[Spread-users] Spread shutdown

Yair Amir yairamir at cnds.jhu.edu
Fri Aug 17 14:46:42 EDT 2001


This tool does not exist off hand. If you need one, looking at the source
of monitor.c can show you how to do that with relative ease.

HOWEVER - we are looking into changing the protocol between spread and the monitor.
Currently the monitor is communicating with the spread daemon using unreliable 
udp. This causes omissions especially when you want to check a high speed spread
network from a remote location. We have developed a new monitoring language
and a new monitor (and daemon support) that uses TCP/IP connection which
is reliable. The language is a big step forward since what is there right now
in Spread is far from being general.

Unfortunately, this was not migrated to the public version yet and it is not
a 5 minutes job to do that.

Why is this awkwardness: For a while we thought we will discard the code of Spread 3.x.
We were working on what we then called "Spread 4" which, research-wise, focused on very scalable
wide-area network support (supporting up to 100 sites each of which several tens of computers).
We thought that when "Spread 4" is ready we will just call it another version and dispose
Spread 3.x. However, when "Spread 4" was complete enough, we realized that its performance
for local area settings cannot compete with Spread 3.x even theoretically.

So we changed our strategy. We are not discarding Spread 3.x and what used to be called
Spread 4, is actually our scalable wide-area enhancements to Spread. The monitor project
(By Claudiu Danilov) was done with the previous point of view and is not there for Spread 3.x
Most other stuff that is not connected with the scalable wide-area support migrated over
time into the public version as far as I recall right now.


	:) Yair.	http://www.cnds.jhu.edu	

Daniel Rall wrote:
> Is there commandline control of the operation of Spread (3.16.0)
> (i.e. the only way I know to shutdown is option 8 on the spmonitor
> menu)?  I'm looking for something like apachectl, where I can just say
> `apachectl graceful` or `apachectl stop` from the commandline to get
> what I want.
> dlr at daedalus:dlr$ apachectl --help
> apachectl (start|stop|restart|fullstatus|status|graceful|configtest|help)
> start      - start httpd
> stop       - stop httpd
> restart    - restart httpd if running by sending a SIGHUP or start if
>              not running
> fullstatus - dump a full status screen; requires lynx and mod_status enabled
> status     - dump a short status screen; requires lynx and mod_status enabled
> graceful   - do a graceful restart by sending a SIGWINCH or start if not runningconfigtest - do a configuration syntax test
> help       - this screen
> Also, if no such tool exists, I may end up authoring a preliminary
> version of such.  If it comes to that, is the above format reasonable,
> and should the tool be packaged as part of the spread binary or as a
> separate tool (i.e. spreadctl)?  This would make scripting Spread
> operation much easier.
>                              Daniel Rall

More information about the Spread-users mailing list