| Besides text and pictures,video is becoming the primary choice for agricultural science and technology achievements exhibition as to its dynamics.At present,the video of agricultural scientific and technological achievements is stored in different institutions and units.Most of the agricultural video management platforms still use the traditional architecture and database,which led to a low efficiency of files retrieval and weak guarantee of the security access.As a result,the sharing and dissemination of agricultural science and technology achievements are limited.Therefore,this dissertation studies the architecture of video cloud storage,storage and retrieval methods of agricultural science and technology achievements.Then,a dual security access strategy based on role-rights and user identity is put forward.On this basis,the cloud storage prototype system of agricultural science and technology achievements videos is constructed.The achievements of this dissertation are listed as follows:(1)The hybrid distributed cloud storage architecture for video files is proposed.Firstly,the storage characteristics and difference of distributed file system and common file system are analyzed.On the basis of this,the cloud storage mode of the mixed distributed file system is put forward,and the architecture of the distributed file system is analyzed.Then the corresponding storage methods are made.It includes large file partition,small file merging based on threshold and dynamic multiple replica backup based on file access frequency,which lays a theoretical foundation for following works.(2)A hybrid distributed cloud storage node state monitoring model is constructed.In this dissertation,it mainly introduces the state information collection module,transmission module and processing module for storage node in the video storage monitoring model of agricultural scientific and technological achievements.The information collected in storage node state includes the CPU usage rate,memory usage rate and disk I/O usage rate.We analyze the heartbeat monitoring method of HDFS and Ceph,and transmit the node state information by optimizing the heartbeat protocol.Then we analyzed the storage node information processing method in the virtual scheduling layer and proposed the algorithm model of the distributed file system storage performance.(3)A retrieval method for video files in cloud storage system is proposed.Firstly,this method identifies the video files and constructs the index files.Based on the HDFS distributed file system built in the hybrid distributed cloud storage architecture which contains the MapReduce parallel computing framework,this dissertation realized the full text retrieval based on the key words of agricultural science and technology achievements.The results show that the average execution time of MapReduce framework retrieval method is 6.75 seconds.(4)A security access strategy for cloud storage of agricultural science and technology achievements is constructed.The characteristics,data isolation,data sharing,resource usage,cost and security of three multi-tenant data isolation architecture are compared and analyzed.Then a four level security strategy based on roles and permission is put forward to set the rights of agricultural scientific and technological achievements videos.So that the corresponding access rights can be obtained by each type of users,which simplifies the complexity of the authorization management.The user identity based multiple security authentication mechanism is proposed,which uses the unique identifier of the user identity as the public key,and the corresponding resources are allocated to the user after authentication.(5)The video cloud storage prototype system for agricultural science and technology achievements is implemented.According to the storage need of agricultural science and technology achievements videos,the application process of the system is discussed.Then,the system function and the data structure are designed.The deployment plan of the system is also introduced.Finally,the practical trials show that the research results are feasibility and practicability. |
