Safe tuplespace-based coordination in multiagent systems

Abstract

Linda is a high level coordination model which allows agents to interact via shared tuplespaces without knowing each other's identities and without having to arrange for a definite rendezvous. This high level of abstraction would make Linda particularly suitable for use as a coordination model for heterogeneous distributed systems, if it were not for the fact that the Linda communication is unsafe.In order to enhance the safety of tuplespaces, this paper introduces a mechanism for establishing security policies that regulate agent access to tuplespaces. Our mechanism is based on a previously published concept of law-governed interaction. It makes a strict separation between the formal statement of a policy, which we call a "law," and the enforcement of this law, which is carried our by a set of policy-independent trusted controllers. A new policy under this scheme is created basically by formulating its law, and can be easily deployed throughout a distributed system. Two examples policies are discussed here in detail: one ensures a secure bidding policy; the other prevents denial of service, by regulating the flow of requests sent to the tuplespaces.

Building autonomic components: The SelfLets approach

“…Moreover, to allow for it to be partially or totally shared among many SelfLets, it relies on LIME [17] middleware. This middleware, which implements a distributed tuple space [16], is used to build and maintain such a "shared memory". The tuple space paradigm provides a high level communication model which allows SelfLets to communicate and coordinate via the shared memory without knowing each other's identity and without having to arrange for a definite rendezvous.…”

Scoped Synchronization Constraints for Large Scale Actor Systems

“…This raises robustness concerns in the presence of faulty agents because any agent may remove any tuple from the space. Several mixed static-dynamic [16,23] and dynamic solutions [13] mitigate the problem by limiting the access to tuples. (See these articles for references to many more approaches.…”

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