Thomas,
Should we be creating (opening) and closing a db connection every time
we want to execute a query?
Instead of having a single db entry point maintaining a single
connection... which gets opened and closed on the creation/destroy of
the object?
On Oct 8, 6:04 pm, vsaji <[EMAIL PROTECTED]> wrote:
> Thanks Thomas.
>
> I have identified the issue. I was using a single h2 db connection for
> all requests and after user I didn't close it.
>
> Feeling bit relax now :).
>
> public class H2Test{
>
> private final Connection con = getConnection();
>
> public ResultSet getData(){
> Statement st = con.createStateMent()
> ...............
>
> }
>
> public void update(){
> Statement st = con.createStateMent()
> ...............
>
> }
>
> public void insert(){
> Statement st = con.createStateMent()
> ...............
>
> }
> }
>
> Regards
> Saji
>
> On Oct 9, 3:48 am, "Thomas Mueller" <[EMAIL PROTECTED]>
> wrote:
>
> > Hi,
>
> > From what you describe, it could be a memory leak in the application.
> > Could you post the number without using "grep .h2."
> > But only a reproducible test case would show that.
>
> > Regards,
> > Thomas
>
> > On Wed, Oct 8, 2008 at 12:25 PM, vsaji <[EMAIL PROTECTED]> wrote:
>
> > > Hi Thomas,
>
> > > I could see the same topic has been posted earlier in this forum. I
> > > have tried those resolutions as well. However, no luck.
>
> > > My application is a stand-alone multi threaded application which use
> > > H2 in-memory DB to cache few records.
> > > Currently I am having 7 tables in this database and the avg of record
> > > count is 40 per table.
>
> > > The table gets accessed Max 100 times per second (only SELECT(98%) and
> > > INSERT(2%)). The behavior of the application is, it queries a source
> > > DB on every 5000 ms seconds and transforms the data using the cached
> > > value then stores to a target DB.
>
> > > If you look at the below histo (produced out of JMAP), every interval
> > > the memory consumption is going high and never comes down.
>
> > > I have tried keeping the CACHE_SIZE as 8192 and even tested with
> > > 1.0.79 (last stable version). No changes in the result.
>
> > > PLS HELP.
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 12: 14793 710064 org.h2.expression.ExpressionColumn
> > > 18: 1755 280800 org.h2.command.dml.Select
> > > 22: 12714 203424 org.h2.util.ObjectArray
> > > 26: 5134 177352 [Lorg.h2.value.Value;
> > > 28: 4833 154656 org.h2.expression.Comparison
> > > 30: 3582 143280 org.h2.expression.ExpressionVisitor
> > > 31: 1755 140400 org.h2.table.TableFilter
> > > 32: 1755 126360 org.h2.result.LocalResult
> > > 34: 2129 119224 org.h2.expression.Function
> > > 35: 4558 117208 [Lorg.h2.expression.Expression;
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 8: 16058 770784 org.h2.expression.ExpressionColumn
> > > 13: 1813 290080 org.h2.command.dml.Select
> > > 16: 11155 178480 org.h2.util.ObjectArray
> > > 17: 5552 177664 org.h2.expression.Comparison
> > > 20: 1813 145040 org.h2.table.TableFilter
> > > 21: 1858 133776 org.h2.jdbc.JdbcPreparedStatement
> > > 22: 1813 130536 org.h2.result.LocalResult
> > > 24: 3554 103616 [Lorg.h2.expression.Expression;
> > > 25: 1813 101528 org.h2.jdbc.JdbcResultSet
> > > 27: 1657 92792 org.h2.expression.Function
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 11: 21077 1011696 org.h2.expression.ExpressionColumn
> > > 18: 2447 391520 org.h2.command.dml.Select
> > > 22: 17076 273216 org.h2.util.ObjectArray
> > > 26: 7083 226656 org.h2.expression.Comparison
> > > 28: 2447 195760 org.h2.table.TableFilter
> > > 29: 2447 176184 org.h2.result.LocalResult
> > > 30: 4401 176040 org.h2.expression.ExpressionVisitor
> > > 31: 4842 171440 [Lorg.h2.value.Value;
> > > 33: 2348 169056 org.h2.jdbc.JdbcPreparedStatement
> > > 35: 2843 159208 org.h2.expression.Function
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 9: 29904 1435392 org.h2.expression.ExpressionColumn
> > > 15: 3362 537920 org.h2.command.dml.Select
> > > 16: 21262 340192 org.h2.util.ObjectArray
> > > 17: 10245 327840 org.h2.expression.Comparison
> > > 19: 3362 268960 org.h2.table.TableFilter
> > > 21: 3362 242064 org.h2.result.LocalResult
> > > 22: 3355 241560 org.h2.jdbc.JdbcPreparedStatement
> > > 26: 7105 200536 [Lorg.h2.expression.Expression;
> > > 28: 3414 191184 org.h2.expression.Function
> > > 29: 3362 188272 org.h2.jdbc.JdbcResultSet
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 5: 39956 1917888 org.h2.expression.ExpressionColumn
> > > 13: 4452 712320 org.h2.command.dml.Select
> > > 15: 27632 442112 org.h2.util.ObjectArray
> > > 16: 13718 438976 org.h2.expression.Comparison
> > > 17: 4452 356160 org.h2.table.TableFilter
> > > 18: 4460 321120 org.h2.jdbc.JdbcPreparedStatement
> > > 19: 4452 320544 org.h2.result.LocalResult
> > > 21: 9196 262872 [Lorg.h2.expression.Expression;
> > > 24: 4466 250096 org.h2.expression.Function
> > > 25: 4452 249312 org.h2.jdbc.JdbcResultSet
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 8: 50740 2435520 org.h2.expression.ExpressionColumn
> > > 13: 5708 913280 org.h2.command.dml.Select
> > > 16: 37196 595136 org.h2.util.ObjectArray
> > > 18: 17238 551616 org.h2.expression.Comparison
> > > 22: 5708 456640 org.h2.table.TableFilter
> > > 25: 5708 410976 org.h2.result.LocalResult
> > > 26: 5580 401760 org.h2.jdbc.JdbcPreparedStatement
> > > 28: 12852 352984 [Lorg.h2.expression.Expression;
> > > 29: 6258 350448 org.h2.expression.Function
> > > 32: 5708 319648 org.h2.jdbc.JdbcResultSet
>
> > > C:\app\jdk1.6.0\bin>jmap -histo 3488 | grep .h2. | head -10
> > > 1: 70720 3394560 org.h2.expression.ExpressionColumn
> > > 8: 7796 1247360 org.h2.command.dml.Select
> > > 13: 24344 779008 org.h2.expression.Comparison
> > > 14: 47127 754032 org.h2.util.ObjectArray
> > > 16: 7796 623680 org.h2.table.TableFilter
> > > 17: 7841 564552 org.h2.jdbc.JdbcPreparedStatement
> > > 18: 7796 561312 org.h2.result.LocalResult
> > > 19: 15560 452976 [Lorg.h2.expression.Expression;
> > > 21: 7796 436576 org.h2.jdbc.JdbcResultSet
> > > 22: 7657 428792 org.h2.expression.Function- Hide quoted text -
>
> > - Show quoted text -
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