One specific issue with Impala connection pool timeout error got resolved by increasing in Impala configuration in CM and then restarting Impala daemon:    fe_service_threads    from 64     =====> increased to 128 as per recommendation below. ------------------------------------------------------------------------------------------------------ Following are the recommended configuration setting for the best performance with Impala.  https://docs.cloudera.com/best-practices/latest/impala-performance/topics/bp-impala-recommended-configurations.html#:~:text=Set%20the%20%2D%2Dfe_service_threads%20startup,of%20concurrent%20client%20connections%20allowed.  Set the --fe_service_threads startup option for the Impala daemon (impalad) to 256. This option specifies the maximum number of concurrent client connections allowed. See Startup Options for impalad Daemon for details.    Below are the errors that got resolved by increasing Impala daemon pool size: --------------------------------------------------------------------------------------------------------- com.streamsets.pipeline.api.StageException: JDBC_06 - Failed to initialize connection pool: com.zaxxer.hikari.pool.PoolInitializationException: Exception during pool initialization: [Cloudera][ImpalaJDBCDriver](700100) Connection timeout expired. Details: None.    SQL Error [3] [S1000]: [Cloudera][ThriftExtension] (3) Error occurred while contacting server: ETIMEDOUT. The connection has been configured to use a SASL mechanism for authentication. This error might be due to the server is not using SASL for authentication.  ... View more