[LOG4J2-2353] log4j generate uncompressed .log.gz file with plain text when not all filePattern are using compression

• Type: Bug
• Status: Open
• Priority: Trivial
• Resolution: Unresolved
• Affects Version/s: 2.9.1
• Component/s: Core

Environment

CentOS & MacOS
JVM 1.8 (reproducible on latest build)

• Assignee: Unassigned
• Reporter: Julien
• Created: 15/Jun/18 09:28
• Updated: 15/Jun/18 16:17

Description

One appender filePattern is set with "log.gz", another appender is set with ".log". In this case what is observed is that the log.gz rollover with no compression, removing the appender with filePattern set with no compression work around this

Here is how log4j2.properties look like 

appender.rolling.type = RollingFile
appender.rolling.name = plain_rolling
appender.rolling.fileName = /path/plainlog.log
appender.rolling.filePattern = /path/plainlog-%d{yyyy-MM-dd-HH-mm-ss}.log.gz
appender.rolling.policies.type = Policies
appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling.policies.time.interval = 1
appender.rolling.policies.time.modulate = true
appender.rolling.layout.type = PatternLayout
appender.rolling.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %-.10000m%n

#This section/appender is not even used in the application as a setting is logging in plain
appender.json_rolling.type = RollingFile
appender.json_rolling.name = json_rolling
appender.json_rolling.fileName = /path/jsonlog.log
appender.json_rolling.filePattern = /path/jsonlog-%d{yyyy-MM-dd-HH-mm-ss}.log
appender.json_rolling.policies.type = Policies
appender.json_rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.json_rolling.policies.time.interval = 1
appender.json_rolling.policies.time.modulate = true
appender.json_rolling.layout.type = JSONLayout
appender.json_rolling.layout.compact = true
appender.json_rolling.layout.eventEol = true

 

 

With above configuration the following files will contain plain text

/path/plainlog-%d{yyyy-MM-dd-HH-mm-ss}.log.gz

Commenting out appender "json_rolling" or setting filePattern to .log.gz cause the plainlog-*.log.gz to be compressed as expected :

appender.json_rolling.filePattern = /path/jsonlog-%d{yyyy-MM-dd-HH-mm-ss}.log

 

I am expecting this is or was a Bug in log4j code or possibly documentation because I could not see this behaviour is documented clearly