Thanks Arun. Change the mTime is a good idea. However, given a file (the path is
A/B/C/D/file) distributed to all the nodes, if I just change the mTime of file to a earlier time stamp, it will not be replaced next time. Should I also change the mTime for all the directories along the path (A, B, C and D). Whose timestamp is used by DistributedCache? Thanks. -Gang ----- 原始邮件 ---- 发件人： Arun C Murthy <a...@yahoo-inc.com> 收件人： mapreduce-u...@hadoop.apache.org 发送日期： 2010/8/22 (周日) 9:38:02 下午 主 题： Re: where distributed cache start working Moving to mapreduce-user@, bcc common-...@. Please use the project specific lists. DistributedCache.purgeCache isn't a public api. You shouldn't be calling it from the task. A simple way of doing what you want is to change the mtime of the cache files on HDFS. Arun On Aug 22, 2010, at 9:48 AM, Gang Luo wrote: > Thanks Jeff. > > However, are you sure TaskRunner.run() is also used in the new API? I use >btrace > to trace the function call but didn't find this function had been called > anywhere. > > > One more question about distributed cache. After I call > DistributedCache.purgeCache, I think the local cached files should be deleted >or > invalidated. However ,When I run the same job with the purge operation at the > end multiple times, I find the local files have never been deleted and the > modification time is when the first job run. How can I ask my job to > re-distributed the cache again anyway? > > Thanks, > -Gang > > > > > ----- 原始邮件 ---- > 发件人： Jeff Zhang <zjf...@gmail.com> > 收件人： common-dev@hadoop.apache.org > 发送日期： 2010/8/20 (周五) 11:22:49 上午 > 主 题： Re: where distributed cache start working > > Hi Gang, > > In the TaskRunner's run() method, hadoop will download the cache files > which you set on the client side to local, then the forked child jvm > can use these cache files locally. > > > > On Fri, Aug 20, 2010 at 8:08 AM, Gang Luo <lgpub...@yahoo.com.cn> wrote: >> Hi all, >> I go through the code, but couldn't find the place where distributed cache >> start >> working. I want to know between DistriubtedCache.addCacheFile at the master >> node >> and DistributedCache.getLocalCacheFiles at the client side, when and where are >> the files get distributed. >> >> >> Thanks, >> -Gang >> >> >> >> >> > > > > --Best Regards > > Jeff Zhang > > > >
