On each edit, a sequence id is incremented. When edits are applied to the commit log their sequence id is noted along with the entry. When we flush, the sequence id of the flushed edits are noted in the flush/store file. The regionserver will let go of commit logs (hlogs in hbase parlance) if all its edits have been flushed to the filesystem. It uses the sequence id figuring when it can do this. Sequence id is also used figuring which of a set of flush/store files is the newer (the file denoted by the larger sequence id will be newer) among other things.
Does this help? St.Ack On Tue, Aug 18, 2009 at 3:18 AM, chunping rao <[email protected]> wrote: > hi: > all > in the source code of hbase-0.20.0,i can't understand the use of the > attribute "MAX_SED_ID_KEY" ,what is the role of "MAX_SEQ_ID_KEY"? >
