【文章內容簡介】 ?有可能是多個用戶同時進行，使最后寫的用戶生效 ? Append：對文件的添加，直接對遠端文件的操作 , 遠端立刻改變。 ?允許多個用戶同時操作，但并發(fā)寫是隔行進行的 網格計算－ Grid Computing 肖儂 File cache ? “File open” 將遠程文件傳輸到本地 cache ?避免多個本地進程對同一文件的重復打開 ? Cache與用戶相關，允許用戶通過本地資源管理工具對其進行管理 ?程序通過 cache API 訪問文件 cache ? 用戶可以通過 GRAM遠程管理 cache ?一個用戶可擁有多個 cache ，每個 Cache對應一個條目，記錄打開的數目，關閉減少數目，當數目為 0，當該 cache文件將被刪除。 網格計算－ Grid Computing 肖儂 三種安全認證方式 ? 普通的匿名 ftp、 方式，即沒有認證 ? 進程之間進行的 GSI認證 ? 未來還將發(fā)展到基于 SSL認證的 ftp或 訪問 網格計算－ Grid Computing 肖儂 工作流程 globusjobrun Local Machine Remote Machine DUROC GASS Server GRAM Client GSI GRAM Gatekeeper GSI GRAM JobManager GASS Client App Nexus GRAM Client GSI MultiRSL Request Remote Machine GRAM Gatekeeper GSI GRAM JobManager GASS Client App Nexus Single RSL Single RSL Parse 網格計算－ Grid Computing 肖儂 GASS RSL Extensions ? executable, stdin, stdout, stderr can be local files or URLs ? executable and stdin loaded into local cache before job begins (on frontend node) ? stdout, stderr handled via GASS append mode ? Cache cleaned after job pletes 網格計算－ Grid Computing 肖儂 GASS/RSL Example amp。(executable= (stdin= (stdout=/home/bester/output) (stderr= 網格計算－ Grid Computing 肖儂 GASS API ? GLOBUS GASS_CACHE API ? GLOBUS GASS FILE ACCESS API ? GLOBUS GASS SERVER API ? GLOBUS GASS SERVER_EZ API ? GLOBUS GASS CLIENT API 網格計算－ Grid Computing 肖儂 GASS File Access API ? Minimum changes to application ? globus_gass_open(), globus_gass_close() ?Same as open(), close() but use URLs instead of filenames ?Caches URL in case of multiple opens ?Return descriptors to files in local cache or sockets to remote server ? globus_gass_fopen(), globus_gass_fclose() 網格計算－ Grid Computing 肖儂 Remove cache reference Upload changes Modified no yes globus_gass_open()/close() Download File into cache open cached file, add cache reference URL in cache? no yes globus_gass_open() globus_gass_close() 網格計算－ Grid Computing 肖儂 globus_gass_transfer ? Common API for transferring remote files/data over various protocols ? and currently supported ?ftp will be supported in future release ? Supports put and get operations on an URL ? Allows for efficient transfer to/from files or direct to/from memory ? Allows any application to easily add customized file/data service capabilities 網格計算－ Grid Computing 肖儂 globus_gass_copy ? Simple API for copying data from a source to a destination ?URL used for source and destination ?(s), (gsi)ftp, file ?When transferring from ftp to ftp, it uses 3rd party transfer (. client mediated, direct servertoserver transfer) ? globusurlcopy program is simple wrapper around the globus_gass_copy API 網格計算－ Grid Computing 肖儂 globusgassserver ? Simple file server ?Run by user wherever necessary ?Secure protocol, using GSI ?APIs for embedding server into other programs ? Example globusgassserver –r –w t ?r: Allow files to be read from this server ?w: Allow files to be written to this server ?t: Tilde expand (~/… ? $(HOME)/…) ?help: For list