Hi, Dhruba I got some questions while reading your design. 1. In section "Lease recovery", you said "Any Datanode that has a BlockGenerationStamp that is larger than what is stored in the BlocksMap is guaranteed to contain data from the last successful write to that block." To my understanding, BlockMap, which is stored in NameNode, always records the most recently mapping from file name to file blocks. When will the case that DataNode has a larger BlockGenerationStamp than that of in NameNode happen? 2. You said "The block size of each of these replicas could still be different because the write from a client might not have been committed to all replicas." To my understanding, before the client sends "CloseFile" request to NameNode, it must ensure that all of the replicas are written correctly.
On Nov 16, 2007 2:44 PM, dhruba Borthakur <[EMAIL PROTECTED]> wrote: > Actually, here is a more recent copy of the document: > > http://issues.apache.org/jira/secure/attachment/12369639/Appends.html > > thanks, > dhruba > > -----Original Message----- > From: dhruba Borthakur [mailto:[EMAIL PROTECTED] > Sent: Thursday, November 15, 2007 10:10 PM > To: [email protected] > Subject: RE: when will the feature HADOOP-1700 be implemented ? > > Hi Mafish, > > The design document is attached as a file Appends.doc (or Appends.html) > to the HADOOP-1700 bug description. Here is a direct link: > > http://issues.apache.org/jira/secure/attachment/12367999/Appends.htm > > If you are not able to access this link, please let me know and I will > email you a copy of the document. > > This design is currently under review. I am waiting for review comments. > > Thanks, > dhruba > > > -----Original Message----- > From: Mafish Liu [mailto:[EMAIL PROTECTED] > Sent: Thursday, November 15, 2007 5:54 PM > To: [email protected] > Subject: Re: when will the feature HADOOP-1700 be implemented ? > > Hello, Dhruba > Would you please give me a link where your design stands? > -- > [EMAIL PROTECTED] > Institute of Computing Technology, Chinese Academy of Sciences, Beijing, > China. > Tel: 86 10 62601317 > -- [EMAIL PROTECTED] Institute of Computing Technology, Chinese Academy of Sciences, Beijing.
