Thanks for using Syncfusion products.
Regarding your query "While doing spark operations in scala,the application is very slow and hangs", can you confirm whether your operating system is Windows 10? If yes, please try the following and let us know that issue gets resolved at your end.
Letters slowly getting typed scenario in Spark-Scala console occurs only in Windows 10 operating system. On checking the same, we would suggest to upgrade “jline” jar to latest version(2.14.6) in your Spark package.
Step 2: Stop all the services via 'Local Service Manager'
Step 3: Replace the downloaded jar “jline-2.14.6” instead of already existing “jline-2.12.1” in Spark Jars folder(..\Syncfusion\BigData\18.104.22.168\BigDataSDK\SDK\Spark\jars\jline-2.12.1).
Step 4: Now start the services and make use of scala/pyspark. (Refer below screenshot)
Please let us know, if you have any other concerns.
Dinesh Kumar P