Re: [Firebird-net-provider] Firebird scalability under heavy load

[pablosantosluac <pab...@te...>]

Hi Carlos,

I've just run our test again using Firebird backend. The table below =
shows the profiler results for a test with a server (embedded) working =
with 20 simultaneous clients, so there's a lot of concurrency.


      Routine Name Module Name % Time % with Children Time Time with =
Children Shared Time Hit Count=20
      FesStatement::Fetch FirebirdSql.Data.Firebird.dll 18,57% 3,55% =
2679,05 7806,72 34,32 1240193=20
      FesStatement::Free FirebirdSql.Data.Firebird.dll 8,40% 0,56% =
1211,19 1225,23 98,85 660413=20
      XsqldaMarshaler::MarshalManagedToNative =
FirebirdSql.Data.Firebird.dll 6,66% 0,80% 960,1 1749,81 54,87 1617581=20
      XsqldaMarshaler::MarshalNativeToManaged =
FirebirdSql.Data.Firebird.dll 6,51% 1,39% 939 3059,23 30,69 1563064=20
      GlobalizationHelper::CultureAwareCompare =
FirebirdSql.Data.Firebird.dll 3,74% 0,25% 539,87 539,87 100 30454745=20
      XsqldaMarshaler::GetString FirebirdSql.Data.Firebird.dll 3,16% =
0,31% 455,28 684,84 66,48 33472568=20
      XsqldaMarshaler::CleanUpNativeData FirebirdSql.Data.Firebird.dll =
3,11% 0,24% 448,06 528,05 84,85 2883890=20
      FesStatement::GetSqlInfo FirebirdSql.Data.Firebird.dll 2,34% 0,16% =
337,8 343,18 98,43 280302=20
      DbField::GetDbDataType FirebirdSql.Data.Firebird.dll 2,22% 0,22% =
319,82 490,04 65,26 39600463=20
      FesStatement::Execute FirebirdSql.Data.Firebird.dll 1,92% 0,16% =
277,65 351,86 78,91 660413=20
      FesTransaction::Commit FirebirdSql.Data.Firebird.dll 1,89% 0,12% =
272,31 273,31 99,64 13028=20
      XsqldaMarshaler::ComputeLength FirebirdSql.Data.Firebird.dll 1,88% =
0,12% 271,28 271,28 100 35290780=20
      Descriptor::get_Item FirebirdSql.Data.Firebird.dll 1,88% 0,12% =
270,46 270,46 100 221582569=20
      FbDataReader::GetOrdinal FirebirdSql.Data.Firebird.dll 1,83% 0,42% =
263,55 919,09 28,67 6088214=20
      FesStatement::Prepare FirebirdSql.Data.Firebird.dll 1,58% 0,59% =
228,24 1291,67 17,67 197368=20
      XsqldaMarshaler::MarshalManagedToNative =
FirebirdSql.Data.Firebird.dll 1,50% 0,13% 217,06 295,26 73,52 1617581=20



Ok, the first two methods (Fetch & Free) eat about 26% of the test time =
and they're basically spending their times at FbClient.isc_dsql_fetch =
and FbClient.isc_dsql_free_statement.

It looks like Marshaling and Unmarshaling data is taken a long time, I'd =
say even longer than the "internal" calls themselves.

On the other hand, in my test, the embedded server is slower than the =
"external" one: 444s to complete the embedded vs 291 the "external". =
Just to give some data to compare: using SQL Server the same test =
(exactly the same code base) requires 198 seconds. The interesting thing =
is that the test with only one client (instead of 20) is faster with the =
Fb backend than the SQL Server one. Maybe it is not an issue with the =
provider but firebird itself, although the time taken to marshal and =
unmarshal looks like a possible "culprit".


But, running exactly the same test against an external server I get the =
following:
      Routine Name Module Name % Time % with Children Time Time with =
Children Shared Time Hit Count=20
      XdrStream::Read FirebirdSql.Data.Firebird.dll 37,98% 2,28% 3573,73 =
3690,01 96,85 31677462=20
      FbDataReader::GetOrdinal FirebirdSql.Data.Firebird.dll 3,38% 0,41% =
318,18 655,04 48,57 6072788=20
      XdrStream::Write FirebirdSql.Data.Firebird.dll 2,27% 0,23% 213,13 =
375,04 56,83 12712555=20
      DbField::GetDbDataType FirebirdSql.Data.Firebird.dll 2,05% 0,18% =
192,56 290,64 66,25 15044218=20
      XdrStream::Flush FirebirdSql.Data.Firebird.dll 1,98% 0,12% 186,07 =
190,78 97,53 2740818=20
      GlobalizationHelper::CultureAwareCompare =
FirebirdSql.Data.Firebird.dll 1,94% 0,11% 182,78 182,78 100 30456311=20



I don't know whether there is any possible optimization at the =
provider's level.

Thanks,


pablo

  ----- Original Message -----=20
  From: Carlos=20
  To: For users and developers of the Firebird .NET providers=20
  Sent: Friday, December 28, 2007 11:16 AM
  Subject: Re: [Firebird-net-provider] Firebird scalability under heavy =
load


  Hello:




    Ok, so, you mean I should try with the new 2.0+ provider? I mean, we =
are having the same problems with the "server" (not the=20


    embedded one).


  Well no, it maybe a problem on it, but we may try to check where is =
the problem ( the 2.0+ has performance changes on other areas as well, =
but anyway, we should check first where is the real problem )=20
  =20


  --=20
  Carlos Guzm=C3=A1n =C3=81lvarez
  Vigo-Spain=20


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