使用java模拟多个用户连接到Cassandra

Question

I'm developing an application using java. The objective is to simulate multiple users connection to Cassandra (concurrent connections), all of them connected to same cluster.

My questions is: Should I implement multiple sessions where each session simulate a user. or only one session for the whole application.? Also how to implement multiple sessions if possible.?

Its appreciated if there is a reference or examples.

Answer 1

You should always consider using a single session with a connection pool for concurrent requests. you can build a retry mechanism if the session goes bad. having said that you can technically create redundant sessions, the driver would allow it.

Answer 2

Ideally, you should use only one Cluster / Session object per application, as each Session object creates a pool of connections to every node of the cluster + a control connection to get notifications about schema & topology changes, etc., and having too many connections would add an additional load to the nodes. As described in the documentation , single network connection could carry on multiple requests simultaneously, and you can increase the number of the in-flight requests if you need, but it's not recommended to set them too high, as the high number of in-flight requests is a sign that nodes aren't able to execute queries so fast - this could happen if you're running queries that use ALLOW FILTERING , or fetching too much data.

You can find more information in the DataStax's guide " Developing applications with DataStax drivers ".