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From Batyrshin Alexander <0x62...@gmail.com>
Subject Re: Delay between put from HBase shell and result in SELECT from Phoenix
Date Fri, 25 Aug 2017 17:14:16 GMT
Its coming from scan time ragne. If i run sqlline with 'currentSCN' from the future then select
retrieve fresh data immediatly. 

We already have software that write with HBase API. Now we build client that works with data
from HBase via Phoenix.


> On 25 Aug 2017, at 19:35, Josh Elser <elserj@apache.org> wrote:
> 
> Calls to put in the HBase shell, to the best of my knowledge, are synchronous. You should
not have control returned to you until the update was committed by the RegionServers. HBase's
data guarantees are that once a call to write data returns to you, all other readers *must*
be able to see that update.
> 
> I'm not sure where this 3-5 second delay you describe is coming form.
> 
> Regardless, why are you writing data to HBase directly and circumventing the APIs to
write data via Phoenix? If you want to access your data via Phoenix, you're going to run into
less pain if you work completely at the Phoenix API level, (tl;dr use UPSERT to write data)
> 
> On 8/24/17 2:58 PM, Batyrshin Alexander wrote:
>> Here is example:
>> CREATE TABLE IF NOT EXISTS test (
>>   k VARCHAR NOT NULL,
>>   v VARCHAR,
>>   CONSTRAINT my_pk PRIMARY KEY (k)
>> );
>> 0: jdbc:phoenix:> upsert into test(k,v) values ('1', 'a');
>> 1 row affected (0.042 seconds)
>> 0: jdbc:phoenix:> select * from test;
>> +----+----+
>> | K  | V  |
>> +----+----+
>> | 1  | a  |
>> +----+----+
>> Then:
>> hbase(main):014:0> put 'TEST', '1', '0:V', 'b'
>> 0 row(s) in 0.0100 seconds
>> Result in phoenix will be available after ~ 3-5 seconds:
>> 0: jdbc:phoenix:> select * from test;
>> +----+----+
>> | K  | V  |
>> +----+----+
>> | 1  | a  |
>> +----+----+
>> 1 row selected (0.015 seconds)
>> ... 5 seconds later
>> 0: jdbc:phoenix:> select * from test;
>> +----+----+
>> | K  | V  |
>> +----+----+
>> | 1  | b  |
>> +----+----+
>> 1 row selected (0.026 seconds)
>>> On 24 Aug 2017, at 21:38, Batyrshin Alexander <0x62ash@gmail.com <mailto:0x62ash@gmail.com>
<mailto:0x62ash@gmail.com <mailto:0x62ash@gmail.com>>> wrote:
>>> 
>>>  Hello,
>>> 
>>> How to decrease or even eliminate delay between direct HBase put (for example
from HBase shell) and SELECT from Phoenix?
>>> 
>>> My table has only 1 VERSION and do not use any block cache ( {NAME => 'invoice',
COMPRESSION => 'LZO', BLOCKCACHE => 'false'} ), so i do not understand where previous
value for SELECT come from.


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