logstash-logback-encoder-4.2

• #77 For TCP appender, resolve hostname on each reconnect
• #76 For TCP appender, add keepAlive functionality and improve error handling

logstash-logback-encoder-4.1

• Changed async and tcp appenders to use daemon threads by default, so that shutdown is not required for the jvm to exit properly.
• Changed async and tcp appenders to use BlockingWaitStrategy to consume less CPU resources when idle
• Added ability to configure wait strategy using simple string configuration
• Added custom SSL configuration support to all TCP appenders (using SSL support provided by logback)
  • SSL can now be used for AccessEvents

logstash-logback-encoder-4.0

Changes in 4.0:

• New CompositeJsonFormatter/Encoder/Layout were created to allow customizing the JSON output through the use of providers.
  • Each provider contained within the composite contributes to the JSON output.
  • All existing functionality was converted to individual providers
  • LogstashFormatter/Encoder/Layout were refactored to be just extensions of the composite concept that contain a pre-defined set of providers
• A new pattern-based provider was added. This provider allows usage of standard PatternLayout patterns within a JSON template. This allows much easier configuration, since you can layout your JSON event as a JSON string with embedded patterns for values.
• Added a new AsyncDisruptorAppender that is similar to logback's AsyncAppender, but uses an LMAX Disruptor RingBufferas the inter-thread data exchange mechanism (as opposed to a BlockingQueue used by the AsyncAppender)
  • Refactored the tcp appender to extend the AsyncDisruptorAppender so it can take advantage of the benefits of using a RingBuffer
• Add ability to define a prefix and suffix on the encoder/layouts that appear before/after the JSON output
• Lots of doc improvements

XML configuration is fully backwards compatible except for the following:

• The queueSize for the tcp appenders must now be a power of 2. Also, recommend you switch to using ringBufferSize instead of queueSize.
• The eventDelayLimit for the tcp appenders is no longer used (since the the appender will never block the logging thread)