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From stack <st...@duboce.net>
Subject Re: MAX_SEQ_ID_KEY in StoreFile
Date Tue, 18 Aug 2009 17:02:48 GMT
Thanks.  I missed it grepping.

Each hfile has written into its metadata its maximums sequence (edit) number
-- the sequence id of its last entry.  MAX_SEQ_ID_KEY is the key used
writing this attribute into the hfile metadata map.

St.Ack



On Tue, Aug 18, 2009 at 9:55 AM, chunping rao <anty.rao@gmail.com> wrote:

>  hi:
>   stack
>    MAX_SEQ_ID_KEY is in the StoreFile.java of package
> org.apache.hadoop.hbase.regionserver.....Sorry ,i do not known exactly the
> version of  my hbase.
>
>
> 2009/8/19 stack <stack@duboce.net>
>
> > Oops.  Sorry.  Answered wrong question.
> >
> > I grepped source in 0.19 and 0.20 branches and don't see MAX_SEQ_ID_KEY.
> > Where are you seeing that?
> >
> > Thanks,
> > St.Ack
> >
> >
> >
> > On Tue, Aug 18, 2009 at 9:43 AM, stack <stack@duboce.net> wrote:
> >
> > > 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 <anty.rao@gmail.com>
> > 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"?
> > >>
> > >
> > >
> >
>

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