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GRID’05 EGEE Summer School Budapest - 1
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Grid Data Management Gabor Hermann on the base of lecture of Simone Campana LCG Experiment Integration and Support CERN IT EGEE is a project funded by the European Union under contract IST
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 3
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 4
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Data Management: general concepts
What does “Data Management” mean? Users and applications produce and require data Data may be stored in Grid files Granularity is at the “file” level (no data “structures”) Users and applications need to handle files on the Grid Files are stored in appropriate permanent resources called “Storage Elements” (SE) Present almost at every site together with computing resources We will treat a storage element as a “black box” where we can store data Appropriate data management utilities/services hide internal structure of SE Appropriate data management utilities/services hide details on transfer protocols GRID’05 EGEE Summer School Budapest - 5
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Data Management: general concepts
A Grid file is READ-ONLY (at least in egee/LCG) It can not be modified It can be deleted (so it can be replaced) Files are heterogeneous (ascii, binary …) High level Data Management tools (lcg_utils, see later) hide transport layer details (protocols …) Storage location To use lower level tools (edg-gridftp, see later ) you need some knowledge of the transport layer some knowledge of Storage Element implementation GRID’05 EGEE Summer School Budapest - 6
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Some details on protocols
Data channel protocol: mostly gridFTP (gsiftp) secure and efficient data movement extends the standard FTP protocol Public-key-based Grid Security Infrastructure (GSI) support Third-party control of data transfer Parallel data transfer Other protocols are available, especially for File I/O rfio protocol: for CASTOR SE (and classic SE) Not yet GSI enabled gsidcap protocol: for secure access to dCache SE file protocol: for local file access Other Control Channel Protocols (SRM, discussed in SE lecture … ) GRID’05 EGEE Summer School Budapest - 7
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Data Management operations
Upload a file to the grid U ser need to store data in SE (from a U I) Application need to store data in SE (from a CE) U ser need to store the application (to be retrieved and run on a CE) For small files the InputSandbox can be used (see WMS lecture) CE SE CE SE Installation tool (Tango) Several Grid Components UI GRID’05 EGEE Summer School Budapest - 8
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Data Management operations
Download files from the grid User need to retrieve (onto the UI) data stored into SE For small files produced in WN the OutputSandbox can be used (see WMS lecture) Applications need to copy data locally (into the CE) and use them The application itself must be downloaded onto the CE and run CE SE CE SE spark … Several Grid Components UI GRID’05 EGEE Summer School Budapest - 9
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Data Management operations
Replicate a file across different SEs Load share balacing of computing resources Often a job needs to run at a site where a copy of input data is present See InputData JDL attribute in WMS lecture Performance improvement in data access Several applications might need to access the same file concurrently Important for redundancy of key files (backup) CE SE CE SE Several Grid Components UI GRID’05 EGEE Summer School Budapest - 10
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One of the base idea of LCG:
Let us bring the little programs close to the big files Asymmetry in JDL: In given situation it is the task of the user to copy the GRID files mentioned in Input Data to the CE The JDL supports the creating of GRID files from local files via Output Data GRID’05 EGEE Summer School Budapest - 11
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Data management operations
Data Management means movement and replication of files across/on grid elements Grid DM tools/applications/services can be used for all kind of files HOWEVER Data Management focuses on “large” files large means greater than ~20MB Tipically on the order of few hundreds MB Tools/applications/services are optimized to deal with large files In many cases, small files can be efficiently treated using different procedures Examples: User can ship data to be used by the application on the WN (and possibly the application itself) using the InputSandbox (see WMS lecture) User can retrieve (on the UI) data generated by a job (on the WN) using the OutputSandbox (see WMS lecture) GRID’05 EGEE Summer School Budapest - 12
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Files & replicas: Name Conventions
Logical File Name (LFN) An alias created by a user to refer to some item of data, e.g. “lfn:cms/ /run2/track1” Globally Unique Identifier (GUID) A non-human-readable unique identifier for an item of data, e.g. “guid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6” Site URL (SURL) (or Physical File Name (PFN) or Site FN) The location of an actual piece of data on a storage system, e.g. “srm://pcrd24.cern.ch/flatfiles/cms/output10_1” (SRM) “sfn://lxshare0209.cern.ch/data/alice/ntuples.dat” (Classic SE) Transport URL (TURL) Temporary locator of a replica + access protocol: understood by a SE, e.g. “rfio://lxshare0209.cern.ch//data/alice/ntuples.dat” Logical File Name 1 Logical File Name n GUID Physical File SURL n Physical File SURL 1 . TURL 1 TURL n GRID’05 EGEE Summer School Budapest - 13
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 14
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Well… we need a FILE CATALOGUE
File Catalogs At this point you should ask: How do I keep track of all my files on the Grid? Even if I remember all the lfns of my files, what about someone else files? Anyway, how does the Grid keep track of associations lfn/GUID/surl? Well… we need a FILE CATALOGUE GRID’05 EGEE Summer School Budapest - 15
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Cataloging Requirements
Need to keep track of the location of copies (replicas) of Grid files Replicas might be described by attributes Support for METADATA Could be “system” metadata or “user” metadata Potentially, milions of files need to be registered and located Requirement for performance Distributed architecture might be desirable scalability prevent single-point of failure Site managers need to change autonomously file locations GRID’05 EGEE Summer School Budapest - 16
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File Catalogs in egee/LCG
Access to the file catalog The DM tools and APIs and the WMS interact with the catalog Hide catalogue implementation details Lower level tools allow direct catalogue access EDG’s Replica Location Service (RLS) Catalogs in use in LCG-2 Replica Metadata Catalog (RMC) + Local Replica Catalog (LRC) Some performance problems detected during LCG Data Challenges New LCG File Catalog (LCF) Already being certified; deployment in January 2005 Coexistence with RLS and migration tools provided Better performance and scalability Provides new features: security, hierarchical namespace, transactions... GRID’05 EGEE Summer School Budapest - 17
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Overview of File catalogues
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File Catalogs: The RLS RMC: LRC: RMC LRC Stores LFN-GUID mappings
Accessible by edg-rmc CLI + API LRC: Stores GUID-SURL mappings Accessible by edg-lrc CLI + API DM LRC RMC Logical File Name 1 Logical File Name 2 Logical File Name n GUID Physical File SURL n Physical File SURL 1 RMC LRC GRID’05 EGEE Summer School Budapest - 19
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File Catalogs: The LFC One single catalog
LFN acts as main key in the database. It has: Symbolic links to it (additional LFNs) Unique Identifier (GUID) System metadata Information on replicas One field of user metadata GUID Xxxxxx-xxxx-xxx-xxx- System Metadata “size” => 10234 “cksum_type” => “MD5” “cksum” => “yy-yy-yy” Symlink /grid/dteam/mydir/mylink Replica srm://host.example.com/foo/bar host.example.com LFN /grid/dteam/dir1/dir2/file1.root User Metadata User Defined Metadata GRID’05 EGEE Summer School Budapest - 20
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File Catalogs: The LFC (II)
Fixes performance and scalability problems seen in EDG Catalogs Cursors for large queries Timeouts and retries from the client Provides more features than the EDG Catalogs User exposed transaction API (+ auto rollback on failure of mutating method call) Hierarchical namespace and namespace operations (for LFNs) /grid/<VO>/….. Integrated GSI Authentication + Authorization Access Control Lists (Unix Permissions and POSIX ACLs) Checksums Interaction with other components Supports Oracle and MySQL database backends Integration with GFAL and lcg_util APIs complete New specific API provided New features will be added (requests welcome!) ROOT Integration in progress POOL Integration will be provided soon VOMS will be integrated GRID’05 EGEE Summer School Budapest - 21
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LFC commands Summary of the LFC Catalog commands lfc-chmod
Change access mode of the LFC file/directory lfc-chown Change owner and group of the LFC file-directory lfc-delcomment Delete the comment associated with the file/directory lfc-getacl Get file/directory access control lists lfc-ln Make a symbolic link to a file/directory lfc-ls List file/directory entries in a directory lfc-mkdir Create a directory lfc-rename Rename a file/directory lfc-rm Remove a file/directory lfc-setacl Set file/directory access control lists lfc-setcomment Add/replace a comment GRID’05 EGEE Summer School Budapest - 22
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LFC C API Low level methods (many POSIX-like): lfc_setacl lfc_setatime
lfc_setcomment lfc_seterrbuf lfc_setfsize lfc_starttrans lfc_stat lfc_symlink lfc_umask lfc_undelete lfc_unlink lfc_utime send2lfc lfc_access lfc_aborttrans lfc_addreplica lfc_apiinit lfc_chclass lfc_chdir lfc_chmod lfc_chown lfc_closedir lfc_creat lfc_delcomment lfc_delete lfc_deleteclass lfc_delreplica lfc_endtrans lfc_enterclass lfc_errmsg lfc_getacl lfc_getcomment lfc_getcwd lfc_getpath lfc_lchown lfc_listclass lfc_listlinks lfc_listreplica lfc_lstat lfc_mkdir lfc_modifyclass lfc_opendir lfc_queryclass lfc_readdir lfc_readlink lfc_rename lfc_rewind lfc_rmdir lfc_selectsrvr GRID’05 EGEE Summer School Budapest - 23
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Important environment variables:
export LCG_GFAL_INFOSYS=grid152.kfki.hu: Must be set for each catalogue type export LCG_CATALOG_TYPE=lfc Must be set only for LFC export LFC_HOST=grid155.kfki.hu Must be set only for LFC GRID’05 EGEE Summer School Budapest - 24
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 25
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Data Management (Replication, Indexing, Querying)
DM CLIs & APIs overview User Tools Data Management (Replication, Indexing, Querying) lcg_utils: CLI + C API edg-rm: CLI + API Cataloging Storage File I/O Data transfer GFAL C API GFAL C API GFAL C API (GFAL C API) Classic SE EDG LFC SRM RFIO DCAP GridFTP bbFTP edg-rmc edg-lrc CLI + API edg- gridtp Globus API CLI+ API SRM API rfio API bbFTP API dcap API GRID’05 EGEE Summer School Budapest - 26
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SRM Storage Management
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Data management tools Replica manager: lcg-* commands + lcg_* API
Provide (all) the functionality needed by the egee/LCG user Combine file transfer and cataloging as an atomic transaction Insure consistent operations on catalogues and storage systems Offers high level layer over technology specific implementations Based on the Grid File Access Library (GFAL) API Discussed in SE section edg-gridftp tools: CLI Complete the lcg_utils with GridFTP operations Lower level layer w.r.t. Replica Manager Only for gridFTP protocol Functionality available in GFAL May be implemented as lcg-* commands GRID’05 EGEE Summer School Budapest - 28
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DM CLIs & APIs: Old EDG tools
Old versions of EDG CLIs and APIs still available File & replica management edg-rm Implemented (mostly) in java Catalog interaction (only for EDG catalogs) edg-lrc edg-rmc Java and C++ APIs Use discouraged Worse performance (slower) New features added only to lcg_utils Less general than GFAL and lcg_utils GRID’05 EGEE Summer School Budapest - 29
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 30
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lcg-utils commands Replica Management File Catalog Interaction lcg-cp
Copies a grid file to a local destination lcg-cr Copies a file to a SE and registers the file in the catalog lcg-del Delete one file lcg-rep Replication between SEs and registration of the replica lcg-gt Gets the TURL for a given SURL and transfer protocol lcg-sd Sets file status to “Done” for a given SURL in a SRM request File Catalog Interaction lcg-aa Add an alias in LFC for a given GUID lcg-ra Remove an alias in LFC for a given GUID lcg-rf Registers in LFC a file placed in a SE lcg-uf Unregisters in LFC a file placed in a SE lcg-la Lists the alias for a given SURL, GUID or LFN lcg-lg Get the GUID for a given LFN or SURL lcg-lr Lists the replicas for a given GUID, SURL or LFN GRID’05 EGEE Summer School Budapest - 32
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Gathering informations: lcg-infosites
lcg-infosites --vo gilda se ************************************************************* These are the related data for gilda: (in terms of SE) Avail Space(Kb) Used Space(Kb) SEs grid3.na.astro.it grid009.ct.infn.it grid003.cecalc.ula.ve testbed005.cnaf.infn.it gilda-se01.pd.infn.it GRID’05 EGEE Summer School Budapest - 33
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lcg_utils CLI : usage example
lcg-rep --vo gilda \ -d grid003.cecalc.ula.ve lfn:simone-important ls -l important-file.txt -rw-r--r scampana users Oct 31 17:09 important-file.txt lcg-lr --vo gilda lfn:simone-important sfn://grid3.na.astro.it/flatfiles/SE00/gilda/generated/ / \ file4c7c2ad6-4d93-4cd2-be24-bf4239f58208 lcg-cr --vo gilda -l lfn:simone-important \ -d grid3.na.astro.it file://`pwd`/important-file.txt guid:08d02e56-bdf a4da-e0247c188242 lcg-lr --vo gilda lfn:simone-important sfn://grid003.cecalc.ula.ve/flatfiles/SE00/gilda/generated/ / \ file39568d15-e873-4f b8862ae77c36 sfn://grid3.na.astro.it/flatfiles/SE00/gilda/generated/ / \ file4c7c2ad6-4d93-4cd2-be24-bf4239f58208 lcg-del --vo gilda -a lfn:simone-important lcg-lr --vo gilda lfn:simone-important lcg_lr: No such file or directory IMPORTANT The lcg_utils (both CLI and API described later) need to access the Information System (BDII). The name of the BDII host used by lcg_utils is specified in the environment variable LCG_GFAL_INFOSYS REMEMBER THAT, ESPECIALLY WHEN PERFORMING DATA MANAGEMENT OPERATIONS FROM THE WN We have a local file in our UI in Catania Upload the file in Naples (Italy) The file is effectively there … Delete all the replicas in the storage elements. …. Let’ s replicate it to Merida now … GRID’05 EGEE Summer School Budapest - 34
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 35
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lcg_utils API lcg_utils API: Single shared library Single header file
High-level data management C API Same functionality as lcg_util command line tools Single shared library liblcg_util.so Single header file lcg_util.h (+ linking against libglobus_gass_copy_gcc32.so) GRID’05 EGEE Summer School Budapest - 36
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lcg_utils: Replica management
int lcg_cp (char *src_file, char *dest_file, char *vo, int nbstreams, char * conf_file, int insecure, int insecure); int lcg_cr (char *src_file, char *dest_file, char *guid, char *lfn, char *vo, char *relative_path, int nbstreams, char *conf_file, int insecure, int verbose, char *actual_guid); int lcg_del (char *file, int aflag, char *se, char *vo, char *conf_file, int insecure, int verbose); int lcg_rep (char *src_file, char *dest_file, char *vo, char *relative_path, int nbstreams, char *conf_file, int insecure, int verbose); int lcg_sd (char *surl, int regid, int fileid, char *token, int oflag); GRID’05 EGEE Summer School Budapest - 37
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lcg_utils: Catalog interaction
int lcg_aa (char *lfn, char *guid, char *vo, char *insecure, int verbose); int lcg_gt (char *surl, char *protocol, char **turl, int *regid, int *fileid, char **token); int lcg_la (char *file, char *vo, char *conf_file, int insecure, char ***lfns); int lcg_lg (char *lfn_or_surl, char *vo, char *conf_file, int insecure, char *guid); int lcg_lr (char *file, char *vo, char *conf_file, int insecure, char ***pfns); int lcg_ra (char *lfn, char *guid, char *vo, char *conf_file, int insecure); int lcg_rf (char *surl, char *guid, char *lfn, char *vo, char *conf_file, int insecure, int verbose, char *actual_guid); int lcg_uf (char *surl, char *guid, char *vo, char *conf_file, int insecure); GRID’05 EGEE Summer School Budapest - 38
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Available APIs #include <iostream> #include <stdlib.h> #include <string.h> #include <string> #include <stdio.h> #include <errno.h> // lcg_util is a C library. Since we write C++ code here, we need to // use extern C // extern "C" { #include <lcg_util.h> } using namespace std; /***************************************************************************************/ /* The folling example code shows you how you can use the lcg_util API for */ /* replica management. We expect that you modify parts of this code in */ /* to make it work in your environment. This is particularly indicated */ /* by ACTION, i.e. your action is required */ /**************************************************************************************/ int main () cout << "Data Management API Example " << endl; char *vo = "cms"; // ACTION: fill in your correct VO here: gilda ! cout << " " << endl; C APIs globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 39
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Available APIs Copy and Register
// Copy a local file to the Storage Element and register it in RLS // char *localFile = "file:/tmp/test-file"; // ACTION: create a testfile char *destSE = "lxb0707.cern.ch"; // ACTION: fill in a specific SE char *actualGuid = (char*) malloc(50); int verbose = 2; // we use verbosity level 2 int nbstreams = 8; // we use 8 parallel streams to transfer a file lcg_cr(localFile, destSE, NULL, NULL, vo, NULL, nbstreams, NULL, 0, verbose, actualGuid); if (errno) { perror("Error in copyAndRegister:"); return -1; } else { cout << "We registered the file with GUID: " << actualGuid << endl; } cout << " " << endl; Copy and Register globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 40
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Available APIs List Replicas
// Call the listReplicas (lcg_lr) method and print the returned URLs // // The actualGuid does not contain the prefix "guid:". We add it here and // then use the new guid as a parameter to list replicas std::string guid = "guid:"; guid.insert(5,actualGuid); char ***pfns = (char***) malloc(200); lcg_lr((char*) guid.c_str(), vo, NULL, 0, pfns); if(errno) { perror("Error in listReplicas:"); free(pfns); return -1; } else { cout << "PFN = " << **pfns << endl; } cout << " " << endl; List Replicas globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 41
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Available APIs Delete Replica
// Delete the replica again // int rc = lcg_del((char*) guid.c_str(), 1, destSE, vo, NULL, 0, verbose); if(rc != 0) { perror("Error in delete:"); return -1; } else { cout << "Delete OK" << endl; } return 0; Delete Replica globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 42
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Available APIs Makefile used
CC = g++ GLOBUS_FLAVOR = gcc32 all: data-management data-management: data-management.o $(CC) -o data-management \ -L${GLOBUS_LOCATION}/lib -lglobus_gass_copy_${GLOBUS_FLAVOR} \ -L${LCG_LOCATION}/lib -llcg_util -lgfal \ data-management.o data-management.o: data-management.cpp $(CC) -I ${LCG_LOCATION}/include -c data-management.cpp clean: rm -rf data-management data-management.o Makefile used globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 43
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 44
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Grid File Access Library
GFAL is a library to provide access to Grid files File I/O, Catalog Interaction, Storage Interaction Abstraction from specific implementations Transparent interaction with the information service, the file catalogs… Single shared library in threaded and unthreaded versions libgfal.so, libgfal_pthr.so Single header file gfal_api.h Cataloging Storage Data transfer Data Management (Replication, Indexing, Querying) EDG LFC SRM Classic SE gridftp RDT File I/O rfio dcap GRID’05 EGEE Summer School Budapest - 45
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GFAL: Catalog API int create_alias (const char *guid, const char *lfn, long long size) int guid_exists (const char *guid) char *guidforpfn (const char *surl) char *guidfromlfn (const char *lfn) char **lfnsforguid (const char *guid) int register_alias (const char *guid, const char *lfn) int register_pfn (const char *guid, const char *surl) int setfilesize (const char *surl, long long size) char *surlfromguid (const char *guid) char **surlsfromguid (const char *guid) int unregister_alias (const char *guid, const char *lfn) int unregister_pfn (const char *guid, const char *surl) GRID’05 EGEE Summer School Budapest - 46
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GFAL: Storage API int deletesurl (const char *surl)
int getfilemd (const char *surl, struct stat64 *statbuf) int set_xfer_done (const char *surl, int reqid, int fileid, char *token, int oflag) int set_xfer_running (const char *surl, int reqid, int fileid, char *token) char *turlfromsurl (const char *surl, char **protocols, int oflag, int *reqid, int *fileid, char **token) int srm_get (int nbfiles, char **surls, int nbprotocols, char **protocols, int *reqid, char **token, struct srm_filestatus **filestatuses) int srm_getstatus (int nbfiles, char **surls, int reqid, char *token, struct srm_filestatus **filestatuses) GRID’05 EGEE Summer School Budapest - 47
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GFAL: File I/O API (I) int gfal_access (const char *path, int amode);
int gfal_chmod (const char *path, mode_t mode); int gfal_close (int fd); int gfal_creat (const char *filename, mode_t mode); off_t gfal_lseek (int fd, off_t offset, int whence); int gfal_open (const char * filename, int flags, mode_t mode); ssize_t gfal_read (int fd, void *buf, size_t size); int gfal_rename (const char *old_name, const char *new_name); ssize_t gfal_setfilchg (int, const void *, size_t); int gfal_stat (const char *filename, struct stat *statbuf); int gfal_unlink (const char *filename); ssize_t gfal_write (int fd, const void *buf, size_t size); GRID’05 EGEE Summer School Budapest - 48
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GFAL protocol of File Open
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GFAL: File I/O API (II) int gfal_closedir (DIR *dirp);
int gfal_mkdir (const char *dirname, mode_t mode); DIR *gfal_opendir (const char *dirname); struct dirent *gfal_readdir (DIR *dirp); int gfal_rmdir (const char *dirname); GRID’05 EGEE Summer School Budapest - 50
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 51
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Advanced utilities: edg-gridftp
Used for low level management of file/directories in SEs edg-gridftp-exists TURL Checks if file/dir exists on a SE edg-gridftp-ls TURL Lists a directory on a SE globus-url-copy srcTURL dstTURL Copies files between SEs edg-gridftp-mkdir TURL Creates a directory on a SE edg-gridftp-rename srcTURL dstTURL Renames a file on a SE edg-gridftp-rm TURL Removes a file from a SE edg-gridftp-rmdir TURL Removes a directory on a SE GRID’05 EGEE Summer School Budapest - 52
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edg-gridftp example Create and delete a directory in a GILDA Storage Element GRID’05 EGEE Summer School Budapest - 53
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Other Advanced CLI&API
globus-url-copy srcTURL destTURL low level file transfer Interaction with RLS components edg-lrc command (actions on LRC) edg-rmc command (actions on RMC) C++ and Java API for all catalog operations Using low level CLI and API is STRONGLY discouraged Risk: loose consistency between SEs and catalogues REMEMBER: a file is in Grid if it is BOTH: stored in a Storage Element registered in the file catalog globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 54
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Overview Introduction on Data Management (DM) File catalogs
General Concepts Some details on transport protocols Data management operations Files & replicas: Name Convention File catalogs Cataloging requirements and catalogs in egee/LCG RLS file catalog LCG file catalog DM tools: overview Data Management CLI lcg_utils Data Management API GFAL Advanced concepts Advanced utilities: CLI&APIs OutputData JDL attribute Conclusions GRID’05 EGEE Summer School Budapest - 56
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Summary We provided a description to the egee/LCG Data Management Middleware Components and Tools We described how to use the available CLIs Use-case scenarios of Data Movement on Grid We presented the available APIs An example usage of lcg_util library is shown globus-url-copy is a low level tool for secure copying. It should only be used if just a copy without registering the file in the RC is desired. Otherwise, higher level tools as we discuss now should be used. GRID’05 EGEE Summer School Budapest - 57
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Bibliography General egee/LCG information EGEE Homepage
EGEE’s NA3: User Training and Induction LCG Homepage LCG-2 User Guide GILDA GENIUS (GILDA web portal) GRID’05 EGEE Summer School Budapest - 58
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Bibliography Information on Data Management middleware
LCG-2 User Guide (chapters 3rd and 6th) Evolution of LCG-2 Data Management. J-P Baud, James Casey. Globus 2.4 GridFTP GFAL GRID’05 EGEE Summer School Budapest - 59
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Bibliography Information on egee/LCG tools and APIs Manpages (in UI)
lcg_utils: lcg-* (commands), lcg_* (C functions) Header files (in $LCG_LOCATION/include) lcg_util.h CVS developement (sources for commands) logsort=date&sortby=file&hideattic=1&cvsroot=lcgware&path= Information on other tools and APIs EDG CLIs and APIs Globus , ...globus_ftp_client/html , ...globus_ftp_control/html GRID’05 EGEE Summer School Budapest - 60
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