Timeout expired. Max pool size was reached

Question

Hopefully someone can assist me on a error I am getting. I have a batch macro, which gets a file URL as input. There are around 300 csv files. The macro appends the records into a Azure SQL DataWarehouse table, using the SQL Server Bulk Connection. It works fine for the first around 130 records, before giving this error: (119) Record #131: Tool #11: bcp_sendrow failed: [Microsoft][SQL Server Native Client 11.0][SQL Server]Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached. The subsequent macro iterations get the following error: (119) Record #132: Tool #11: Error opening "SELECT * FROM """: No Columns Returned. I tried (desperately) to set "max pool size=200" in the output data tool connection string, but it does not seem to change anything. Anyone who have encountered this before, and/or have any idea how to remedy it?

DanM · Accepted Answer

We currently don't have a way to set the pool size with the SQL Server Bulk Connection.  At this time, the only work around would be to close the module and restart the process to free the SQL Server Connections. We will be looking to build a feature to be able to adjust this in a future release.