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From Lars George <lars.geo...@gmail.com>
Subject Re: hbase:meta blocks in L1?
Date Fri, 15 Jul 2016 08:06:51 GMT
I just checked on 1.2.1, using the "as JSON by File", then searching
for the cached file (the hash). And yes, the hbase:meta blocks are in
L2 once you enable it. So the missing setCacheDataInL1(true) for the
metaTableDescriptor() method is causing this.

On Fri, Jul 15, 2016 at 2:08 AM, Ted Yu <yuzhihong@gmail.com> wrote:
> I looked at related code in branch-1.
> HColumnDescriptor#isCacheDataInL1() uses default value of
> HColumnDescriptor.DEFAULT_CACHE_DATA_IN_L1 which is false
>
> I think setCacheDataInL1(true) call is needed for meta HTableDescriptor
>
> On Thu, Jul 14, 2016 at 12:57 PM, Nick Dimiduk <ndimiduk@gmail.com> wrote:
>
>> IIRC, the configuration handling and IoC of multi-level block cache changed
>> significantly around 1.2. This was to facilitate an overhaul and overall
>> improvement of how cache layers are built, defined, and configured.
>> Structures may be quite different between master and various incarnations
>> of 1.x branches. Please examine each independently, don't assume what holds
>> on one branch applies to another.
>>
>> On Thu, Jul 14, 2016 at 12:35 PM, Ted Yu <yuzhihong@gmail.com> wrote:
>>
>> > Interesting.
>> >
>> > Do you want to log a JIRA ?
>> >
>> > I checked HTableDescriptor.java in branch-1.1 to branch-1 where
>> > setCacheDataInL1(true) is missing.
>> >
>> > The fix would be a one line change.
>> >
>> > On Thu, Jul 14, 2016 at 11:43 AM, Lars George <lars.george@gmail.com>
>> > wrote:
>> >
>> > > Ah wait, this was fixed in
>> > > https://issues.apache.org/jira/browse/HBASE-15467, but is not right
>> > > (if I read this proper) in the 1.x line. It could mean that hbase:meta
>> > > is cached in L2 only.
>> > >
>> > > On Thu, Jul 14, 2016 at 7:37 PM, Ted Yu <yuzhihong@gmail.com> wrote:
>> > > > Looking at FSTableDescriptors#createMetaTableDescriptor() , both
>> column
>> > > > families have the following:
>> > > >
>> > > >                 .setCacheDataInL1(true),
>> > > >
>> > > > Is there something else you were looking for ?
>> > > >
>> > > > Cheers
>> > > >
>> > > > On Thu, Jul 14, 2016 at 6:59 AM, Lars George <lars.george@gmail.com>
>> > > wrote:
>> > > >
>> > > >> Hey,
>> > > >>
>> > > >> HBASE-11364 did add `.setCacheDataInL1(true)`, but the later change
>> to
>> > > >> use `HTableDescriptor.metaTableDescriptor()` changes the layout
of
>> the
>> > > >> `hbase:meta` to omit the L1 cache setting. Is this on purpose
or an
>> > > >> oversight?
>> > > >>
>> > > >> In other words, are the meta blocks currently never cached in
L1?
>> > > >>
>> > > >> Lars
>> > > >>
>> > >
>> >
>>

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