This is a short FAQ for D'Agents 2.1.
D'Agents fixes most of the bugs that were found in D'Agents 2.0, provides support for Scheme agents, and includes an optional, high-performance multi-threaded agent server.
The public release of D'Agents 2.1 supports Tcl and Scheme agents. Support for Java agents is available by request.
Our internal version of D'Agents does support Python agents, but it has become apparent that we do not have sufficient development time to bring the Python module to a point where it is suitable for public release. If someone is interested in continuing the development of the Python module, they should contact Bob Gray.
No longer available.
D'Agents is no longer supported.
Check our known bugs web page periodically
Our agent team at Dartmouth has spent most of its time on several projects that examined the use of mobile agents in particular applications. We used D'Agents extensively, but continued development on the core system only slowly.
Check our known bugs web page periodically
There are several possibilities:
1. Make sure that the agentd.conf file includes the linesAllowedMachine localhostand
TrustedMachine localhost
2. Make sure that localhost maps to the special IP address 127.0.0.1, not to the machine's actual IP address. You can check this by typing the command
ping localhostand seeing what IP address is listed in the output. If localhost is not mapped correctly, you may need your system administrator's help to fix it.
3. Make sure that the server's Unix domain socket is on the local filessytem (i.e., make sure that the DATA_DIRECTORY specified in the Makefile is a directory on the local filesystem). If the socket is not on the local filesystem, you must change DATA_DIRECTORY in the Makefile, recompile and reinstall. (The system is much faster with the socket on the local filesystem anyway.)
Agents in D'Agents 2.1 are given a default lifetime by the StartWall and AnonStartWall fields in agentd.conf. You must set these lifetime values large enough to take into account the clock drift of your machines. (We will be fixing this requirement in later releases.) For example, if the clocks on your machines are up to 10 minutes out of sync with each other, you should set the lifetime values to 20 minutes (2 times the clock drift) plus the desired default agent lifetime. Authorized agents that want a longer lifetime can use the require command to get it.
This error message means exactly what it says. The security routines in D'Agents 2.1 require that you redirect standard input (so that it comes from either a Tcl string or a file) when you exec a Unix command. For example, instead of writing
exec whoyou instead must write
exec who << {}
(The Unix who command takes no input so we just redirect standard
input to an
empty Tcl string.) To see an example of a correct exec command, refer
to the who.jump.tcl agent that came with D'Agents, NOT to the who
agent that is discussed in the old documentation for D'Agents 1.1.
The most likely problem is that you are trying one of the examples from the D'Agents 1.1 documentation without making the few changes that are necessary under D'Agents 2.0. Instead of typing in the example agents that are in the old documentation, use the updated example agents that came with D'Agents 2.0. (These updated agents were installed into the examples subdirectory during the installation process. Refer to your Makefile to get the full directory name.)
We will not do any further development on the core D'Agents system, but instead are focusing on wireless-networking and information-retrieval applications in which D'Agents can be used.
We hope to make a release at the end of every quarter (March, June, September and December). We have not done well at maintaining this schedule so far, however, so the safe answer is that we do not know when we will make the next release. The exact contents of each release will depend on our current research focus, current set of students, etc.
There will be no more releases.
The D'Agents Project ended in approximately 2003. The software, and this web site, is no longer maintained. For questions please contact David Kotz.