When the AtScale pool size is larger than the available connection in Admission Control, some queries might be unable to run due to an unavailable connection.
To resolve this, set the pool size equal to the Impala queue size.
- The AtScale engine operates via a connection pool, so we will not open and close the connection every time.
- The default pool size on the engine side is 20
- This means that the pool size should equal the size of the Impala queue. This way, for every connection the engine makes from the pool, there will be an available connection on the Impala side.