hbase-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Xi Yang <alex.xi.y...@gmail.com>
Subject Re: What if I want to write another table in MasterObserver.preModifyColumnFamily ?
Date Wed, 08 Mar 2017 02:56:54 GMT
Got it. I appreciate your help!

2017-03-07 17:05 GMT-08:00 Ted Yu <yuzhihong@gmail.com>:

> It seems the following hook is better for your use case:
>
>   default void postModifyColumn(final
> ObserverContext<MasterCoprocessorEnvironment> ctx,
>       TableName tableName, HColumnDescriptor columnFamily) throws
> IOException {}
>
> since there is no guarantee that column family is modified at
> time preModifyColumnFamily() is called.
>
> Cheers
>
> On Tue, Mar 7, 2017 at 4:43 PM, Xi Yang <alex.xi.yang@gmail.com> wrote:
>
> > Requirement:
> >
> > I want to record every change of modify columnFamily by using
> > preModifyColumnFamily().
> > Now I have a table "my_ddl_log" which used to record the change of
> > columnFamily. For example:
> >
> > If jack change the TTL of columnFamily "primary" in table "employee".
> Then
> > we should add a put to "my_ddl_log" like this record:
> > log:name= 'jack'
> > log:updateTime= '2017-03-07 12:12 GMT-08:00'
> > log:change= ''Change TTL of Table: employee ColumnFamily: primary'
> >
> > I try to use preModifyColumnFamily to do this stuff.
> >
> > Thanks,
> > Alex
> >
> >
> > 2017-03-07 12:12 GMT-08:00 Ted Yu <yuzhihong@gmail.com>:
> >
> > > Describing your use case would allow people to give better answer.
> > >
> > > What kind of data do you write to other table in
> preModifyColumnFamily()
> > ?
> > >
> > > Cross server call within observer is not good idea.
> > >
> > > Take a look at ConnectionUtils.createShortCircuitConnection().
> > >
> > > Cheers
> > >
> > > On Tue, Mar 7, 2017 at 11:42 AM, Xi Yang <alex.xi.yang@gmail.com>
> wrote:
> > >
> > > >     All the articles I've ever seen are talking about add increment
> or
> > > > change put/get status or pinrt out logs. what if I want to write some
> > > data
> > > > to another table in Observer? For
> > > > example, MasterObserver.preModifyColumnFamily()? Seems Observer is
> > > runing
> > > > at server side, so use connection is unneccessary and might raise
> some
> > > > problem.
> > > >    I know this might be a stupid question, so if you can just give
> some
> > > > links let me to learn without explain in email, I will be grateful to
> > you
> > > > for your help
> > > >
> > > > Thanks,
> > > > Alex
> > > >
> > >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message