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Jean-Daniel Cryans commented on HDFS-265: ----------------------------------------- We have been trying this patch for some time now on sequence files in HBase for the write ahead logs by syncing the writers output stream. I experimented by doing fast increments on a single cell at a rate of 800-900 operations a second and then killing -9 both the DN and RS after some time. I then waited for the master to recover the WAL and all edits (I log every of them locally) were present. I tried it dozens of times, killing machines after machines, and it works every time. +1 > Revisit append > -------------- > > Key: HDFS-265 > URL: https://issues.apache.org/jira/browse/HDFS-265 > Project: Hadoop HDFS > Issue Type: Improvement > Affects Versions: Append Branch > Reporter: Hairong Kuang > Assignee: Hairong Kuang > Fix For: Append Branch > > Attachments: a.sh, appendDesign.pdf, appendDesign.pdf, > appendDesign1.pdf, appendDesign2.pdf, AppendSpec.pdf, AppendTestPlan.html, > AppendTestPlan.html, AppendTestPlan.html, AppendTestPlan.html, > AppendTestPlan.html, AppendTestPlan.html, AppendTestPlan.html, > TestPlanAppend.html > > > HADOOP-1700 and related issues have put a lot of efforts to provide the first > implementation of append. However, append is such a complex feature. It turns > out that there are issues that were initially seemed trivial but needs a > careful design. This jira revisits append, aiming for a design and > implementation supporting a semantics that are acceptable to its users. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.