Styjun

Since I don't find an answer to this, apologies if it's seen as a duplicate to some other questions.

I use SiftingAppender to create different log files for each service (3 services) and TimeBasedRollingPolicy so the rollover of log files happens every day.

The LogDiscriminator.java generates the log_discriminator for SiftingAppender policy for logback. Two cases here:

• Case 1 (LogDiscriminator.java) - logback is able to delete log files after 10 days (maxHistory set to 10)


• Case 2 (LogDiscriminator.java) - added UUID (just to distingush between instances of the same service - e.g. 2 instances of ser_1), logback is not able to remove log files after 10 days.

Please, is it possible to remove logs older than MaxHistory only based on date? I mean no matter the name (case 2), logback will be able to remove log files. Is there another way to achieve this?

Logback

<?xml version="1.0"?>
<configuration>
 <!-- ... -->
 <appender name="MAIN" class="ch.qos.logback.classic.sift.SiftingAppender">
 <discriminator>
 <key>log_discriminator</key>
 <defaultValue>LOG_FILE_KEY_UNKNOWN</defaultValue>
 </discriminator>
 <sift>
 <appender name="FILE-$log_discriminator" class="ch.qos.logback.core.rolling.RollingFileAppender">
 <file>$log.folder/$log_discriminator.log</file>
 <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
 <!-- daily roll-over -->
 <FileNamePattern>$log.folder/$log_discriminator.%dyyyy-MM-dd.log</FileNamePattern>
 <maxHistory>10</maxHistory>
 <cleanHistoryOnStart>true</cleanHistoryOnStart>
 </rollingPolicy>
 <encoder>
 <pattern>$log.pattern</pattern>
 </encoder>
 <prudent>true</prudent>
 </appender>
 </sift>
 </appender>
 <!-- ... -->
</configuration>

LogDiscriminator.java

public class LogDiscriminator 
 ...
 public static void setLogFileType(String appType) 
 // Case 1 - logback was able to delete after 10 days of log 
 // MDC.put("log_discriminator", appType); // e.g. ser_1, ser_2 or ser_3 (3 services)

 // Case 2 - added UUID (just to distingush between instances of the same app - e.g. 2 instances of ser_1), logback is not able to delete
 MDC.put("log_discriminator", String.format("%s_%s", appType, UUID.randomUUID().toString()));
 
 ...