Using Map.of in a ContextDataProvider implementation throws UOE

[slinkydeveloper]

Description

I'm using logj2 with a custom ContextDataProvider, and then using the aws lambda appender. My ContextDataProvider implementation uses Map.of methods from JDK to create cheap immutable maps, but apparently that doesn't work and throws UOE.

In the stacktrace it's shown that a method down the stack invokes ImmutableCollections.AbstractImmutableMap::clear, which throws UOE. Interesting enough, in many online examples they use Collections.emptyMap() for the empty map, which doesn't throw UOE on clear.

What puzzles me though is that I wasn't able to reproduce this issue with the log4j2-core console appender. Is the amazon appender doing something strange, or is this a bug of log4j2-core?

Configuration

Version: 2.22.0

Operating system: Linux

JDK: 21 (amazon)

Logs

2023-12-15T11:26:15.337000+00:00  WARN StatusConsoleListener org.apache.logging.log4j.spi.AbstractLogger caught java.lang.UnsupportedOperationException logging ReusableSimpleMessage: Incremented counter!
2023-12-15T11:26:15.338000+00:00  java.lang.UnsupportedOperationException
2023-12-15T11:26:15.338000+00:00  at java.base/java.util.ImmutableCollections.uoe(Unknown Source)
2023-12-15T11:26:15.338000+00:00  at java.base/java.util.ImmutableCollections$AbstractImmutableMap.clear(Unknown Source)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.core.impl.JdkMapAdapterStringMap.clear(JdkMapAdapterStringMap.java:122)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.core.impl.MutableLogEvent.clear(MutableLogEvent.java:143)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.core.impl.ReusableLogEventFactory.release(ReusableLogEventFactory.java:141)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:578)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.core.config.AwaitCompletionReliabilityStrategy.log(AwaitCompletionReliabilityStrategy.java:92)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.core.Logger.log(Logger.java:169)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.spi.AbstractLogger.tryLogMessage(AbstractLogger.java:2933)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.spi.AbstractLogger.logMessageTrackRecursion(AbstractLogger.java:2886)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.spi.AbstractLogger.logMessageSafely(AbstractLogger.java:2868)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.spi.AbstractLogger.logMessage(AbstractLogger.java:2647)
2023-12-15T11:26:15.338000+00:00  at org.apache.logging.log4j.spi.AbstractLogger.logIfEnabled(AbstractLogger.java:2594)
2023-12-15T11:26:15.339000+00:00  at org.apache.logging.log4j.spi.AbstractLogger.info(AbstractLogger.java:1597)
2023-12-15T11:26:15.339000+00:00  at dev.restate.sdk.examples.Greeter.greet(Greeter.kt:31)
[... My application stacktrace ...]
2023-12-15T11:26:15.340000+00:00  at dev.restate.sdk.lambda.BaseRestateLambdaHandler.handleRequest(BaseRestateLambdaHandler.java:28)
2023-12-15T11:26:15.340000+00:00  at com.amazonaws.services.lambda.runtime.api.client.EventHandlerLoader$PojoHandlerAsStreamHandler.handleRequest(EventHandlerLoader.java:202)
2023-12-15T11:26:15.340000+00:00  at com.amazonaws.services.lambda.runtime.api.client.EventHandlerLoader$2.call(EventHandlerLoader.java:905)
2023-12-15T11:26:15.340000+00:00  at com.amazonaws.services.lambda.runtime.api.client.AWSLambda.startRuntime(AWSLambda.java:245)
2023-12-15T11:26:15.340000+00:00  at com.amazonaws.services.lambda.runtime.api.client.AWSLambda.startRuntime(AWSLambda.java:197)
2023-12-15T11:26:15.340000+00:00  at com.amazonaws.services.lambda.runtime.api.client.AWSLambda.main(AWSLambda.java:187)

[slinkydeveloper]

FYI the aws lambda appender has probably nothing to do with this issue anyway, as i've found out here #2099

[ppkarwasz]

@slinkydeveloper,

Thanks for reporting this issue. Our Java Map to StringMap didn't check if the wrapped map is immutable and didn't mark it as frozen.

This should be fixed in the next release.