Thanks for all your suggestion and talk. One idea occurs to me why not check or restore wal when compaction executes. If it does, hbase can drop some unused hlog, I think that will be effective to the issue. please correct me if I am wrong.
---Bing 2012/11/22 lars hofhansl <[email protected]> > I have it on my list of things to do to allow deferred WAL flush as a per > operation option (right now it's a CF option). > You really do not want to do anything with the WAL off. If you use > deferred flush there is still a chance that this might happen (the RS could > die in the few seconds after a Delete before it is flushed to the WAL), but > it should be a rare occurrance. > > > -- Lars > > > > ________________________________ > From: Bing Jiang <[email protected]> > To: [email protected] > Sent: Wednesday, November 21, 2012 7:20 AM > Subject: Re: delete rows without writing HLog may be appear in the future? > > we need to confirm that put must be safe,but deletes must be quick and > low-latency. > On Nov 21, 2012 11:10 PM, "Michael Segel" <[email protected]> > wrote: > > > Some time later? > > > > Time of course is relative, so I have to ask what occurred between the > > write and the delete? > > How much time? Did you have any compactions in between the write and the > > delete? > > > > Why are you not consistent in your use of the WAL ? > > > > > > On Nov 21, 2012, at 6:37 AM, Bing Jiang <[email protected]> > wrote: > > > > > hi，all. > > > I want to describe a phenomenon that happens to our hbase cluster. > > > I use puts(List<Put>) to insert many records with writing hlog enable, > > > and some time later I delete all of these records with writing hlog > > disable. > > > When one week later, i scan the table, I found some records I have > delete > > > reappear again. > > > It is an interesting case. In my opinion, if we delete data without > > enable > > > writing hlog, when regionserver fails, the log will replay in another > > > regionserver. > > > Can anyone tell me if I persist on deleting records without enable > > writing > > > hlog, is there a way to prevent these records from reappearing again > some > > > time later? > > > > > > Cheers! > > > -- > > > Bing Jiang > > > weibo: http://weibo.com/jiangbinglover > > > BLOG: http://blog.sina.com.cn/jiangbinglover > > > BLOG: http://www.binospace.com > > > National Research Center for Intelligent Computing Systems > > > Institute of Computing technology > > > Graduate University of Chinese Academy of Science > > > > > -- Bing Jiang Tel：(86)134-2619-1361 weibo: http://weibo.com/jiangbinglover BLOG: http://blog.sina.com.cn/jiangbinglover National Research Center for Intelligent Computing Systems Institute of Computing technology Graduate University of Chinese Academy of Science
