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From Ted Yu <yuzhih...@gmail.com>
Subject Re: HBASE 3904
Date Tue, 28 Jun 2011 23:33:48 GMT
Comment for this issue is welcome.

Thanks

On Mon, Jun 20, 2011 at 5:38 PM, Ted Yu <yuzhihong@gmail.com> wrote:

> Can we wrap up 3904 with patch v5 and the following addition to javadoc of
> createTableAsync() ?
>
> If the client receives socket timeout exception, that implies master hasn't
> done populating .META. table with new region info.
> Meaning HConnection.isTableAvailable() may return true prematurely.
>
>
> On Mon, Jun 20, 2011 at 3:54 PM, Jean-Daniel Cryans <jdcryans@apache.org>wrote:
>
>> Well in that case you know how many regions you expect, we could catch
>> the socket exception and then check .META. until it's done or return
>> the call right away and keep checking .META.
>>
>> J-D
>>
>> On Mon, Jun 20, 2011 at 3:41 PM, Ted Yu <yuzhihong@gmail.com> wrote:
>> > Vidhyashankar did encounter socket timeout.
>> > I think even with HBASE-4010 implemented, 70k region table creation
>> would
>> > still produce socket timeout.
>> >
>> > On Mon, Jun 20, 2011 at 3:30 PM, Jean-Daniel Cryans <
>> jdcryans@apache.org>wrote:
>> >
>> >> Could be a socket timeout, was able to get one with just 200 regions,
>> >> then calling isTableAvailable would trigger the case that was
>> >> described.
>> >>
>> >> J-D
>> >>
>> >> On Mon, Jun 20, 2011 at 3:28 PM, Ted Yu <yuzhihong@gmail.com> wrote:
>> >> > J-D:
>> >> > What's your assessment of why isTableAvailable() was inaccurate for
a
>> >> table
>> >> > with 70k regions ?
>> >> >
>> >> > Thanks
>> >> >
>> >> > On Mon, Jun 20, 2011 at 3:01 PM, Jean-Daniel Cryans <
>> jdcryans@apache.org
>> >> >wrote:
>> >> >
>> >> >> That's not how it works, whether the createTable call is sync or
not
>> >> >> the regions are first created in .META. before the call can return.
>> >> >>
>> >> >> And looking at that code, it seems it's highly inefficient. We
>> should
>> >> >> not change the enable flag for every region, we should batch put
all
>> >> >> the .META. rows and we should not open a new HLog per new region.
>> >> >>
>> >> >> J-D
>> >> >>
>> >> >> On Mon, Jun 20, 2011 at 2:55 PM, Ted Yu <yuzhihong@gmail.com>
>> wrote:
>> >> >> > From Vidhyashankar @ 20/May/11 05:53:
>> >> >> > Hence there might be a case when all regions are indeed fully
>> assigned
>> >> in
>> >> >> > META but it is just that the master is yet to populate META
with
>> the
>> >> rest
>> >> >> of
>> >> >> > the regions.
>> >> >> >
>> >> >> > The above means scanning .META. alone wouldn't guarantee that
all
>> the
>> >> >> > regions of the table are assigned.
>> >> >> >
>> >> >>
>> >> >
>> >>
>> >
>>
>
>

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