AliEnFS - a Linux File System for the AliEn Grid Services

Among the services offered by the AliEn (ALICE Environment http://alien.cern.ch) Grid framework there is a virtual file catalogue to allow transparent access to distributed data-sets using various file transfer protocols. $alienfs$ (AliEn File System) integrates the AliEn file catalogue as a new file system type into the Linux kernel using LUFS, a hybrid user space file system framework (Open Source http://lufs.sourceforge.net). LUFS uses a special kernel interface level called VFS (Virtual File System Switch) to communicate via a generalised file system interface to the AliEn file system daemon. The AliEn framework is used for authentication, catalogue browsing, file registration and read/write transfer operations. A C++ API implements the generic file system operations. The goal of AliEnFS is to allow users easy interactive access to a worldwide distributed virtual file system using familiar shell commands (f.e. cp,ls,rm ...) The paper discusses general aspects of Grid File Systems, the AliEn implementation and present and future developments for the AliEn Grid File System.Comment: 9 pages, 12 figure

Survey on security issues in file management in cloud computing environment

Cloud computing has pervaded through every aspect of Information technology in past decade. It has become easier to process plethora of data, generated by various devices in real time, with the advent of cloud networks. The privacy of users data is maintained by data centers around the world and hence it has become feasible to operate on that data from lightweight portable devices. But with ease of processing comes the security aspect of the data. One such security aspect is secure file transfer either internally within cloud or externally from one cloud network to another. File management is central to cloud computing and it is paramount to address the security concerns which arise out of it. This survey paper aims to elucidate the various protocols which can be used for secure file transfer and analyze the ramifications of using each protocol.Comment: 5 pages, 1 tabl

Mission Operations Center (MOC) - Precipitation Processing System (PPS) Interface Software System (MPISS)

MPISS is an automatic file transfer system that implements a combination of standard and mission-unique transfer protocols required by the Global Precipitation Measurement Mission (GPM) Precipitation Processing System (PPS) to control the flow of data between the MOC and the PPS. The primary features of MPISS are file transfers (both with and without PPS specific protocols), logging of file transfer and system events to local files and a standard messaging bus, short term storage of data files to facilitate retransmissions, and generation of file transfer accounting reports. The system includes a graphical user interface (GUI) to control the system, allow manual operations, and to display events in real time. The PPS specific protocols are an enhanced version of those that were developed for the Tropical Rainfall Measuring Mission (TRMM). All file transfers between the MOC and the PPS use the SSH File Transfer Protocol (SFTP). For reports and data files generated within the MOC, no additional protocols are used when transferring files to the PPS. For observatory data files, an additional handshaking protocol of data notices and data receipts is used. MPISS generates and sends to the PPS data notices containing data start and stop times along with a checksum for the file for each observatory data file transmitted. MPISS retrieves the PPS generated data receipts that indicate the success or failure of the PPS to ingest the data file and/or notice. MPISS retransmits the appropriate files as indicated in the receipt when required. MPISS also automatically retrieves files from the PPS. The unique feature of this software is the use of both standard and PPS specific protocols in parallel. The advantage of this capability is that it supports users that require the PPS protocol as well as those that do not require it. The system is highly configurable to accommodate the needs of future users

Admission Control Policies for Internet File Transfer Protocols

Server congestion is a major cause of frustration with the Internet. It is not uncommon for a server with a new release of popular software to be swamped by many times more clients than it can possibly handle. Current Internet file transfer protocols, namely FTP and HTTP, do not have any policy to regulate client admission. In this thesis we are concerned with server admission policies that will improve clients\u27 experience with servers under heavy load. Using a purpose-built network simulator, we compare the prevalent protocols with two new protocols that include policies taken from processor scheduling. By applying more intelligent client admission policies it is hoped that the quality of service on the Internet can be improved

CFT: Co-operative file transfer algorithm for multi network interface sessions

File transfer is one of the important operations on the Internet. Generally files are transferred from one machine to another machine through one interface. File transfer can occur through multiple interface connections also. Protocols such as SCTP, transfers data in multiple data stream within a single connection and LFTP transfers file sourced from multiple servers to a single host. Here, we present the concept of using multiple network interfaces for transferring files from a single server. This would ensure the utilization of combined bandwidth of all the interfaces used, so that the rate of file transfer would increase considerably compared to single bandwidth transfer. In this work, we use two interfaces i.e, IEEE 802.3 (Ethernet) and IEEE 802.11 (WiFi) to accomplish the above task. We use a non pre-emptive context switching framework Twisted where threading is avoided for an effective resource utilization. The required file is downloaded utilizing two interfaces instead of one unlike normal file transfer. We analyze the improvement in performance by observing the time taken to download a file using two different interfaces (Ethernet and WiFi) and comparing that with a single interface download (using either Ethernet or WiFi) in real time scenario. We attempt to deal with the issue of when and how to connect through two interfaces which combines the bandwidths of both these interfaces, aiding in improving the performance of file transfer when compared to file transfer using single interface

COMPARISON OF FILE TRANSFER PROTOCOLS

Za pristup podatkovnim (datotečnim) resursima sustava, na korisničkoj razini upotrebljavaju se za to izgrađene namjenske aplikacije. Takav aplikativni softver može se izvršavati lokalno na računalu korisnika i na udaljenom aplikacijskom poslužitelju. U oba slučaja komunikacija korisnika s podatkovnim (datotečnim) poslužiteljem odvija se korištenjem mrežnih resursa. Mrežni resursi predstavljaju najsporije komponente u radu sustava. Aplikativni softver za komunikaciju s datotečnim poslužiteljem može koristiti različite mrežne protokole. U ovom radu analizirani su protokoli za prijenos datoteka na aplikacijskom sloju. Objašnjeni su korišteni sigurnosni mehanizmi u analiziranim protokolima. Izvršeno je mjerenje vremena i brzine prijenosa datoteka u LAN mreži na brzinama 10 Mbps, 100 Mbps i 1 Gbps, te u nezaštićenoj i zaštićenoj (VPN) WAN mreži. Pokazano je da su protokoli koji koriste sigurnosne mehanizme sporiji od protokola koji ne koriste sigurnosne mehanizme. Također je pokazano da korištenje FTP HTTPS sigurnog protokola predstavlja optimalno rješenje – visoka razina sigurnosti i ne značajno manja brzina.To access the system data (file) resources, specially built software is used at the user level. This software can be run locally on the user computer and remotely on the remote application server. In both cases, communication with the database server (file server) takes place using network resources. Network resources are the slowest component in the system. Software that communicates with the file server can use different network protocols. This paper analyzes different file transfer protocols at the application layer of the OSI model. Security mechanisms used in the analyzed protocols are explained. Timing and speed of transferring files in the LAN at the speeds of 10Mbps, 100Mbps and 1Gbps, and the unprotected and protected (VPN), WAN network were measured and noted. It is shown that the protocols that use security mechanisms are slower than those that do not use security mechanisms. It is also shown that the use of FTP HTTPS secure protocol is an optimal solution - high level of security and non-significantly lower speed

The Aerospace Energy Systems Laboratory: A BITBUS networking application

The NASA Ames-Dryden Flight Research Facility developed a computerized aircraft battery servicing facility called the Aerospace Energy Systems Laboratory (AESL). This system employs distributed processing with communications provided by a 2.4-megabit BITBUS local area network. Customized handlers provide real time status, remote command, and file transfer protocols between a central system running the iRMX-II operating system and ten slave stations running the iRMX-I operating system. The hardware configuration and software components required to implement this BITBUS application are required

Reliable transfer of data from ground to space

This paper describes the problems involved in uplink of data from control centers on the ground to spacecraft, and explores the solutions to those problems, past. present. and future. The evolution of this process, from simple commanding to transfer of large volumes of data and commands is traced. The need for reliable end-to-end protocols for commanding and file transfer is demonstrated, and the shortcomings of both existing telecommand protocols and commercial products to meet this need are discussed. Recent developments in commercial protocols that may be adaptable to the mentioned operations environment are surveyed, and current efforts to develop a suite of protocols for reliable transfer in this environment are presented