Soheil, As Jeff mentioned that you need to provide more information. There are no known issues that I can think of that would cause such behavior. It would be great if you could provide us with a reduced test case so we can try and reproduce this behavior or at least help you debug the issue better. Could you detail the version of Cassandra, the number of nodes, the keyspace definition, RF / CL, perhaps a bit of your client code that does the writes, did you get back any errors on the client or on the server side? These details would be helpful to further help you. Thanks, Dinesh
On Saturday, April 21, 2018, 11:06:12 AM PDT, Soheil Pourbafrani <soheil.i...@gmail.com> wrote: I consume data from Kafka and insert them into Cassandra cluster using Java API. The table has 4 keys including a timestamp based on millisecond. But when executing the code, it just inserts 120 to 190 rows and ignores other incoming data! What parts can be the cause of the problem? Bad insert code in key fields that overwrite data, improper cluster configuration,....?