https://issues.apache.org/jira/browse/HADOOP-4539
This issue was closed long ago. But, Steve Loughran just said on tha hadoop mailing list that the new NN has to come up with the same IP/hostname as the failed one. J-D On Fri, Aug 7, 2009 at 2:37 AM, Ryan Rawson<[email protected]> wrote: > WAL is a major issue, but another one that is coming up fast is the > SPOF that is the namenode. > > Right now, namenode aside, I can rolling restart my entire cluster, > including rebooting the machines if I needed to. But not so with the > namenode, because if it does AWOL, all sorts of bad can happen. > > I hope that HDFS 0.21 addresses both these issues. Can we get > positive confirmation that this is being worked on? > > -ryan > > On Thu, Aug 6, 2009 at 10:25 AM, Andrew Purtell<[email protected]> wrote: >> I updated the roadmap up on the wiki: >> >> >> * Data integrity >> * Insure that proper append() support in HDFS actually closes the >> WAL last block write hole >> * HBase-FSCK (HBASE-7) -- Suggest making this a blocker for 0.21 >> >> I have had several recent conversations on my travels with people in >> Fortune 100 companies (based on this list: >> http://www.wageproject.org/content/fortune/index.php). >> >> You and I know we can set up well engineered HBase 0.20 clusters that >> will be operationally solid for a wide range of use cases, but given >> those aforementioned discussions there are certain sectors which would >> say HBASE-7 is #1 before HBase is "bank ready". Not until we can say: >> >> - Yes, when the client sees data has been committed, it actually has >> been written and replicated on spinning or solid state media in all >> cases. >> >> - Yes, we go to great lengths to recover data if ${deity} forbid you >> crush some underprovisioned cluster with load or some bizarre bug or >> system fault happens. >> >> HBASE-1295 is also required for business continuity reasons, but this >> is already a priority item for some HBase committers. >> >> The question is I think does the above align with project goals. >> Making HBase-FSCK a blocker will probably knock something someone >> wants for the 0.21 timeframe off the list. >> >> - Andy >> >> >> >
