[KAFKA-4710] Logging trait breaking logging location information retrival by log4j

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.10.0.1
• Component/s: core
• Labels: log4j
• Assignee: Yuto Kawamura
• Reporter: Yuto Kawamura
• Created: 30/Jan/17 08:05
• Updated: 04/Dec/17 19:09

Description

We have in-house logging systems which sends problematic logs such as WARNs and ERRORs to the counting system.
The log4j appender is provided to send logs to the system. However, currently the most of logs written by Kafka broker are actually pointing the line of Logging trait since the most of them are written through calling Logging trait's helper method.

This happens when we add some modifiers such as %l to log4j appender pattern as well:

diff --git a/config/log4j.properties b/config/log4j.properties
index bf816e76d..e1b69e0da 100644
--- a/config/log4j.properties
+++ b/config/log4j.properties
@@ -23,7 +23,7 @@ log4j.appender.kafkaAppender=org.apache.log4j.DailyRollingFileAppender
 log4j.appender.kafkaAppender.DatePattern='.'yyyy-MM-dd-HH
 log4j.appender.kafkaAppender.File=${kafka.logs.dir}/server.log
 log4j.appender.kafkaAppender.layout=org.apache.log4j.PatternLayout
-log4j.appender.kafkaAppender.layout.ConversionPattern=[%d] %p %m (%c)%n
+log4j.appender.kafkaAppender.layout.ConversionPattern=[%d] %p %m (%c) - %l%n

[2017-01-30 15:48:28,333] INFO starting (kafka.server.KafkaServer) - kafka.utils.Logging$class.info(Logging.scala:68)
[2017-01-30 15:48:28,339] INFO Connecting to zookeeper on localhost:2181 (kafka.server.KafkaServer) - kafka.utils.Logging$class.info(Logging.scala:68)
[2017-01-30 15:48:34,908] FATAL Fatal error during KafkaServer startup. Prepare to shutdown (kafka.server.KafkaServer) - kafka.utils.Logging$class.fatal(Logging.scala:116)

As you can see, all locations are pointing somewhere of Logging.scala rather than the actual locations where logs are written.

Issue Links

• is related to: KAFKA-6298 Line numbers on log messages are incorrect
• links to: GitHub Pull Request #2465