logback 踩坑

1. totalSizeCap 配置大于 2GB 时，不生效的问题

logbakc.xml 配置

<appender name="info_rolling"
          class="ch.qos.logback.core.rolling.RollingFileAppender">
    <File>${logger.path}/info.log</File>
    <encoder charset="${logger.charset}">
        <pattern>${logger.pattern}</pattern>
    </encoder>
    <filter class="ch.qos.logback.classic.filter.LevelFilter">
        <level>INFO</level>
        <onMatch>ACCEPT</onMatch>
        <onMismatch>DENY</onMismatch>
    </filter>
    <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
        <fileNamePattern>
            ${logger.path}/info.%d{yy-MM-dd}.%i.log
        </fileNamePattern>
        <maxHistory>${logger.maxHistory}</maxHistory>
        <maxFileSize>512MB</maxFileSize>
        <totalSizeCap>5GB</totalSizeCap>
    </rollingPolicy>
</appender>

logback-core-1.1.11.jar 及之前版本的 TimeBasedArchiveRemover

void capTotalSize(Date now) {
    int totalSize = 0;
    int totalRemoved = 0;
    for (int offset = 0; offset < maxHistory; offset++) {
        Date date = rc.getEndOfNextNthPeriod(now, -offset);
        File[] matchingFileArray = getFilesInPeriod(date);
        descendingSortByLastModified(matchingFileArray);
        for (File f : matchingFileArray) {
            long size = f.length();
            if (totalSize + size > totalSizeCap) {
                addInfo("Deleting [" + f + "]" + " of size " + new FileSize(size));
                totalRemoved += size;
                f.delete();
            }
            totalSize += size;
        }
    }
    addInfo("Removed  " + new FileSize(totalRemoved) + " of files");
}

这里的totalSize使用的是int类型，Interger.MAX_VALUE最大只能表示2GB的数据，修改成使用long类型可以解决这个问题。

logback-core 1.2.0 之后的版本已经修复这个问题

void capTotalSize(Date now) {
    long totalSize = 0;
    long totalRemoved = 0;
    for (int offset = 0; offset < maxHistory; offset++) {
        Date date = rc.getEndOfNextNthPeriod(now, -offset);
        File[] matchingFileArray = getFilesInPeriod(date);
        descendingSortByLastModified(matchingFileArray);
        for (File f : matchingFileArray) {
            long size = f.length();
            if (totalSize + size > totalSizeCap) {
                addInfo("Deleting [" + f + "]" + " of size " + new FileSize(size));
                totalRemoved += size;
                f.delete();
            }
            totalSize += size;
        }
    }
    addInfo("Removed  " + new FileSize(totalRemoved) + " of files");
}