QoS-based service selection has been an active research area in both Service Computing and Cloud Computing communities in recent years. One of the obstacles for many researchers is lack of benchmark QoS datasets, especially for cloud service selection. In this paper, we propose a testbed system which can be used to collect the QoS data for software services hosted in the cloud. We mainly focus on analytic services, whose QoS values could be dependent on the data they are used to process and analyze. Using the testbed, we can publish services (software or infrastructure services), we can invoke software services hosted on certain infrastructure services, and system can monitor and record the QoS values of all the invocations. We have implemented a proof-of-concept prototype system and used it to collect a sample QoS dataset.