When I read cassandra table every minute,it leave out some data,for example, suppose now is 2016-08-03 09:00:00 ,the table have 1000 rows data,but I only read 600 rows data.How can I solve the issue?There is no error message
Please check about Replication Factor (The number of replicas of data on multiple nodes) and Consistency Level.
Lets say you have configured a 4 node cassandra-cluster setup and configured Replication Factor as 3 for a key-space. Three copies of data will be available eventually for whatever data you insert. This is for resilience to any node's failure. In this setup, cassandra will function as normal even if one node down.
According to your need, you can configure consistency in cassandra. I suspect you using a low ready consistency here. You can try with read consistency as 'Quorum'.