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From Mujtaba Chohan <mujt...@apache.org>
Subject Re: Phoenix has slow response times compared to HBase
Date Sat, 03 Sep 2016 00:40:28 GMT
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.
>

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