8 connections were created for every task

[bihluh]

Hi,

I have Source Database running in SQL Server. We have 10 databases inside this instance and it is a source server of Qlik replicate. I notice Qlik Replicate open 8 connections per replicate task. 

My concern is if I enabled replicate task for all 10 databases, it will generate 80 active connections in the database.. Is there a way to reduce the number of connections, like using connection Pool? 

Regards,

Bih Luh

[john_wang]

Hello @bihluh ,

Thanks for reaching out.

You are right. The maximum total connections number for a single SQL Server source database is 

8 + 4*N

Where N is the "Maximum number of tables" in task setting.

4*N connections are used for Full Load stage.

8 connections are used for CDC stage. After the Full Load done, the 4*N connections are released, the 8 connections are kept during the task running. These 8 connections are used for different threads, eg some for LOB lookup, some for DATA lookup, and some for metadata etc. I'm afraid there is no way to reduce the connections number in current versions, it's by design.

We'd like to suggest PS team engaged if all the 10 databases act as source database in parallel.

Hope this helps.

Regards,

John.

[MoeyE]

Hi John,

Does this include logstream tasks? For example if I left one logstream task running on CDC mode, it should only have 8 connections open. 

Is the 8 + (4 * N) connections relevant to other source database types as well? for example Oracle? Postgres?

Regards,

Mohammed

[john_wang]

Good morning Mohammed, @MoeyE ,

As LogStream tasks are used for CDC stage only, it should only have 8 connections open.

You are right, the connections number depends on the source database types. In general it's among (4 + 2*N) and 8 + (4*N), For SQL Server source, the maximum connections number of FL and CDC are 8 + (4*N).

Hope this helps.

John.

[MoeyE]

Hi John,

Yes, thanks for the info.

Regards,

Mohammed