Hiya, We’ve recently upgraded to 0.9. In 0.8, when we restarted a broker, data log file mtimes were not changed. In 0.9, any data log file that was on disk before the broker has it’s mtime modified to the time of the broker restart.
This causes problems with log retention, as all the files then look like they contain recent data to kafka. We use the default log retention of 7 weeks, but if all the files are touched at the same time, this can cause us to retain up to 2 weeks of log data, which can fill up our disks. We saw this during our initial upgrade, but I had just thought it had something to do with the change of inter.broker.protocol.version, and assumed it wouldn’t happen again. We just did our first broker restart after the upgrade, and we are seeing this again. We worked around this during our upgrade by temporarily setting a high volume topic’s retention very low, causing brokers to purge more recent data. This allowed us to avoid filling up our disks, but we shouldn’t have to do this every time we bounce brokers. Has anyone else noticed this? -Ao
