A method comprising: receiving, by a Content Delivery Network, CDN, node, configuration information from a global control center; determining a type of the CDN node from multiple types of CDN nodes based on the configuration information, wherein the multiple types of CDN nodes include a relay node and an access node; conducting, by the CDN node, route exploration between the CDN node and one or more other CDN nodes based on the type of the CDN node to obtain one or more respective exploration values; and in response to a determination that the CDN node receives an access request from a user to a domain desired for dynamic acceleration, determining, for each of multiple return-to-source routing paths of the CDN node, a respective path value of the respective return-to-source routing path; and selecting one of the return-to-source routing paths based on the path values to perform a return-to-source operation to obtain content from a source station of the domain; wherein the determining the respective path value a respective one of the return-to-source routing paths includes: multiplying a respective exploration value between an access node and a relay node by a first weight; multiplying a respective exploration value between two adjacent relay nodes by a second weight; and multiplying a respective exploration value between a source station and a relay node by a third weight; and adding corresponding values together to obtain the respective path value of the respective one of the return-to-source routing paths. receiving, by a Content Delivery Network, CDN, node, configuration information from a global control center; determining a type of the CDN node from multiple types of CDN nodes based on the configuration information, wherein the multiple types of CDN nodes include a relay node and an access node; conducting, by the CDN node, route exploration between the CDN node and one or more other CDN nodes based on the type of the CDN node to obtain one or more respective exploration values; and in response to a determination that the CDN node receives an access request from a user to a domain desired for dynamic acceleration, determining, for each of multiple return-to-source routing paths of the CDN node, a respective path value of the respective return-to-source routing path; and selecting one of the return-to-source routing paths based on the path values to perform a return-to-source operation to obtain content from a source station of the domain; determining, for each of multiple return-to-source routing paths of the CDN node, a respective path value of the respective return-to-source routing path; and selecting one of the return-to-source routing paths based on the path values to perform a return-to-source operation to obtain content from a source station of the domain; wherein the determining the respective path value a respective one of the return-to-source routing paths includes: multiplying a respective exploration value between an access node and a relay node by a first weight; multiplying a respective exploration value between two adjacent relay nodes by a second weight; and multiplying a respective exploration value between a source station and a relay node by a third weight; and multiplying a respective exploration value between an access node and a relay node by a first weight; multiplying a respective exploration value between two adjacent relay nodes by a second weight; and multiplying a respective exploration value between a source station and a relay node by a third weight; and adding corresponding values together to obtain the respective path value of the respective one of the return-to-source routing paths. <EOS>