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From "M. C. Srivas" <mcsri...@gmail.com>
Subject Re: java.lang.NoSuchMethodException: hbase-0.90
Date Fri, 07 Jan 2011 19:32:37 GMT
On Fri, Jan 7, 2011 at 10:30 AM, Stack <stack@duboce.net> wrote:

> On Fri, Jan 7, 2011 at 7:53 AM, Ted Dunning <tdunning@maprtech.com> wrote:
> > This is on 0.90, right?  Were you using HDFS to store your region tables?
> >
> > I just ran into the same thing and looked into the
> >
> org.apache.hadoop.hbase.regionserver.wal.SequenceFileLogReader$WALReader$WALReaderFSDataInputStream.getPos
> > method.
> >
> > That method does some truly hideous reflection things without checking
> that
> > the objects involved actually are the correct type.  It also pierces the
> > visibility constraints on fields internal to objects by manipulating
> their
> > visibility.
> >
> > Is that code really necessary?  Is there a good way to make it less
> > sensitive to violation of its assumptions?
> >
>
> Yeah, its ugly, but acrobatics were required to get around dumb
> dfsclient limitation (See hbase-3038).
>
> As to your question Ted, it does seem like we could do the reflection
> once-only in the constructor rather than every time we do a getPos.
> Let me ask Nicolas.  Maybe he had reason for having to do it each
> time.  As to its assumptions, what you think?  It assumes class has a
> data member named 'in' and that file length is a long which seems safe
> enough.  Otherwise, its just changing accessibility.
>
>
> > My own situation is a bit unusual since I was testing hbase on a non-HDFS
> > file system, but Abinash's experience makes it seem that there is
> something
> > worse going on.
> >
>
> Ted, you need something changed?  If so, lets do it now before I roll
> next 0.90.0RC.
>

How about checking to see if "in" is instanceOf  DFSInputStream before doing
the rest of the stuff?



>
> St.Ack
>

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