Meeting notes 11/13/2017

[divega]

Attendees: @anpete, @divega, @geleems, @sebastienros, @vancem

In today's meeting @vancem described an investigation the did several months ago of the TechEmpower Fortunes benchmark using SqlClient. Thanks for all the great information!

Here is a summary of his findings:

We are CPU bound. Thus it is about removing CPU overhead.

Recommendations:

1. More efficient building of HTML string.
   Option 1) Improve StringBuilder to avoid copies.
   i. Define a StringBuilder.ForeachChunk(Func<Span>) to characters from a StringBuilder without making a large string (e.g. ToString()).
   ii. Allow StringBuilder.Append(int) to take a CultureInfo so that string writing can be done without making a string)
   Option 2) (Larger) Make a UTF8String based StringBuilder and use that. (e.g. System.Text.Primitives).

2. (4%) There are hot locks in system.data.sqlclient
   a. (2.7%) system.data.sqlclient!System.Data.ProviderBase.DbConnectionPool.PrepareConnection
   b. (.3%) system.data.sqlclient!System.Data.SqlClient.SqlConnection+OpenAsyncRetry.Retry
   c. (.5%) system.private.corelib!System.Threading.TimerQueueTimer.Change

3. In general optimize system.private.corelib!System.Threading.TimerQueueTimer.Change

4. Converting to Unicode when deserializing from the database.

5. Change benchmark to use Ordinal Sorting (today it uses culture aware)?

6. Fix system.data.sqlclient!System.Data.ProviderBase.DbConnectionPoolIdentity.GetCurrent on windows to cache the windows identity, or to mimic what Linux does. (10%)

[divega]

@saurabh500 @geleems this is relevant to the discussion we had today.

[saurabh500]

Thanks @divega