Rotate and remove old Logstash output logs

Hello,

I've got a Logstash installation (centos 7.6, Logstash 7.2.0) which work great but produce logs and never delete them.
I've never changed any default configuration so the /etc/logstash/log4j2.properties files contains this :

status = error
name = LogstashPropertiesConfig

appender.console.type = Console
appender.console.name = plain_console
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %m%n

appender.json_console.type = Console
appender.json_console.name = json_console
appender.json_console.layout.type = JSONLayout
appender.json_console.layout.compact = true
appender.json_console.layout.eventEol = true

appender.rolling.type = RollingFile
appender.rolling.name = plain_rolling
appender.rolling.fileName = ${sys:ls.logs}/logstash-${sys:ls.log.format}.log
appender.rolling.filePattern = ${sys:ls.logs}/logstash-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.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
appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling.policies.size.size = 100MB
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.max = 30

appender.json_rolling.type = RollingFile
appender.json_rolling.name = json_rolling
appender.json_rolling.fileName = ${sys:ls.logs}/logstash-${sys:ls.log.format}.log
appender.json_rolling.filePattern = ${sys:ls.logs}/logstash-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.log.gz
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
appender.json_rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.json_rolling.policies.size.size = 100MB
appender.json_rolling.strategy.type = DefaultRolloverStrategy
appender.json_rolling.strategy.max = 30

rootLogger.level = ${sys:ls.log.level}
rootLogger.appenderRef.console.ref = ${sys:ls.log.format}_console
rootLogger.appenderRef.rolling.ref = ${sys:ls.log.format}_rolling

# Slowlog

appender.console_slowlog.type = Console
appender.console_slowlog.name = plain_console_slowlog
appender.console_slowlog.layout.type = PatternLayout
appender.console_slowlog.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %m%n

appender.json_console_slowlog.type = Console
appender.json_console_slowlog.name = json_console_slowlog
appender.json_console_slowlog.layout.type = JSONLayout
appender.json_console_slowlog.layout.compact = true
appender.json_console_slowlog.layout.eventEol = true

appender.rolling_slowlog.type = RollingFile
appender.rolling_slowlog.name = plain_rolling_slowlog
appender.rolling_slowlog.fileName = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}.log
appender.rolling_slowlog.filePattern = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.log.gz
appender.rolling_slowlog.policies.type = Policies
appender.rolling_slowlog.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling_slowlog.policies.time.interval = 1
appender.rolling_slowlog.policies.time.modulate = true
appender.rolling_slowlog.layout.type = PatternLayout
appender.rolling_slowlog.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %.10000m%n
appender.rolling_slowlog.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling_slowlog.policies.size.size = 100MB
appender.rolling_slowlog.strategy.type = DefaultRolloverStrategy
appender.rolling_slowlog.strategy.max = 30

appender.json_rolling_slowlog.type = RollingFile
appender.json_rolling_slowlog.name = json_rolling_slowlog
appender.json_rolling_slowlog.fileName = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}.log
appender.json_rolling_slowlog.filePattern = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.log.gz
appender.json_rolling_slowlog.policies.type = Policies
appender.json_rolling_slowlog.policies.time.type = TimeBasedTriggeringPolicy
appender.json_rolling_slowlog.policies.time.interval = 1
appender.json_rolling_slowlog.policies.time.modulate = true
appender.json_rolling_slowlog.layout.type = JSONLayout
appender.json_rolling_slowlog.layout.compact = true
appender.json_rolling_slowlog.layout.eventEol = true
appender.json_rolling_slowlog.policies.size.type = SizeBasedTriggeringPolicy
appender.json_rolling_slowlog.policies.size.size = 100MB
appender.json_rolling_slowlog.strategy.type = DefaultRolloverStrategy
appender.json_rolling_slowlog.strategy.max = 30

logger.slowlog.name = slowlog
logger.slowlog.level = trace
logger.slowlog.appenderRef.console_slowlog.ref = ${sys:ls.log.format}_console_slowlog
logger.slowlog.appenderRef.rolling_slowlog.ref = ${sys:ls.log.format}_rolling_slowlog
logger.slowlog.additivity = false

logger.licensereader.name = logstash.licensechecker.licensereader
logger.licensereader.level = error

As asked in this configuration, the files in /var/logs/logstash/ are rotated and compressed each day but they're never deleted. I still have logs from May 2019. (Mainly logstash-plain logs. logstash-slowlog-plain log is unique and empty).

I believed that the strategy.max = 30 config line would delete logs files older than 30 days, but I was wrong. ¯\_(ツ)_/¯

What's the correct configuration to remove old logs ?

I found this topic talking about a logrotate.d configuration, but I think it'll fight with this log4j2 configuration and I'm not sure of the result.

Thanks and regards,

In a configuration where filePattern contains %i I think strategy.max applies to that, so that you never get more than 30 files per day.

I tried this, but it had no effect. Perhaps you can get it to work by tuning it.

appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.delete.type = Delete
appender.rolling.strategy.delete.basePath = ${sys:ls.logs}
appender.rolling.strategy.delete.maxDepth = 1
appender.rolling.strategy.delete.ifLastModified.type = IfLastModified
appender.rolling.strategy.delete.ifLastModified.age = 30d
1 Like

Hello Badger,

Thanks for helping :slight_smile:
Is there documentation anywhere about the available options ? The delete configuration and all maxDepth, lastModified, and other options... where did you found that possibility ?

Thanks and regards,

The options are documented here. There is an example here.

Hello Badger,

Thanks for your help. It was successful !

Here's my final /etc/logstash/log4j2.properties file :

status = error
name = LogstashPropertiesConfig

appender.console.type = Console
appender.console.name = plain_console
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %m%n

appender.json_console.type = Console
appender.json_console.name = json_console
appender.json_console.layout.type = JSONLayout
appender.json_console.layout.compact = true
appender.json_console.layout.eventEol = true

appender.rolling.type = RollingFile
appender.rolling.name = plain_rolling
appender.rolling.fileName = ${sys:ls.logs}/logstash-${sys:ls.log.format}.log
appender.rolling.filePattern = ${sys:ls.logs}/logstash-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.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
appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling.policies.size.size = 100MB
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.max = 30
appender.rolling.strategy.delete.type = Delete
appender.rolling.strategy.delete.basePath = ${sys:ls.logs}
appender.rolling.strategy.delete.maxDepth = 1
appender.rolling.strategy.delete.ifLastModified.type = IfLastModified
# Delete files older than 30 days
appender.rolling.strategy.delete.ifLastModified.age = 30d

appender.json_rolling.type = RollingFile
appender.json_rolling.name = json_rolling
appender.json_rolling.fileName = ${sys:ls.logs}/logstash-${sys:ls.log.format}.log
appender.json_rolling.filePattern = ${sys:ls.logs}/logstash-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.log.gz
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
appender.json_rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.json_rolling.policies.size.size = 100MB
appender.json_rolling.strategy.type = DefaultRolloverStrategy
appender.json_rolling.strategy.max = 30
appender.json_rolling.strategy.delete.type = Delete
appender.json_rolling.strategy.delete.basePath = ${sys:ls.logs}
appender.json_rolling.strategy.delete.maxDepth = 1
appender.json_rolling.strategy.delete.ifLastModified.type = IfLastModified
# Delete files older than 30 days
appender.json_rolling.strategy.delete.ifLastModified.age = 30d

rootLogger.level = ${sys:ls.log.level}
rootLogger.appenderRef.console.ref = ${sys:ls.log.format}_console
rootLogger.appenderRef.rolling.ref = ${sys:ls.log.format}_rolling

# Slowlog

appender.console_slowlog.type = Console
appender.console_slowlog.name = plain_console_slowlog
appender.console_slowlog.layout.type = PatternLayout
appender.console_slowlog.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %m%n

appender.json_console_slowlog.type = Console
appender.json_console_slowlog.name = json_console_slowlog
appender.json_console_slowlog.layout.type = JSONLayout
appender.json_console_slowlog.layout.compact = true
appender.json_console_slowlog.layout.eventEol = true

appender.rolling_slowlog.type = RollingFile
appender.rolling_slowlog.name = plain_rolling_slowlog
appender.rolling_slowlog.fileName = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}.log
appender.rolling_slowlog.filePattern = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.log.gz
appender.rolling_slowlog.policies.type = Policies
appender.rolling_slowlog.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling_slowlog.policies.time.interval = 1
appender.rolling_slowlog.policies.time.modulate = true
appender.rolling_slowlog.layout.type = PatternLayout
appender.rolling_slowlog.layout.pattern = [%d{ISO8601}][%-5p][%-25c] %.10000m%n
appender.rolling_slowlog.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling_slowlog.policies.size.size = 100MB
appender.rolling_slowlog.strategy.type = DefaultRolloverStrategy
appender.rolling_slowlog.strategy.max = 30
appender.rolling_slowlog.strategy.delete.type = Delete
appender.rolling_slowlog.strategy.delete.basePath = ${sys:ls.logs}
appender.rolling_slowlog.strategy.delete.maxDepth = 1
appender.rolling_slowlog.strategy.delete.ifLastModified.type = IfLastModified
# Delete files older than 30 days
appender.rolling_slowlog.strategy.delete.ifLastModified.age = 30d

appender.json_rolling_slowlog.type = RollingFile
appender.json_rolling_slowlog.name = json_rolling_slowlog
appender.json_rolling_slowlog.fileName = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}.log
appender.json_rolling_slowlog.filePattern = ${sys:ls.logs}/logstash-slowlog-${sys:ls.log.format}-%d{yyyy-MM-dd}-%i.log.gz
appender.json_rolling_slowlog.policies.type = Policies
appender.json_rolling_slowlog.policies.time.type = TimeBasedTriggeringPolicy
appender.json_rolling_slowlog.policies.time.interval = 1
appender.json_rolling_slowlog.policies.time.modulate = true
appender.json_rolling_slowlog.layout.type = JSONLayout
appender.json_rolling_slowlog.layout.compact = true
appender.json_rolling_slowlog.layout.eventEol = true
appender.json_rolling_slowlog.policies.size.type = SizeBasedTriggeringPolicy
appender.json_rolling_slowlog.policies.size.size = 100MB
appender.json_rolling_slowlog.strategy.type = DefaultRolloverStrategy
appender.json_rolling_slowlog.strategy.max = 30
appender.json_rolling_slowlog.strategy.delete.type = Delete
appender.json_rolling_slowlog.strategy.delete.basePath = ${sys:ls.logs}
appender.json_rolling_slowlog.strategy.delete.maxDepth = 1
appender.json_rolling_slowlog.strategy.delete.ifLastModified.type = IfLastModified
# Delete files older than 30 days
appender.json_rolling_slowlog.strategy.delete.ifLastModified.age = 30d

logger.slowlog.name = slowlog
logger.slowlog.level = trace
logger.slowlog.appenderRef.console_slowlog.ref = ${sys:ls.log.format}_console_slowlog
logger.slowlog.appenderRef.rolling_slowlog.ref = ${sys:ls.log.format}_rolling_slowlog
logger.slowlog.additivity = false

logger.licensereader.name = logstash.licensechecker.licensereader
logger.licensereader.level = error

Maybe it could be useful to add theses configuration in the defaults file, don't you think ? I'm not sure anyone want to keep theses files for years :smiley:

Best regards,

2 Likes

Good for you :slight_smile: I just cannot get it to work :frowning:

Did you completely restart the service after the modification ?
If that works with me... that should work with you... :face_with_raised_eyebrow:

I know I restarted logstash because I do not run it as a service. If I need to run logstash I boot a cloud server and run it on the command line. It turns out there were two issues.

Firstly, although I had write access to the directory and log files via the group, which allowed me to delete files using rm, I did not own the log files. Once I used your configuration and chown'd the most recent file, all of the old files owned by the logstash user were deleted.

Secondly, I applied the changes to the appender.rolling. stanza in the log4j2.properties from the most recent version of logstash. That does not work. Specifically, to get size based rotation of /var/log/logstash-plain.log at 1 MB you have to set

appender.json_rolling.policies.size.size = 1MB

Even if you have

appender.rolling.policies.size.size = 100MB

it is the json_rolling size.size that is applied to the plain log. That is unexpected, at least to me.

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.