[
https://issues.apache.org/jira/browse/HADOOP-14444?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16072439#comment-16072439
]
Lukas Waldmann commented on HADOOP-14444:
-----------------------------------------
Hongyuan, but files on ftp server are changed by a different application,
right? In any case, cache is is updated for any create/mkdir/write operation
performed of filesystem created by FileSystem fs = FileSystem.get(conf);
Outside changes are not monitored and if such situation is common cache should
be disabled.
Please, try new filesystem and let me know if you come across any problem. It
can be used independently of current file systems - see readme.md. So far we
used it internally to out full satisfaction.
> New implementation of ftp and sftp filesystems
> ----------------------------------------------
>
> Key: HADOOP-14444
> URL: https://issues.apache.org/jira/browse/HADOOP-14444
> Project: Hadoop Common
> Issue Type: New Feature
> Components: fs
> Affects Versions: 2.8.0
> Reporter: Lukas Waldmann
> Assignee: Lukas Waldmann
> Attachments: HADOOP-14444.2.patch, HADOOP-14444.3.patch,
> HADOOP-14444.patch
>
>
> Current implementation of FTP and SFTP filesystems have severe limitations
> and performance issues when dealing with high number of files. Mine patch
> solve those issues and integrate both filesystems such a way that most of the
> core functionality is common for both and therefore simplifying the
> maintainability.
> The core features:
> * Support for HTTP/SOCKS proxies
> * Support for passive FTP
> * Support of connection pooling - new connection is not created for every
> single command but reused from the pool.
> For huge number of files it shows order of magnitude performance improvement
> over not pooled connections.
> * Caching of directory trees. For ftp you always need to list whole directory
> whenever you ask information about particular file.
> Again for huge number of files it shows order of magnitude performance
> improvement over not cached connections.
> * Support of keep alive (NOOP) messages to avoid connection drops
> * Support for Unix style or regexp wildcard glob - useful for listing a
> particular files across whole directory tree
> * Support for reestablishing broken ftp data transfers - can happen
> surprisingly often
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org
