Tiziana FerrariNetwork Metrics Requirements and Usage for WP11 Tiziana Ferrari

Tiziana FerrariNetwork Metrics Requirements and Usage for WP12 Applicability examples Integration of network info into the scheduling policy: –To define the most suitable Storage Element for one or more Computing Elements Triggering of data transfers –To gather in a single Storage Element portions of data sets partioned among several Ses List of applications to be developed further…

Tiziana FerrariNetwork Metrics Requirements and Usage for WP13 Network information CloseSE attribute: –CloseSE = {(closeness 1, SE 1 ), …, (closeness n, SE n )} closeness(CE, SE) = max 0<i<m, 0<j<n {closeness(CE i,SE j )} –Closeness varies in [0,1] –0 = SE unreachable –1 = SE on the same LAN Definitions –r: Round Trip Time, R max : max RTT, –p loss : packet loss frequency; –th: throughput; th max : maximum throughput closeness i, j (p loss,r,th) = 0 if p loss 0 closeness i, j (p loss,r,th) = th / th max r/ rmax where 0 < < 1 otherwise

Tiziana FerrariNetwork Metrics Requirements and Usage for WP14 Closeness function Fig 1: alpha = 2Fig 2: alpha = 10

Tiziana FerrariNetwork Metrics Requirements and Usage for WP15 Triggering of data transfers Initial assumption: all the SEs in a given set SE list = (SE 1, SE 2, …, SE n ) are equally distant from a given CE Definitions: –Inter SE distance: D(SE i ) = 1 j n, j i closeness(SE i, SE j ) – I : data portion stored by each SE i –Optimization function: opt(SE i ) = min j D(SE j ) * i/ max where in [0,1] SE is the selected Storage Element for computing element CE iff: SE = SE i iff opt(SE i ) = min j D(SE j ) * i/ max