Hello, Kevin. The implementation with pooling of EntityManager instances is much faster. With this implementation performance loss on PostgreSQL is less than 10%, on MySql between 12-22% for web application which i test.
Best regards Georgi Georgi Naplatanov wrote: > Hello, Kevin, thank you for ideas. > > I didn't think to pool EntityManager instances. I definitely will try it. > > Best regards > Georgi > > Kevin Sutter wrote: >> Georgi, >> One of the first areas I would look at is the creation and destruction of >> the EntityManagers. You mention that you are running with an extended >> context, but does the application create or pool EntityManagers? Although >> our testing has been with IBM databases, we have found that we get the best >> performance with the minimum number of EntityManager creations. If you can >> clear and reuse the EntityManagers, the overall performance will be better. >> >> There is another cache that helps with sql generation as well. It has a >> couple of restrictions, but if the majority of your queries are simple >> findby operations, this cache will help considerably. The property is >> QuerySQLCache and it is documented in the OpenJPA 1.2.x manual ( >> http://openjpa.apache.org/builds/1.2.0/apache-openjpa-1.2.0/docs/manual/manual.html#ref_guide_cache_querysql >> ). >> >> Hope this helps with getting better performance. >> >> Kevin >> >> On Mon, Aug 25, 2008 at 3:21 PM, Georgi Naplatanov <[EMAIL PROTECTED]> wrote: >> >>> Hello, >>> >>> I'm porting SQL/JDBC web application to JPA and i made some performance >>> tests with PostgreSQL 8.3.3 and MySql 5.0.51a Community edition, with >>> both - SQL/JDBC and OpenJPA implementations of the application. >>> >>> Apache ab Apache Jmeter >>> PostgreSQL 8.3 -15% -12% >>> MySql 5.0.51a -64% -27% >>> >>> On both tests on PostgreSQL the performance loss is about 15% compared >>> to pure SQL/JDBC implementation. >>> >>> On MySql the performance loss is very big especially on test with Apache >>> ab utility. >>> >>> In the tests, OpenJPA 1.2.0 is configured with data cache enabled, query >>> data cache disabled and query compilation cache - enabled. OpenJPA >>> operates in extended context with Apache DBCP and statement pooling. >>> >>> Is this performance loss on MySql normal ? Does OpenJPA require some >>> special configuration for MySql ? >>> >>> It is my persistence.xml file. >>> >>> <property name="openjpa.ConnectionProperties" >>> value="DriverClassName=com.mysql.jdbc.Driver, >>> Url=jdbc:mysql://localhost/mydb, >>> Username=root, >>> Password=123, >>> maxActive=25, >>> maxWait=25, >>> minIdle=3, >>> maxIdle=25, >>> whenExhaustedAction=block, >>> testOnBorrow=false, >>> testWhileIdle=true, >>> timeBetweenEvictionRunsMillis=3600000, >>> numTestsPerEvictionRun=3, >>> minEvictableIdleTime=1800000, >>> testQuery=select 1, >>> poolPreparedStatements=true"/> >>> <property name="openjpa.ConnectionDriverName" >>> value="org.apache.commons.dbcp.BasicDataSource"/> >>> >>> <property name="openjpa.QueryCompilationCache" value="true"/> >>> <property name="openjpa.QueryCache" value="false"/> >>> <property name="openjpa.RemoteCommitProvider" value="sjvm"/> >>> <property name="openjpa.DataCache" value="true(CacheSize=2000, >>> SoftReferenceSize=0)"/> >>> <property name="openjpa.FetchBatchSize" value="100"/> >>> <property name="openjpa.ConnectionRetainMode" value="on-demand"/> >>> <property name="openjpa.FlushBeforeQueries" value="true"/> >>> <property name="openjpa.jdbc.DBDictionary" >>> >>> value="org.apache.openjpa.jdbc.sql.MySQLDictionary(SupportsSubselect=true)"/> >>> >>> Best regards >>> Georgi >>> > >
