ns2 project in goa

ns2 project in goa


ns2 project in goa recall that the match effort for base rules is distributed by

heuristically choosing a restriction attribute (RA) for

each rule. A restriction predicate on the RA restricts

the match effort per rule at each base rule processing

site, thereby distributing the work done in base rule

matching. To achieve this, the metarules are analyzed

at compile time to determine the restrictions on base

rules as follows. Base rule RAs are  ns2 project in goa chosen so that at each site, only

those instances are generated that are relevant to

each other with respect to the set of metarules. However, ns2 project in goa at the same time, we must ensure that

all possible instances are generated over all the

sites. The abovens2 project in goa  two goals may be difficult to satisfy

simultaneously. Generating relevant instances according

to the metarules may require ns2 project in goa generating more instances than in the ordinary case where we

use restriction predicates that divide the range of

each base rule RA according to the processing potential

of the sites, to get match time reductions

per rule and uniform completion times over all

sites. This is so, since the distribution of relevant

instances may not agree ns2 project in goa with that determined by

the algorithm that is only concerned with dividing

up the match effort over all sites. The PARADISER system is now operational with

base rule processing being fully distributed and

metarule processing being carried out at a single MRP.

Initial experiments have shown that for large data

sets, the BRPs perform well under dynamic load balancing

to compute base rule matches in parallel and reduces the match time thus allowing the system to

scale. However, the single site ns2 project in goa MRP emerges as a bot,-

We have begun work on distributing the metarule

processing as well. ns2 project in goa Our current effort is to provide

distributed metarule processing using the full distribution

(FDM) scheme. Our initial experiments point

to typical patterns in the behavior of a rule-based system

as execution progresses. One such pattern is that

after several cycles, only a few metarules are typically

active, since many of the base rules relevant to the

bulk of the metarules do not produce instances after

the first few cycles. Under the FDM scheme, each

metarule is assigned to a distinct processor. Thus, in

a realistic situation, many of the ns2 project in goa MRPs may be inactive.

We have developed protocols that detect whether

or not a particular MRP will be active at a given cycle.

It is then possible to distribute the processing

load of the active MRPs over all available MRPs, i.e.,

we use the resources of the ns2 project in goa inactive MRPs whenever

possible. The load distribution is based on the assumption

that at each cycle, the entire conflict set is available at every MRP, since they can all collect all

of the instances as they are broadc.ast by the BRPs.

Load distribution then reduces to following a protocol

that determines how active ns2 project in goa MRPs will claim the

resources of inactive ones, and then executing some

variant of a popular parallel join algorithm adapted

to our particular needs. In future work, we plan to conduct comparative

studies of the various approaches to distributed control

as detailed in this paper with actual implementations within the PARADISER architecture. We also

intend to explore alternative and useful control specifications of practical importance. In [9], a number

of PARULEL programs are studied and some prelirninary

ideas are presented on how ns2 project in goa to improve the expressivity

of the metarule construct of PARULEL. These

are important open problems that will be the focus of

future work.