System Name: ffMAIN
Current Version: 2.0
Organization: Fachbereich Informatik (ABVS/Telematik), Johann-Wolfgang-Goethe-Universitaet Frankfurt
Entry status: authoritative
Supported platforms:
Unix; Win32 (untested but likely, since Tcl/Tk is supported)
Supported languages:
Tcl, [incr Tcl], Java; Perl (Alphatest); other
languages are straightforward to support if they
can read from/write to stdin/stdout.
Implemented standards: none; MASIF, for what it is worth, is under preliminary investigation as a proof-of-concept.
Type of migration:
Depends on language support environment; the current language
environments support weak migration only because it is more
important to us to be able to use the language interpreters
unchanged. If a language offers strong migration ffMAIN can
trivially use this.
How many threads or processes are possible per agent? Depends on language support environment: potentially unlimited number of threads per agent in Java; multiple processes (up to OS limit) in Tcl and [incr Tcl].
Local communication mechanisms and format of data:
Basic communication through (potentially MIME-typed) byte
streams in shared server-maintained information space; other
mechanisms such as sockets, RPC or shared memory can be negotiated
between suitably privileged agents.
Global communication mechanisms:
HTTP
How the communication partner can be addressed:
1. Globally-unique URL (not currently between agents)
2. Local identifier
Resource access control mechanism:
1. Unix process resource limits (memory, CPU time, ...)
2. Language support environment can enforce further limits
Agent tracking:
1. Local register of agents on a particular server
2. Agents can be reached through `home server'
Directory of services:
1. Server-local directory with simple local trading facilities
2. More sophisticated directories and traders can be implemented as (stationary) agents
Type of code migration:
Depends on language support environment; Tcl agents are migrated
as a whole but Java agents can download missing classes on demand from the `home server'
Other special features:
Not exclusively Java-based; cross-language agent communication;
fine-grained security mechanism available; WWW integration;
agent server is feature-complete, efficient HTTP server
Availability:
source code
License terms:
Tcl/Tk license (BSD-like)
Article that describe the current system best:
Technical report in preparation; see A. Lingnau, O. Drobnik and
P. Doemel, `An HTTP-based Infrastructure for Mobile Agents',
Fourth Int'l World Wide Web Conference Proceedings (Boston, Dec
1995), World Wide Web Journal 1 (1995), pp. 461-71 for basic
concepts.
Year of first publication of systems description: 1995
Project URL: http://www.tm.informatik.uni-frankfurt.de/Projekte/MA/
Contacts Email Address: lingnau@tm.informatik.uni-frankfurt.de
Last modification date of this entry: Tue Jun 29 18:38:45 MET DST 1999