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From Mujtaba Chohan <mujt...@apache.org>
Subject Re: Phoenix has slow response times compared to HBase
Date Thu, 22 Sep 2016 17:32:38 GMT
Hi Edu,

See the attached updated test which initialize Phoenix before running the
concurrent test to mimic real world usage where JVM should not be restarted
before each run. Apart from this it runs 2 queries per thread without
ignoring time for the first query and the average time still remain within
few ms.

-mujtaba


On Wed, Sep 7, 2016 at 2:00 PM, James Taylor <jamestaylor@apache.org> wrote:

> Thanks for the update, Edu. Mujtaba is out of the office for the next
> couple of weeks, so unless someone else has time to pick this up, it likely
> won't be picked up until he returns.
>
>      James
>
> On Mon, Sep 5, 2016 at 8:36 AM, Narros, Eduardo (ELS-LON) <
> e.narros@elsevier.com> wrote:
>
>> Hi Mujtaba,
>>
>>
>> Thanks a lot for helping us to get to the bottom of this. Looking at your
>> test code we have observed that you are ignoring the execution time of the
>> first query. If we do the same, our results are similar to yours.
>>
>>
>> Unfortunately, our tests cannot ignore the time it takes to fetch a
>> record by a thread for the first time. We are interested in the response
>> times for the first and second queries per thread. (i.e. each thread just
>> runs 2 queries)
>>
>>
>> When we rerun your code without ignoring the first result and with the
>> number of runs per thread equal 2, we see similar results to our original
>> findings. We have attached our modified test harness to this email.
>>
>>
>> Kind Regards,
>>
>>
>> Edu
>>
>>
>> ------------------------------
>> *From:* Mujtaba Chohan <mchohan@salesforce.com>
>> *Sent:* 03 September 2016 02:06:30
>> *To:* user@phoenix.apache.org
>> *Subject:* Re: Phoenix has slow response times compared to HBase
>>
>> Single user average: Phoenix 8ms, HBase 5ms
>> 50 users average: Phoenix 35ms, HBase 40ms
>> 500 users average: Phoenix 300-400ms, HBase 350-450ms
>>
>> Few notes:
>>
>> * We have yet to identify why Phoenix was showing slight advantage with
>> high number of concurrent users from single client.
>>
>> * For the case with 500 concurrent users from single client, region
>> server handler count and Phoenix thread pool size was bumped to 500 to
>> accommodate this level of concurrency.
>>
>> On Friday, September 2, 2016, James Taylor <jamestaylor@apache.org>
>> wrote:
>>
>>> Thanks, Mujtaba. What's the average query time for HBase and Phoenix for
>>> the 1/50/500 simultaneous user scenarios?
>>>
>>> Edu - make sure to set the UPDATE_CACHE_FREQUENCY property on the table
>>> (as Mujtaba showed in his ALTER TABLE statement - you can do this in the
>>> CREATE TABLE statement as well).
>>>
>>> Thanks,
>>> James
>>>
>>> On Fri, Sep 2, 2016 at 5:40 PM, Mujtaba Chohan <mujtaba@apache.org>
>>> wrote:
>>>
>>>> Here is the graph that I get simulating 1, 50 and 500 concurrent users
>>>> from single client. Query time for Phoenix is highly comparable with direct
>>>> HBase gets.
>>>>
>>>> See the chart below with query time (ms) for random point gets over
>>>> large table that will not fit HBase block cache. Query/gets were executed
>>>> for 1000 time for each user.
>>>>
>>>> [image: Inline image 1]
>>>> Source code to execute gets/phoenix query simulating multiple users is
>>>> at:
>>>> ​
>>>>  directhbasemt.java
>>>> <https://drive.google.com/file/d/0B0AJDm160pciTVlhSzU3aWtrNW8/view?usp=drive_web>
>>>> ​​
>>>>  directphoenixmt.java
>>>> <https://drive.google.com/file/d/0B0AJDm160pciYkw4SzNVQy1meHM/view?usp=drive_web>
>>>> ​
>>>> Table DDL
>>>> create table testuuid (k varchar not null primary key, a varchar, b
>>>> varchar, c varchar, d varchar, e varchar, f varchar);
>>>>
>>>> alter table testuuid set "UPDATE_CACHE_FREQUENCY"=150000; // this
>>>> restricts how often server will check for metadata updates to improve
>>>> performance
>>>>
>>>> Table was filled with 68M rows.
>>>> Phoenix 4.8/HBase 0.98.17 running on single machine.
>>>>
>>>> //mujtaba
>>>>
>>>>
>>>> On Thu, Sep 1, 2016 at 3:34 AM, Narros, Eduardo (ELS-LON) <
>>>> e.narros@elsevier.com> wrote:
>>>>
>>>>> Hi Mujtaba,
>>>>>
>>>>>
>>>>> See the answers inline below:
>>>>>
>>>>>
>>>>> * How are you running Phoenix queries? *We are using apache-jmeter
>>>>> and the jdbc sampler.*
>>>>> * Were the concurrent Phoenix queries using the same JVM? *Yes.*
>>>>> * Was the JVM restarted after changing number of concurrent users?
>>>>> *Yes.*
>>>>> * Is the response time plotted when query is executed for the first
>>>>> time or second or average of both? *Average. We see response times
>>>>> ranging significantly even via sqlline. i.e. the same query run 11 times
>>>>> sequentially takes anything between 17ms to around 489ms with no other
load
>>>>> on the server.*
>>>>> * Is the UUID filtered on randomly distributed? *Yes.*
>>>>> * Does UUID match a single row? *Yes.*
>>>>> * It seems that even non-concurrent Phoenix query which filters on
>>>>> UUID takes 500ms in your environment. Can you try the same query in Sqlline
>>>>> a few times and see how much time it takes for each run?
>>>>> *We run the same query 11 times via sqlline and these were the
>>>>> response times: *
>>>>> *1 row selected (0.489 seconds)*
>>>>> *1 row selected (0.279 seconds)*
>>>>> *1 row selected (0.227 seconds)*
>>>>> *1 row selected (0.22 seconds)*
>>>>> *1 row selected (0.17 seconds)*
>>>>> *1 row selected (0.152 seconds)*
>>>>> *1 row selected (0.129 seconds)*
>>>>> *1 row selected (0.17 seconds)*
>>>>> *1 row selected (0.153 seconds)*
>>>>> *1 row selected (0.259 seconds)*
>>>>> *1 row selected (0.102 seconds)*
>>>>>
>>>>> * What is the explain <https://phoenix.apache.org/language/#explain>
>>>>> plan for your Phoenix query? *CLIENT 1-CHUNK PARALLEL 1-WAY ROUND
>>>>> ROBIN POINT LOOKUP ON 1 KEY OVER schema.DOCUMENTS*
>>>>> * If it's slow in Sqlline as well then try truncating your
>>>>> SYSTEM.STATS table and reconnect Sqlline and execute the query again.
*I
>>>>> think the issue is that the response times vary a lot, with 600 concurrent
>>>>> users the same query can take anything between 2ms to 10s.*
>>>>> * Can you share your table schema and how you ran Phoenix queries and
>>>>> your HBase equivalent code? *It is a simple table with 15 columns,
>>>>> the primary key is the uuid which is of type VARCHAR(36). The hbase
>>>>> equivalent code is:*
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> * HTableInterface hTable = pool.getTable("schema.DOCUMENTS");Get get
=
>>>>> new Get(toBytes(saltPrefix + uuid));Result result = hTable.get(get);
*
>>>>>
>>>>> * Any phoenix tuning defaults that you changed? *No.*
>>>>>
>>>>> Kind Regards,
>>>>>
>>>>>
>>>>> Edu
>>>>>
>>>>>
>>>>> On Wed, Aug 31, 2016 at 10:40 AM, Mujtaba Chohan <mujtaba@apache.org>
>>>>> wrote:
>>>>>
>>>>>> Something seems inherently wrong in these test results.
>>>>>>
>>>>>> * How are you running Phoenix queries? Were the concurrent Phoenix
>>>>>> queries using the same JVM? Was the JVM restarted after changing
number of
>>>>>> concurrent users?
>>>>>> * Is the response time plotted when query is executed for the first
>>>>>> time or second or average of both?
>>>>>> * Is the UUID filtered on randomly distributed? Does UUID match a
>>>>>> single row?
>>>>>> * It seems that even non-concurrent Phoenix query which filters on
>>>>>> UUID takes 500ms in your environment. Can you try the same query
in Sqlline
>>>>>> a few times and see how much time it takes for each run?
>>>>>> * If it's slow in Sqlline as well then try truncating your
>>>>>> SYSTEM.STATS
>>>>>> * Can you share your table schema and how you ran Phoenix queries
and
>>>>>> your HBase equivalent code?
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Wed, Aug 31, 2016 at 5:42 AM, Narros, Eduardo (ELS-LON) <
>>>>>> e.narros@elsevier.com> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>>
>>>>>>> We are exploring starting to use Phoenix and have done some load
>>>>>>> tests to see whether Phoenix would scale. We have noted that
compared to
>>>>>>> HBase, Phoenix response times have a much slower average as the
number of
>>>>>>> concurrent users increases. We are trying to understand whether
this is
>>>>>>> expected or there is something we are missing out.
>>>>>>>
>>>>>>>
>>>>>>> This is the test we have performed:
>>>>>>>
>>>>>>>
>>>>>>>    - Create table (20 columns) and load it with 400 million records
>>>>>>>    indexed via a column called 'uuid'.
>>>>>>>    - Perform the following queries using 10,20,100,200,400 and
600
>>>>>>>    users per second, each user will perform each query twice:
>>>>>>>       - Phoenix: select * from schema.DOCUMENTS where uuid =
?
>>>>>>>       - Phoenix: select /*+ SERIAL SMALL */* from schema.DOCUMENTS
>>>>>>>       where uuid = ?
>>>>>>>       - Hbase equivalent to: select * from schema.DOCUMENTS where
>>>>>>>       uuid = ?
>>>>>>>    - The results are attached and they show that Phoenix response
>>>>>>>    times are at least an order of magnitude above those of HBase
>>>>>>>
>>>>>>> The tests were run from the Master node of a CDH5.7.2 cluster
with
>>>>>>> Phoenix 4.7.0.
>>>>>>>
>>>>>>> Are these test results expected?
>>>>>>>
>>>>>>> Kind Regards,
>>>>>>>
>>>>>>> Edu
>>>>>>>
>>>>>>>
>>>>>>> ------------------------------
>>>>>>>
>>>>>>> Elsevier Limited. Registered Office: The Boulevard, Langford
Lane,
>>>>>>> Kidlington, Oxford, OX5 1GB, United Kingdom, Registration No.
1982084,
>>>>>>> Registered in England and Wales.
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> ------------------------------
>>>>>
>>>>> Elsevier Limited. Registered Office: The Boulevard, Langford Lane,
>>>>> Kidlington, Oxford, OX5 1GB, United Kingdom, Registration No. 1982084,
>>>>> Registered in England and Wales.
>>>>>
>>>>
>>>>
>>>
>> ------------------------------
>>
>> Elsevier Limited. Registered Office: The Boulevard, Langford Lane,
>> Kidlington, Oxford, OX5 1GB, United Kingdom, Registration No. 1982084,
>> Registered in England and Wales.
>>
>
>

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