[ https://issues.apache.org/jira/browse/HDFS-989?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13145536#comment-13145536 ]
Robert Joseph Evans commented on HDFS-989: ------------------------------------------ Does HDFS have a similar issue with flush (Not flushing everything unless we are at a byte boundary)? It being a checksum file system as well. If so then I think we also need to update the documentation about when data is flushed and perhaps even provide an API so that a user can know how many bytes they may need to pad before the flush can happen as expected. From reading the documentation on trunk for Syncable it does not indicate at all that this might happen. {code} /** * @deprecated As of HADOOP 0.21.0, replaced by hflush * @see #hflush() */ @Deprecated public void sync() throws IOException; /** Flush out the data in client's user buffer. After the return of * this call, new readers will see the data. * @throws IOException if any error occurs */ public void hflush() throws IOException; /** Similar to posix fsync, flush out the data in client's user buffer * all the way to the disk device (but the disk may have it in its cache). * @throws IOException if error occurs */ public void hsync() throws IOException; {code} > Flush/sync do not work on Hadoop LocalFileSystem > ------------------------------------------------ > > Key: HDFS-989 > URL: https://issues.apache.org/jira/browse/HDFS-989 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 0.20.1 > Reporter: Nathan Marz > > They seem to be no-ops. This is really easy to reproduce, just open a file > using FileSystem/getLocal(new Configuration()), write data to the output > stream, and then try to flush/sync. I also tried creating the output stream > with a buffer size of 1, but that had no effect. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira