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HBase, mail # user - Overwrite a row


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Kristoffer Sjögren 2013-04-19, 17:53
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Ted Yu 2013-04-19, 18:32
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Kristoffer Sjögren 2013-04-19, 19:44
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Ted Yu 2013-04-19, 21:21
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Mohamed Ibrahim 2013-04-19, 18:11
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Mohamed Ibrahim 2013-04-19, 20:35
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Mohamed Ibrahim 2013-04-19, 20:41
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Ted Yu 2013-04-20, 02:47
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Kristoffer Sjögren 2013-04-20, 07:17
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Ted Yu 2013-04-20, 12:42
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Kristoffer Sjögren 2013-04-20, 17:11
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Ted Yu 2013-04-21, 00:25
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Anoop John 2013-04-21, 07:39
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Re: Overwrite a row
Kristoffer Sjögren 2013-04-22, 18:59
Interesting. RowMutation is a great API improvement, I shall have a look at
multirowmutation as well.

Thanks!
On Sun, Apr 21, 2013 at 9:39 AM, Anoop John <[EMAIL PROTECTED]> wrote:

> You can use MultiRowMutationEndpoint for atomic op on multiple rows (within
> same region)..
>
>
> On Sun, Apr 21, 2013 at 5:55 AM, Ted Yu <[EMAIL PROTECTED]> wrote:
>
> > Here is code from 0.94 code base:
> >
> >   public void mutateRow(final RowMutations rm) throws IOException {
> >     new ServerCallable<Void>(connection, tableName, rm.getRow(),
> >         operationTimeout) {
> >       public Void call() throws IOException {
> >         server.mutateRow(location.getRegionInfo().getRegionName(), rm);
> >         return null;
> >
> > where RowMutations has the following check:
> >
> >   private void internalAdd(Mutation m) throws IOException {
> >     int res = Bytes.compareTo(this.row, m.getRow());
> >     if(res != 0) {
> >       throw new IOException("The row in the recently added Put/Delete " +
> >           Bytes.toStringBinary(m.getRow()) + " doesn't match the original
> > one " +
> >           Bytes.toStringBinary(this.row));
> >
> > This means you need to issue multiple mutateRow() calls for different
> rows.
> >
> > I think you should consider the potential impact on performance due to
> this
> > limitation.
> >
> > For advanced usage, take a look at MultiRowMutationEndpoint:
> >
> >  * This class demonstrates how to implement atomic multi row transactions
> > using
> >  * {@link HRegion#mutateRowsWithLocks(java.util.Collection,
> > java.util.Collection)}
> >  * and Coprocessor endpoints.
> >
> > Cheers
> >
> > On Sat, Apr 20, 2013 at 10:11 AM, Kristoffer Sjögren <[EMAIL PROTECTED]
> > >wrote:
> >
> > > Just to absolutely be clear, is this also true for a batch that span
> > > multiple rows?
> > >
> > >
> > > On Sat, Apr 20, 2013 at 2:42 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
> > >
> > > > Operations within each batch are atomic.
> > > > They would either all succeed or all fail.
> > > >
> > > > Time stamps would all refer to the latest cell (KeyVal).
> > > >
> > > > Cheers
> > > >
> > > > On Apr 20, 2013, at 12:17 AM, Kristoffer Sjögren <[EMAIL PROTECTED]>
> > > wrote:
> > > >
> > > > > The schema is known beforehand so this is exactly what I need.
> Great!
> > > > >
> > > > > One more question. What guarantees does the batch operation have?
> Are
> > > the
> > > > > operations contained within each batch atomic? I.e. all mutations
> > will
> > > be
> > > > > given the same timestamp? If something fails, all operation fail or
> > can
> > > > it
> > > > > fail partially?
> > > > >
> > > > > Thanks for your help, much appreciated.
> > > > >
> > > > > Cheers,
> > > > > -Kristoffer
> > > > >
> > > > >
> > > > > On Sat, Apr 20, 2013 at 4:47 AM, Ted Yu <[EMAIL PROTECTED]>
> wrote:
> > > > >
> > > > >> I don't know details about Kristoffer's schema.
> > > > >> If all the column qualifiers are known a priori, mutateRow()
> should
> > > > serve
> > > > >> his needs.
> > > > >>
> > > > >> HBase allows arbitrary number of columns in a column family. If
> the
> > > > schema
> > > > >> is dynamic, mutateRow() wouldn't suffice.
> > > > >> If the column qualifiers are known but the row is very wide (and a
> > few
> > > > >> columns are updated per call), performance would degrade.
> > > > >>
> > > > >> Just some factors to consider.
> > > > >>
> > > > >> Cheers
> > > > >>
> > > > >> On Fri, Apr 19, 2013 at 1:41 PM, Mohamed Ibrahim <
> > > [EMAIL PROTECTED]
> > > > >>> wrote:
> > > > >>
> > > > >>> Actually I do see it in the 0.94 JavaDocs (
> > > > >>
> > > >
> > >
> >
> http://hbase.apache.org/0.94/apidocs/org/apache/hadoop/hbase/client/HTable.html#mutateRow(org.apache.hadoop.hbase.client.RowMutations)
> > > > >>> ),
> > > > >>> so may be it was added in 0.94.6 even though the jira says fixed
> in
> > > > 0.95
> > > > >> .
> > > > >>> I haven't used it though, but it seems that's what you're looking
> > > for.
> > > > >>>
> > > > >>> Sorry for confusion.