Hi Michael,
The connection retain mode property makes the numbers almost same, but I
am a little confused. Shouldnt this be the default behavior of Entity Manager?
Typically I would have the entity manager tied up to the transaction (JTA or
Spring), so I would expect Entity Manager to hold the connection always.
Thanks and Regards,
Nitish Kumar
-----Original Message-----
From: Michael Dick [mailto:michael.d.d...@gmail.com]
Sent: Sat 3/21/2009 1:55 AM
To: users@openjpa.apache.org
Subject: Re: Slow performance with OpenJPA when selecting from a ManyToMany
relation.
Hi all,
As Paul pointed out privately I didn't indicate which versions of OpenJPA I
was using. I've been testing with 1.2.0, 1.2.1 and 2.0.0-SNAPSHOT primarily.
I also ran with 1.3.0-SNAPSHOT, and 1.0.3 for comparison - there wasn't much
difference though so reduced the scope to 1.2 and trunk.
The testcase uses a single EntityManager instance to issue a batch of findBy
operations. In OpenJPA each findBy (or any query for that matter) obtains a
connection from the connection pool and returns it after getting the
results. So we're spending a lot of time moving the connection to and from
the pool (some cleanup is done along the way).
Fortunately this behavior can be configured with the
openjpa.ConnectionRetainMode property. Setting it to "always" causes the
EntityManager to hold on to a single connection until the EntityManager
closes. Obviously this setting introduces the possibility of exhausting the
connection pool if num_entitymanagers > max_connections, but for this
benchmark it's safe to try.
Setting ConnectionRetainMode gave OpenJPA equivalent times on my laptop at
100 - 100,000 iterations. In addition I removed the
openjpa.jdbc.SynchronizeMappings property from the example (it's extraneous
once the tables are created anyway).Another option I enabled that made some
difference was preparedStatementCaching in dbcp. I'm assuming EclipseLink
has some pstmt caching as well, but that could be faulty - in which case
I'll disable it in dbcp.
Here's the entire set of properties I'm using :
properties.put("openjpa.Log", "DefaultLevel=FATAL");
properties.put("openjpa.RuntimeUnenhancedClasses", "unsupported");
properties.put("openjpa.ConnectionRetainMode", "always");
properties.put("openjpa.ConnectionDriverName",
"org.apache.commons.dbcp.BasicDataSource");
properties.put("openjpa.ConnectionProperties", String.format(
"DriverClassName=%s, Url=%s, username=%s, password=%s,"
+ " MaxActive=%s, MaxIdle=%s, MinIdle=%s, MaxWait=%s"
+ ", poolPreparedStatements=true"
, JDBC_DRIVER, JDBC_URL, JDBC_USER,
JDBC_PASSWORD, MAX_CON, MIN_CON, MIN_CON, "1000"));
EntityManagerFactory factory =
Persistence.createEntityManagerFactory("OpenJPAPU", properties);
MIN_CON = 1, MAX_CON=10.
Shubbis, could you try running something similar and see if you get the same
results?
-mike
On Fri, Mar 20, 2009 at 8:46 AM, Michael Dick <michael.d.d...@gmail.com>wrote:
> Hi, I took a quick run with the source code from the RAR Shubbis attached
> earlier (thanks BTW).
>
> The SQL we execute for this findBy is SELECT t0.warehouseName FROM
> Warehouse t0 WHERE t0.warehouseNr = ?. Pretty basic, and I doubt EclipseLink
> is doing better (certainly not 3x) based solely on the SQL.
>
> So I started digging deeper and on my laptop (not to be confused with any
> sort of "real" benchmark) there's a sweet spot around 100 iterations. Under
> 100 OpenJPA is faster. Between 100 and 125 they're comparable, and over 125
> iterations EclipseLink starts pulling ahead.
>
> Environment :
> * Entities were enhanced by the PCEnhancer tool prior to running the tests.
>
> * Connection pooling is enabled for EclipseLink and OpenJPA with roughly
> the same settings. EclipseLink's pool and commons-dbcp weren't an easy 1:1
> match, so I might have some investigation to do there.
> * MySQL Connector for Java v 5.1.7.
> * MySQL database running locally, Version: 5.0.67-0ubuntu6
> * Tests executed in Eclipse, YMMV outside of Eclipse.
> * Sun JDK 5 java full version "1.5.0_15-b04"
>
> I have done a lot of hacking about with the sample application but I don't
> think I've violated the intent of the exercise. I'll upload the app to a
> jira shortly.
>
> The relevant code is in my pastebin at these links :
> persistence.xml : http://miked.pastebin.com/m490814b7
> test01.java : http://miked.pastebin.com/m7d3df62f
> WarehouseDAO.java : http://miked.pastebin.com/m49ab9a0e
>
> I highlighted the changed lines in WarehouseDAO, but missed it on the
> others (too many lines to highlight accurately.
>
> I'm still looking, but thought this was worth sharing in case someone else
> sees something I've missed.
>
> -mike
>
>
>
> On Thu, Mar 19, 2009 at 10:53 AM, Paul Copeland <t...@jotobjects.com>wrote:
>
>>
>> At one point in this thread it was mentioned that the benchmark ran much
>> faster on a home computer than on an office computer and the reason for the
>> difference was not obvious. Was that difference explained yet?
>>
>> What version of OpenJPA is the test using?
>>
>> - Paul
>>
>>
>> On 3/19/2009 7:44 AM, Kevin Sutter wrote:
>>
>>> Shubbis and Nitish,
>>> Thanks for your efforts. So, to clarify -- all implementations are using
>>> similar configurations (ie. connection pooling, caching, enhancement,
>>> etc)?
>>> But, the OpenJPA performance is still 3 times slower than the
>>> competitors?
>>> In all of the scenarios? Or, just with this ManyToMany scenario? I
>>> would
>>> expect some overhead as compared to iBatis and/or straight JDBC, but
>>> OpenJPA
>>> should be competitive (and beat) the Hibernates and EclipseLinks... Very
>>> frustrating. When we do our comparisons with the industry benchmarks
>>> (Trade
>>> and SpecJApp), OpenJPA is extremely competitive.
>>>
>>> I have not closely examined your benchmark project, so I don't know how
>>> it
>>> compares to Trade and/or SpecJApp work loads. Any thoughts on this
>>> topic?
>>>
>>> One other thought... Just to prove that the enhancement processing is
>>> being
>>> done and you're not falling into the sub-classing support, could you run
>>> with the following property? This will cause your application to
>>> error-off
>>> if your Entities are not byte-code enhanced. We will not fall into the
>>> sub-classing support which greatly affects the performance.
>>>
>>> <property name="openjpa.RuntimeUnenhancedClasses"
>>> value="warn"/>
>>>
>>> It really seems that you are trying to do a fair comparison, and I
>>> greatly
>>> appreciate your efforts. The last time one of these comparisons was
>>> posted,
>>> the benchmark code and process was flawed. So, I am pleased to see the
>>> efforts associated with this exercise.
>>>
>>> Our performance lead is out having a baby, so we haven't been able to dig
>>> into your benchmark to the extent that we would like. If we can verify
>>> that
>>> the enhancement processing is happening, that would be good input.
>>> Thanks
>>> for your patience. What kind of timeframe are you under for posting this
>>> benchmark?
>>>
>>> Thanks,
>>> Kevin
>>>
>>> On Thu, Mar 19, 2009 at 9:05 AM, Shubbis <marius.jo...@broadpark.no>
>>> wrote:
>>>
>>>
>>>
>>>> Since we decided to go with vanilla installations of alle the frameworks
>>>> we
>>>> have not added the connection pool feature to OpenJPA, until now.
>>>>
>>>> The results are sadly not that great. Yes, it's faster and it doesn't
>>>> run
>>>> out of connections like before, BUT it's still 3, yes, -three- times
>>>> slower
>>>> than Hibernate, EclipseLink, iBatis and regular JDBC when persisting
>>>> entities with many relations.
>>>>
>>>> Clearly this is not the kind of results I was hoping for and I'm quite
>>>> perplexed as to what to do.
>>>>
>>>> Shubbis
>>>>
>>>>
>>>> Nitish Kumar wrote:
>>>>
>>>>
>>>>> Hi subbis,
>>>>> If I let the iteration loop over 5000, I get that exception, It
>>>>> seems (I am not sure) openjpa is creating a new connection and after a
>>>>> while mysql runs out of connection. I tried the same code and iteration
>>>>> loop with a connection pool and it works fine. That should get you
>>>>> moving as of now, till someone from Open JPA team looks into the issue.
>>>>>
>>>>> Thanks and Regards,
>>>>> Nitish Kumar
>>>>>
>>>>>
>>>>>
>>>> --
>>>> View this message in context:
>>>>
>>>> http://n2.nabble.com/Slow-performance-with-OpenJPA-when-selecting-from-a-ManyToMany-relation.-tp2466994p2503084.html
>>>> Sent from the OpenJPA Users mailing list archive at Nabble.com.
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>
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