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Bologna Feb 18,2003 DataTAG WP4 meeting2
OUTLINE
Activity summary – Aug ’02->now
Main encountered problems and their solutions
Future evolutions
Bologna Feb 18,2003 DataTAG WP4 meeting3
From the beginning to the current status
Aug ’02– first Glue schema LDAP implementation for the CE
and draft implementation for the SE Sep ’02
– S.Monforte has started RB porting (version 1.2.12, 1 week)
Oct-Nov ’02– S.Andreozzi, V.Ciaschini, E.Ronchieri finalized a
working version for the SC2002 demo Gen ’02
– S.Andreozzi, V.Ciaschini, E.Ronchieri ported the RB, vers. 1.2.21_2
Bologna Feb 18,2003 DataTAG WP4 meeting4
Problems and solutions:services and systems separation
Glue Schema: separation between service and systems implementing them– > different information types before were in
the same entry (CE), now are split in two entries (CE, Subcluster)
CE1 CE2 ClusterCE1 CE2Sub
Cluster
Voname
Voname
Bologna Feb 18,2003 DataTAG WP4 meeting5
Problems and solutions:services and systems separation
For each CE– first query for the service– Second query for the system– Merge of results– classAd transformation
This does not sensitive affect performances It can be possible to improve it
– Possible strategies: query one time the subcluster for all CE’s use of ‘entry keys’ (fictious) to get both CE and subcluster
data at once
Bologna Feb 18,2003 DataTAG WP4 meeting6
Problems and solutions:matchmaking when local SE
Problem:– Data Access Protocols are published in the SE– Required DAP for a job are specified in the JDL– IF at least one required DAP matches one SE DAP,
THEN OK DOES THIS ALWAYS WORK?
– NO E.g.
– For the SE edt001 file, gridftp and rfio are advertised– The user specifies file as DAP– The broker might match this SE with a CE that does not
have local access to the SE
Bologna Feb 18,2003 DataTAG WP4 meeting7
Problems and solutions:matchmaking when local SE
Glue Broker strategy:– Data Access Protocols are published in the SE– Required DAP for a job are specified in the JDL– IF (at least one required DAP matches one SE
DAP) AND NOT (only DAP file matches on a SE not locally accessible by the CE), THEN OK
Bologna Feb 18,2003 DataTAG WP4 meeting8
Problems and solutions:matchmaking when local SE
Ideal strategy:– Each system advertises its Data Access Protocols (a
system can provide Computing or Storage Services)– Each Computing/Storage Service advertises enabled
DAP’s– Required DAP for a job are specified in the JDL– IF (at least there is one common required DAP among
enabled by an SE, enabled by a CE and required in the JDL, THEN OK
This is the most general!!!
Bologna Feb 18,2003 DataTAG WP4 meeting9
Future evolutions
With Glue Schema 1.x, for each service the related Information Service URL will be published– Use this info to free the broker from the constraint
of ALL GRIS’s on the same port Enable the possibility of specify a minimum
amount of disk space for the SE RLS testing OTHER IDEAS???
