Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase, mail # user - drop table


Copy link to this message
-
Re: drop table
Mohammad Tariq 2012-07-23, 20:40
Also, we don't have to worry about compaction under normal conditions.
When something is written to HBase, it is first written to an
in-memory store (memstore), once this memstore reaches a certain size,
it is flushed to disk into a store file (everything is also written
immediately to a log file for durability). The store files created on
disk are immutable. Sometimes the store files are merged together,
this is done by a process called compaction.

Regards,
    Mohammad Tariq
On Tue, Jul 24, 2012 at 2:00 AM, Mohammad Tariq <[EMAIL PROTECTED]> wrote:
> The HBase processes exposes a web-based user interface (in short UI),
> which you can use to gain insight into the cluster's state, as well as
> the tables it hosts. Just point your web browser to
> "http://hmaster:60010". Although majority of the functionality is
> read-only, but there are a few selected operation you can trigger
> through the UI(like splitting and compaction).
>
> Regards,
>     Mohammad Tariq
>
>
> On Tue, Jul 24, 2012 at 1:56 AM, Rob Roland <[EMAIL PROTECTED]> wrote:
>> You don't have to run the major compaction - the shell is doing that for
>> you.  You must disable the table first, like:
>>
>> disable 'session_timeline'
>> drop 'session_timeline'
>>
>> See the admin.rb file:
>>
>>     def drop(table_name)
>>       tableExists(table_name)
>>       raise ArgumentError, "Table #{table_name} is enabled. Disable it
>> first.'" if enabled?(table_name)
>>
>>       @admin.deleteTable(table_name)
>>       flush(org.apache.hadoop.hbase.HConstants::META_TABLE_NAME)
>>       major_compact(org.apache.hadoop.hbase.HConstants::META_TABLE_NAME)
>>     end
>>
>> On Mon, Jul 23, 2012 at 1:22 PM, Mohit Anchlia <[EMAIL PROTECTED]>wrote:
>>
>>> Thanks! but I am still trying to understand these 2 questions:
>>>
>>> 1. How to see if this table has more than one region?
>>> 2. And why do I need to run major compact if I have more than one region?
>>>
>>> On Mon, Jul 23, 2012 at 1:14 PM, Mohammad Tariq <[EMAIL PROTECTED]>
>>> wrote:
>>>
>>> > Hi Mohit,
>>> >
>>> >       A table must be disabled first in order to get deleted.
>>> > Regards,
>>> >     Mohammad Tariq
>>> >
>>> >
>>> > On Tue, Jul 24, 2012 at 1:38 AM, Mohit Anchlia <[EMAIL PROTECTED]>
>>> > wrote:
>>> > > I am trying to drop one of the tables but on the shell I get run
>>> > > major_compact. I have couple of questions:
>>> > >
>>> > > 1. How to see if this table has more than one region?
>>> > > 2. And why do I need to run major compact
>>> > >
>>> > >
>>> > > hbase(main):010:0* drop 'SESSION_TIMELINE'
>>> > >
>>> > > ERROR: Table SESSION_TIMELINE is enabled. Disable it first.'
>>> > >
>>> > > Here is some help for this command:
>>> > >
>>> > > Drop the named table. Table must first be disabled. If table has
>>> > >
>>> > > more than one region, run a major compaction on .META.:
>>> > >
>>> > > hbase> major_compact ".META."
>>> >
>>>