How do I enable DynamoDB Local Logging? - amazon-dynamodb

Question

More than often DynamoDB Local does not show descriptive error messages, in order to see internal errors you need to enable logging.
What are the steps to enable DynamoDB Local logging on the standard output?

Answer 1

Go to the directory that has the DynamoDBLocal.jar
Create a file called log4j2.xml with these contents:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
</Appenders>
<Loggers>
<Logger name="com.amazonaws.services.dynamodbv2.local" level="DEBUG">
<AppenderRef ref="Console"/>
</Logger>
<Logger name="com.amazonaws.services.dynamodbv2.local.shared.access.sqlite.SQLiteDBAccess" level="INFO">
<AppenderRef ref="Console"/>
</Logger>
<Root level="WARN">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
Remove the existing log4j2.xml from the jar
zip -d DynamoDBLocal.jar log4j2.xml
Add the created log4j2.xml to the jar
zip -u DynamoDBLocal.jar log4j2.xml
or simply edit the log4j2.xml in the DynamoDBLocal.jar using 7-Zip etc. and overwrite it with the xml above and skip the steps 2-4.

Answer 2

Change to the directory with DynamoDBLocal.jar
Create a new file called log4j.properties with the contents:
log4j.rootLogger=DEBUG, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=LOG%d %p [%c] - %m%n
Remove the existing log4j.properties files from the jar (there might be two)
zip -d DynamoDBLocal.jar log4j.properties
zip -d DynamoDBLocal.jar log4j.properties
Add the new properties file to the jar
zip -u DynamoDBLocal.jar log4j.properties
Source: https://gist.github.com/mdaley/aaf9b62d90f6817eb72a