hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Josh Elser <els...@apache.org>
Subject Re: Query on rowkey distribution || Does RS and number of Region related with each other
Date Fri, 31 Aug 2018 13:19:15 GMT
I'd like to remind you again that we're all volunteers and we're helping 
you because we choose to do so. Antagonizing those who are helping you 
is a great way to stop receiving any free help.

If you do not create more than one Region, HBase will not distribute 
your data on more than one RegionServer. Full stop.

On 8/30/18 2:16 PM, Manjeet Singh wrote:
> Hi Elser
> 
> I have clearly total about rowkey does I am talking about data? see below
> what I have told about rowkey
> 
> SALT_ID_DayStartTimestamp_DayEndTimeStamp_IDTimeStamp
> 
> Problem is this you are not understanding the question and just telling
> what you know, even on slack you are saying same thing.
> Question is simple if I put salt (which can be any arbit char or genrated
> hash any thing) at the begning of the rowkey why my data not getting
> distributed
> Please note this is not pre splitted table.
> 
> Thanks
> Manjeet Singh
> 
> On Thu, Aug 30, 2018 at 9:11 PM Josh Elser <elserj@apache.org> wrote:
> 
>> As I've been trying to explain in Slack:
>>
>> 1. Are you including the salt in the data that you are writing, such
>> that you are spreading the data across all Regions per their boundaries?
>> Or, as I think you are, just creating split points with this arbitrary
>> "salt" and not including it when you write data?
>>
>> If, as I am assuming, you are not, all of your data will go into the
>> first or last region. If you are still not getting my point, I'd suggest
>> that you share the exact splitpoints and one rowkey that you are writing
>> to HBase. That will make it quite clear if my guess is correct or not.
>>
>> 2. The number of Regions controls the number of RegionServers that will
>> be involved with reads/writes against that table. This is a calculation
>> that you need to figure out based on your cluster configuration and the
>> magnitude of your workload.
>>
>> On 8/30/18 1:11 AM, Manjeet Singh wrote:
>>> Hi All,
>>>
>>>
>>>
>>> I have two Question
>>>
>>> *Question 1 : *
>>>
>>> I want to understand how rowkey distribution happen if I create my table
>>> with out applying any policy but opting prefix salting.
>>>
>>> Example I have rowkey like
>>>
>>> SALT_ID_DayStartTimestamp_DayEndTimeStamp_IDTimeStamp
>>>
>>> So it will look like as below
>>>
>>> *_99_1516838400_1516924800_1516865160
>>>
>>> Question is : now I can not see that my data is getting distributed only
>>> because of salt.
>>>
>>> So does I have only choice of pre splitting? Or do I have any other
>> option?
>>>
>>> I have seen two more approaches
>>>
>>> i.e.
>>>
>>> hbase org.apache.hadoop.hbase.util.RegionSplitter test_table
>> HexStringSplit
>>> -c 10 -f f1
>>>
>>> I guess its scope is limited as number of region created at the time
>> table
>>> creation and it will fix? Not sure.
>>>
>>> and
>>>
>>> *UniformSplit
>>> <
>> https://hbase.apache.org/0.94/apidocs/org/apache/hadoop/hbase/util/RegionSplitter.UniformSplit.html
>>> *
>>>
>>>
>>>
>>> *Second 2: Does number of split point anywhere related to the number of
>> RS
>>> in cluster, If yes what is the calculation? *
>>>
>>
> 
> 

Mime
View raw message