Introduction

This wiki page presents some results on bulk lfc methods to get replicas.

Bulk methods which have been tested

There are two methods.
  • Test 2: int lfc_getreplicas (int nbguids, const char **guids, const char *se, int *nbentries, struct Cns_filereplicas **rep_entries)
: allows getting the list of LFNs and replicas (sfn) associated with the given list of guids. The output can be filtered with se, which will select only the replicas stored in the given se.
  • Test 3: int lfc_getreplicasl (int nbfiles, const char **paths, const char *se, int *nbentries, struct Cns_filereplicas **rep_entries)
: allows getting the list of guids and replicas (sfn) associated with the given list of LFNs. The output can be filtered with se, which will select only the replicas stored in the given se.

Local LFC server and client

Hw and nw properties

  • LFC server :lxb0981.cern.ch with MySQL (SL4)
  • LFC client : lxb0728.cern.ch (SL3)
  • ping time 0.34ms
  • nb of entries in the DB : 1349134

Test conditions

Tests on different ways to get the replicas stored in the LFC. Each test has been repeated three times (same number of entries in the DB).
  • Test 1 : lfc_getreplica inside a session (we get the information on a replica one by one).
  • Test 2 : lfc_getreplicas.
  • Test 3 : lfc_getreplicasl.

Test results

Execution time is given in second.
Type of test \ #replicas to get Test 1 Test 2 Test 3
1 0.335 0.311 0.350
10 0.697 0.325 0.392
100 4.291 0.434 0.700
500 20.307 0.960 1.902
1000 44.632 1.571 3.809
5000 204.054 7.037 15.864
10000 413.188 13.572 31.448

Execution time of the different type of test in a graph.



This table gives the execution time to get information about one LFN/one guid + one replica. Execution time is given in second.

Type of test \ #replicas to get Test 1 Test 2 Test 3
1 0.335 0.311 0.353
10 0.070 0.0325 0.039
100 0.043 0.004 0.007
500 0.041 0.002 0.004
1000 0.045 0.002 0.004
5000 0.041 0.001 0.003
10000 0.041 0.001 0.003


Local LFC server and remote LFC client

Hw and nw properties

  • LFC server :lxb0981.cern.ch with MySQL (SL4)
  • LFC client (Tawain) : lcg00122.grid.sinica.edu (SL3)
  • ping time : 312.64 ms
  • nb of entries in the DB : 1349134

Test conditions

Tests on different ways to get the list of replicas in the LFC. Each test has been repeated three times (same number of entries in the DB).
  • Test 1 : lfc_getreplica inside a session (we get the information on a replica one by one).
  • Test 2 : lfc_getreplicas.
  • Test 3 : lfc_getreplicasl.

Test results

Execution time is given in second.
Type of test \ #replicas to get Test 1 Test 2 Test 3
1 4.039 3.055 3.087
10 1.008 3.073 3.114
100 71.212 3.753 3.812
500 336.224 4.689 5.176
1000 676.567 5.901 7.914
5000 3358.448 12.097 20.628
10000 6687.534 20.957 37.634

Execution time of the different type of test in a graph.

Execution time is given in second.

Type of test \ #replicas to get Test 1 Test 2 Test 3
1 4.039 3.055 3.087
10 0.101 0.307 0.311
100 0.712 0.037 0.038
500 0.672 0.009 0.010
1000 0.677 0.006 0.008
5000 0.672 0.002 0.004
10000 0.669 0.002 0.004

-- LanaAbadie - 17 Dec 2007

  • Performance LFC Graphic:
    lfc.png
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg lfc_get_1.JPG r1 manage 24.8 K 2007-12-17 - 10:10 LanaAbadie  
JPEGjpg lfc_get_2.JPG r1 manage 21.9 K 2007-12-17 - 10:11 LanaAbadie  
JPEGjpg lfc_get_3.JPG r1 manage 19.9 K 2007-12-17 - 10:11 LanaAbadie  
JPEGjpg lfc_get_4.JPG r1 manage 23.1 K 2007-12-17 - 10:33 LanaAbadie  
JPEGjpg lfc_get_5.JPG r1 manage 22.6 K 2007-12-17 - 10:33 LanaAbadie  
JPEGjpg lfc_get_6.JPG r1 manage 24.3 K 2007-12-17 - 10:33 LanaAbadie  
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Topic revision: r4 - 2008-02-06 - LanaAbadie
 
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