globus數(shù)據(jù)管理服務(wù)-閱讀頁
2024-11-01 15:50本頁面
【正文】 ce ?Use LDAP as catalog format and protocol, for consistency ?Use as a building block for other tools ? Advantage ?These services can be used in a wide variety of situations 網(wǎng)格計算－ Grid Computing 肖儂 Replica Manager Components ? Replica catalog definition ?LDAP object classes for representing logicaltophysical mappings in an LDAP catalog ? Lowlevel replica catalog API ?globus_replica_catalog library ?Manipulates replica catalog: add, delete, etc. ? Highlevel reliable replication API ?globus_replica_manager library ?Combines calls to file transfer operations and calls to lowlevel API functions: create, destroy, etc. 網(wǎng)格計算－ Grid Computing 肖儂 Replica Catalog Structure: A Climate Modeling Example Logical File Parent Logical File Jan 1998 Logical Collection C02 measurements 1998 Replica Catalog Location Location Logical File Feb 1998 Size: 1468762 Filename: Jan 1998 Filename: Feb 1998 … Filename: Mar 1998 Filename: Jun 1998 Filename: Oct 1998 Protocol: gsiftp UrlConstructor: nfs/v6/climate Filename: Jan 1998 … Filename: Dec 1998 Protocol: ftp UrlConstructor: pub/pcmdi Logical Collection C02 measurements 1999 網(wǎng)格計算－ Grid Computing 肖儂 Replica Catalog Services as Building Blocks: Examples ? Combine with information service to build replica selection services ?. “find best replica” using performance info from NWS and MDS ?Use of LDAP as mon protocol for info and replica services makes this easier ? Combine with application managers to build data distribution services ?., build new replicas in response to frequent accesses 網(wǎng)格計算－ Grid Computing 肖儂 Relationship to Metadata Catalogs ? Metadata services describe data contents ?Have defined a simple set of object classes ? Must support a variety of metadata catalogs ?MCAT being one important example ?Others include LDAP catalogs, HDF ? Community metadata catalogs ?Agree on set of attributes ?Produce names needed by replica catalog: ?Logical collection name ?Logical file name 網(wǎng)格計算－ Grid Computing 肖儂 replica catalog的具體實現(xiàn) ? 目前是用 Lightweight Directory Access Protocol (LDAP)目錄實現(xiàn)的 ? 以后可能用數(shù)據(jù)庫實現(xiàn) 網(wǎng)格計算－ Grid Computing 肖儂 Replica Catalog Directions ? Many data grid applications do not require tight consistency semantics ?At any given time, you may not be able to discover all copies ?When a new copy is made, it may not be immediately recognized as available ? Allows for much more scalable design ?Distributed catalogs: local catalogs which maintain their own LFN PFN mapping ?Softstate updates as basis for building various configurations of global catalogs 網(wǎng)格計算－ Grid Computing 肖儂 Data Transfer APIs ? The globus_ftp_control API provides access to lowlevel GridFTP control and data channel operations. ? The globus_ftp_client API provides typical GridFTP client operations. ? The globus_gass_copy API provides the ability to start and manage multiple data transfers using GridFTP, HTTP, local file, and memory operations. ?The globusurlcopy program is a thin wrapper around this API 網(wǎng)格計算－ Grid Computing 肖儂 Replica Management APIs ? The globus_replica_catalog API provides basic Replica Catalog operations. ? The globus_replica_management API (under development) bines GridFTP and the Replica Catalog to manage replicated datasets.
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號-1