As the increase of genome database size, there are increasing number of methods for detecting sequence similarity and increasing demands for genome sequence search and alignment services. It is a challenge to scale up the computer systems for serving these demands in a timely manner. This paper tackles this problem from a novel perspective, which treats the sequence search requests as content requests to both genome databases and similarity detection methods; therefore, scaling up the computer systems that serve these contents is a process of constructing content distribution network. The paper gives a decentralized method to construct content distribution network for a variety of genome sequence similarity detection services. It also gives a scheduling algorithm for efficiently using content nodes. Our simulation results show that scalability and high content node utilization can be achieved in such a system while the costs of achieving these are controllable.