pphust opened a new pull request #336: URL: https://github.com/apache/flume/pull/336
The issue: When file is renamed or rotated, just as it is in log4j or other similar log system, currently Flume taildirSource will treat it as a new file then all contents will be collected again. It will cause data duplicated, which has been described in [FLUME-3233](https://issues.apache.org/jira/browse/FLUME-3233)、 [FLUME-3219](https://issues.apache.org/jira/browse/FLUME-3219)、[FLUME-3094](https://issues.apache.org/jira/browse/FLUME-3094)、[FLUME-3216](https://issues.apache.org/jira/browse/FLUME-3216) and [FLUME-2777](https://issues.apache.org/jira/browse/FLUME-2777). The general solution is only monitor original *.log and NOT monitor the renamed *.log.xxx. But for below two reasons, we must monitor both *.log and renamed *.log.xxx: 1、 Sometimes log system uses async writting. Contents may be flushed to disk after file is renamed. If we do not monitor renamed *.log.xxx, the content will only be sent out when Flume close inactive file. Though Flume will send it out finally, but it will cause sending delay and curreny the interval is decided by _idleTimeout_, default 120 seconds. In many cases it is unacceptable. 2、Sometimes both service and Flume are shutdown. Service is restarted firstly then it writes something to *.log and rename it as *.log.xxx. If we do not monitor renamed *.log.xxx, the data will get lost certernly. The solution: The PR add a new _inodeOnly_ paramater and make taildirSource support file rename/rotation. By default, _inodeOnly_ is false and Flume just works same with now. When _inodeOnly_ in config is set as true, Flume only use inode to identify file then taildirSource will support file rename/rotation. And the above 2 problems will be solved perfectly. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
