我试图连接到我的系统Cassandra，但它给出了错误

Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})

我检查了日志文件，它给出了错误：

Batch of prepared statements for [test.connectors] is of size 82980, exceeding specified threshold of 51200 by 31780. (see batch_size_fail_threshold_in_kb)

但是我不知道如何纠正它