender)
|
---|
104 | LOG4CXX_CAST_ENTRY_CHAIN(AppenderSkeleton)
|
---|
105 | END_LOG4CXX_CAST_MAP()
|
---|
106 |
|
---|
107 | SocketAppender();
|
---|
108 | ~SocketAppender();
|
---|
109 |
|
---|
110 | /**
|
---|
111 | Connects to remote server at <code>address</code> and <code>port</code>.
|
---|
112 | */
|
---|
113 | SocketAppender(helpers::InetAddressPtr& address, int port);
|
---|
114 |
|
---|
115 | /**
|
---|
116 | Connects to remote server at <code>host</code> and <code>port</code>.
|
---|
117 | */
|
---|
118 | SocketAppender(const LogString& host, int port);
|
---|
119 |
|
---|
120 |
|
---|
121 | protected:
|
---|
122 | virtual void setSocket(log4cxx::helpers::SocketPtr& socket, log4cxx::helpers::Pool& p);
|
---|
123 |
|
---|
124 | virtual void cleanUp(log4cxx::helpers::Pool& p);
|
---|
125 |
|
---|
126 | virtual int getDefaultDelay() const;
|
---|
127 |
|
---|
128 | virtual int getDefaultPort() const;
|
---|
129 |
|
---|
130 | void append(const spi::LoggingEventPtr& event, log4cxx::helpers::Pool& pool);
|
---|
131 |
|
---|
132 | private:
|
---|
133 | log4cxx::helpers::ObjectOutputStreamPtr oos;
|
---|
134 |
|
---|
135 | }; // class SocketAppender
|
---|
136 |
|
---|
137 | LOG4CXX_PTR_DEF(SocketAppender);
|
---|
138 |
|
---|
139 | } // namespace net
|
---|
140 | } // namespace log4cxx
|
---|
141 |
|
---|
142 | #endif // _LOG4CXX_NET_SOCKET_APPENDER_H
|
---|
143 |
|
---|