Introduction

This wiki page presents some results on bulk lfc methods to get replicas against an LFC which support encryption.

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

Encryption is off

Execution time is given in second.

Type of test \ #replicas to get	Test 1	Test 2	Test 3
1	0.29	0.24	0.27
10	0.68	0.26	0.31
100	4.52	0.34	0.59
500	21.66	0.87	1.85
1000	43.14	1.49	3.64
5000	214.6	6.7	16.12
10000	428.64	13.32	31.9

Encryption is on

Execution time is given in second.

Type of test \ #replicas to get	Test 1	Test 2	Test 3
1	0.29	0.24	0.29
10	0.7	0.26	0.32
100	4.58	0.37	0.600
500	21.9	0.89	1.89
1000	43.56	1.54	3.65
5000	216.8	6.91	16.36
10000	433.4	13.54	32.4

The impact of encryption is almost negligeable. -- LanaAbadie - 06 Feb 2008