FSHLog (in trunk) stores the earliest seqnums for each region in current memstore, and earliest flushing seqnum (see FSHLog::start/complete/abortCacheFlush). When logs are deleted the logs with seqnums that are above the earliest flushing/flushed seqnum for any region are not deleted (see FSHLog::cleanOldLogs).
On Wed, May 22, 2013 at 5:39 AM, Bing Jiang <[email protected]>wrote: > Hi,all > I want to know how RS eliminates the unnecessary hlogs. > lastSeqNum stores <RegionName, latest KV Seq id> > and > outputfiles stores <last Seq id before new hlog file, file path> > > So, how does rs guarantee that the kv in the hlog to be cleared have been > already flushed from memstore into hfile. > I have try to read source code to make sense, however, I am not sure > whether it is a source of the risk of data loss. > > Thanks. > -- > 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 >
