log4j1-appenders

This package contains useful Log4j appenders. Currently, it contains:

ClpIrFileAppender - Used to compress log events using CLP's IR stream format, allowing users to achieve higher compression than general-purpose compressors while the logs are being generated.
AbstractBufferedRollingFileAppender - An abstract class which enforces an opinionated workflow, skeleton interfaces and hooks optimized towards buffered rolling file appender implementations with remote persistent storage. In addition, the abstract class implements verbosity-aware hard+soft timeout based log freshness policy.
AbstractClpirBufferedRollingFileAppender - Provides size-based file rollover, log freshness guarantee and streaming compression offered in ClpIrFileAppender.

Usage

`ClpIrFileAppender`

Add the package and its dependencies to the dependencies section of your your pom.xml:

<dependencies>
  <!-- The appenders -->
  <dependency>
    <groupId>com.yscope.logging</groupId>
    <artifactId>log4j1-appenders</artifactId>
    <version>0.0.0</version>
  </dependency>
  <!-- Packages that log4j1-appenders depends on -->
  <dependency>
    <groupId>com.github.luben</groupId>
    <artifactId>zstd-jni</artifactId>
    <version>1.5.2-1</version>
  </dependency>
  <dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
    <scope>provided</scope>
  </dependency>
</dependencies>

Add the appender to your log4j configuration file. Here is a sample log4j.properties file:

 log4j.rootLogger=INFO, clpir
 
 log4j.appender.clpir=com.yscope.logging.log4j1.ClpIrFileAppender
 log4j.appender.clpir.layout=org.apache.log4j.EnhancedPatternLayout
 # NOTE:
 # 1. This appender doesn't require a date conversion pattern in the 
 #    conversion pattern. This is because the CLP appender stores the 
 #    timestamp separately from the message. CLP's IR decoders will allow 
 #    users to specify their desired timestamp format when decoding the logs.
 # 2. If a date conversion pattern is added, it will be removed from the 
 #    conversion pattern. This may result in an ugly conversion pattern since 
 #    the spaces around the date pattern are not removed.
 log4j.appender.clpir.layout.ConversionPattern=%p [%c{1}] %m%n
 log4j.appender.clpir.file=logs.clp.zst
 # Use CLP's four-byte encoding for lower memory usage at the cost of some
 # compression ratio
 log4j.appender.clpir.useFourByteEncoding=true
 # closeFrameOnFlush:
 # - true: any data buffered by the compressor is immediately flushed to disk;
 #   frequent flushes may lower compression ratio significantly
 # - false: any compressed data that is ready for writing will be flushed to disk
 log4j.appender.clpir.closeFrameOnFlush=false
 # compressionLevel: Higher compression levels may increase compression ratio
 # but will slow down compression. Valid compression levels are 1-19.
 log4j.appender.clpir.compressionLevel=3

`AbstractClpIrBufferedRollingFileAppender`

To use class, we expect user to implement at minimum the sync() method to perform file upload to remote persistent store.

Providing Feedback

You can use GitHub issues to report a bug or request a feature.

Building

Build and test
```
mvn package
```

Build without any extras

mvn package -DskipTests -Dmaven.javadoc.skip=true -Dmaven.source.skip

Testing

mvn test

y-scope/log4j1-appenders