Add Log4j2 benchmark tool

- Configurable thread count, duration, message size
- Multiple logging configurations: sync-immediate, sync-buffered
- AsyncLogger variants: 1k, 4k, 10k, 1m ring buffer sizes
- AsyncAppender variants: 1k, 4k, 10k, 1m buffer sizes
- Subprocess isolation for proper async logger initialization
- Cache dropping between tests for accurate benchmarks
- CSV output support

10 files changed, 163 insertions, 0 deletions

diff --git a/src/main/resources/log4j2-async-10k.xml b/src/main/resources/log4j2-async-10k.xml
new file mode 100644
index 0000000..b2d26a9
--- /dev/null
+++ b/src/main/resources/log4j2-async-10k.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="false" bufferSize="8192">
+            <PatternLayout pattern="[ASYNC-10K] %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+    </Appenders>
+    <Loggers>
+        <AsyncLogger name="bench" level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </AsyncLogger>
+        <Root level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </Root>
+    </Loggers>
+    <Properties>
+        <Property name="log4j2.asyncLoggerRingBufferSize">10240</Property>
+    </Properties>
+</Configuration>
diff --git a/src/main/resources/log4j2-async-1k.xml b/src/main/resources/log4j2-async-1k.xml
new file mode 100644
index 0000000..66389fe
--- /dev/null
+++ b/src/main/resources/log4j2-async-1k.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="false" bufferSize="8192">
+            <PatternLayout pattern="[ASYNC-1K] %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+    </Appenders>
+    <Loggers>
+        <AsyncLogger name="bench" level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </AsyncLogger>
+        <Root level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </Root>
+    </Loggers>
+    <Properties>
+        <Property name="log4j2.asyncLoggerRingBufferSize">1024</Property>
+    </Properties>
+</Configuration>
diff --git a/src/main/resources/log4j2-async-1m.xml b/src/main/resources/log4j2-async-1m.xml
new file mode 100644
index 0000000..596d3d5
--- /dev/null
+++ b/src/main/resources/log4j2-async-1m.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="true">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+    </Appenders>
+    <Loggers>
+        <AsyncLogger name="bench" level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </AsyncLogger>
+        <Root level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </Root>
+    </Loggers>
+</Configuration>
diff --git a/src/main/resources/log4j2-async-4k.xml b/src/main/resources/log4j2-async-4k.xml
new file mode 100644
index 0000000..9e51895
--- /dev/null
+++ b/src/main/resources/log4j2-async-4k.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="false" bufferSize="8192">
+            <PatternLayout pattern="[ASYNC-4K] %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+    </Appenders>
+    <Loggers>
+        <AsyncLogger name="bench" level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </AsyncLogger>
+        <Root level="info" includeLocation="false">
+            <AppenderRef ref="File"/>
+        </Root>
+    </Loggers>
+    <Properties>
+        <Property name="log4j2.asyncLoggerRingBufferSize">4096</Property>
+    </Properties>
+</Configuration>
diff --git a/src/main/resources/log4j2-asyncapp-10k.xml b/src/main/resources/log4j2-asyncapp-10k.xml
new file mode 100644
index 0000000..40db21e
--- /dev/null
+++ b/src/main/resources/log4j2-asyncapp-10k.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="true">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+        <Async name="Async" bufferSize="10240">
+            <AppenderRef ref="File"/>
+        </Async>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="Async"/>
+        </Root>
+    </Loggers>
+</Configuration>
diff --git a/src/main/resources/log4j2-asyncapp-1k.xml b/src/main/resources/log4j2-asyncapp-1k.xml
new file mode 100644
index 0000000..ad43e23
--- /dev/null
+++ b/src/main/resources/log4j2-asyncapp-1k.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="true">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+        <Async name="Async" bufferSize="1024">
+            <AppenderRef ref="File"/>
+        </Async>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="Async"/>
+        </Root>
+    </Loggers>
+</Configuration>
diff --git a/src/main/resources/log4j2-asyncapp-1m.xml b/src/main/resources/log4j2-asyncapp-1m.xml
new file mode 100644
index 0000000..7b5e1bb
--- /dev/null
+++ b/src/main/resources/log4j2-asyncapp-1m.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="true">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+        <Async name="Async" bufferSize="1048576">
+            <AppenderRef ref="File"/>
+        </Async>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="Async"/>
+        </Root>
+    </Loggers>
+</Configuration>
diff --git a/src/main/resources/log4j2-asyncapp-4k.xml b/src/main/resources/log4j2-asyncapp-4k.xml
new file mode 100644
index 0000000..af4a2f2
--- /dev/null
+++ b/src/main/resources/log4j2-asyncapp-4k.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="true">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+        <Async name="Async" bufferSize="4096">
+            <AppenderRef ref="File"/>
+        </Async>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="Async"/>
+        </Root>
+    </Loggers>
+</Configuration>
diff --git a/src/main/resources/log4j2-sync-buffered.xml b/src/main/resources/log4j2-sync-buffered.xml
new file mode 100644
index 0000000..ed143ab
--- /dev/null
+++ b/src/main/resources/log4j2-sync-buffered.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="false" bufferSize="8192">
+            <PatternLayout pattern="[SYNC-BUF] %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="File"/>
+        </Root>
+    </Loggers>
+</Configuration>
diff --git a/src/main/resources/log4j2-sync-immediate.xml b/src/main/resources/log4j2-sync-immediate.xml
new file mode 100644
index 0000000..25d5303
--- /dev/null
+++ b/src/main/resources/log4j2-sync-immediate.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <File name="File" fileName="target/bench.log" immediateFlush="true">
+            <PatternLayout pattern="[SYNC-IMM] %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </File>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="File"/>
+        </Root>
+    </Loggers>
+</Configuration>