Transfer Protocols. A. Requesting Transfer Procedures
Transfer Protocols. In addition to the federation layers which provide the glue to bind together community repositories and data centres, the protocol by which users’ and systems access files in a federated archive must also be considered since this provides the linkages between users and sites. Data can be moved within a federation by a number of methods such as using rsync or scp as low level protocols, wget or curl using an http server, FTP using an ftp server or gridFTP as a secure service. Some federation technologies even come with their own protocols such as iRODS iput, iget and irsync commands. In order to understand what needs to be tested in scalability terms, it is first necessary to understand the use cases for data transfer. Work Package 4 has already identified three relevant service cases; the ‘data replication’, ‘data staging’ and ‘simple storage’ service cases. Of these, the data staging probably represents initially the most challenging in terms of scalability since it has potentially the most stringent performance constraints. The Simple Store, while not having performance constraints, could in the long term present scalability issues with the number of data objects being stored, however this is somewhat less challenging then the Data Staging which impacts the efficiency of analysis work. In addition, as mentioned previously, it is possible that some analysis work will be performed accessing information directly from a data centre, without downloading it to the analysis nodes. Some federation technologies, such as xroot, directly support this by providing POSIX or POSIX-like calls. Others, such as iRODS can be made to support this with some development effort but it is not available ‘out-of-the-box’. For analysis work coded to support this method of access, the stability of the protocol is paramount, as well as the number of concurrent connections that can be supported by the archive and the number that can be performed on a single file (for example, calibration data may be accessed by many jobs concurrently). In the testing we have performed we have tried to assess the performance of storage systems from both these perspectives, streaming and random file access. We have attempted to use protocols which are close to the technology, for instance using iput when using iRODS, or cp for mounted file system baseline testing. Ideally we would also like to test further technologies as time allows such as gridFTP , Unicore UFTP or but that is not part of the initia...
Transfer Protocols. Customer understands that there may be certain transfer protocols such as FTP (File Transfer Protocol) and HTTP (Hyper Text Transfer Protocol) that may allow other service users and Internet users to gain access to Customer’s network. If Customer chooses to run such transfer protocols, then Customer acknowledges and agrees that it does so at Customer’s own risk.
Transfer Protocols. Servicer will work with Position Holder Trust to implement reliable and secure transport methods that best satisfy Position Holder Trust’s requirements. Once established, Servicer agrees that it shall not implement a less secure method without the prior written consent of Position Holder Trust.
