Sends spi::LoggingEvent elements to a remote a log server, usually in XML format.

Here is an example configuration that writes JSON to the TCP input plugin of a fluent-bit log server running on the same system as the application:

XMLSocketAppender has the following properties:

• The event will be logged with the same time stamp, NDC, location info as if it were logged locally by the client.
• 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 connector thread which periodically attempts to connect to the server.
• Logging events are automatically buffered 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.
  
  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 XMLSocketAppender 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 XMLSocketAppender explicitly. See also next item.
  
  Long lived applications which create/destroy many XMLSocketAppender instances should be aware of this destruction problem. Most other applications can safely ignore it.
• If the application hosting the XMLSocketAppender exits before the XMLSocketAppender is closed either explicitly or subsequent to destruction, then there might be untransmitted data in the pipe which might be lost.
  
  To avoid lost data, it is usually sufficient to close the XMLSocketAppender either explicitly or by calling the LogManager::shutdown method before exiting the application.