[Spread-users] adding server nodes without restarting

[John Lane Schultz]

1) With Spread 4, if two or more daemons have meaningfully different
configuration files, then they will completely ignore each others'
traffic.

A meaningful difference in configuration files is when the daemons
have different information about the Spread_Segment's in the system.
Each daemon must have the exact same Spread_Segment's listed in the
same order (!) with all the same information about daemons, ips and
ports listed in the same order (!) of the servers. Otherwise, the config files can be different for example in comments, or debug
flags turned on at different servers and so on.

People often use the exact same configuration file for all their
daemons.  Often people will have a single configuration file that all daemons
read off a NFS mount.  If that isn't available then you need to push
the configuration file out to the daemons' disks somehow.

2) Yes.  You can change the configuration files of the daemons and
then using spmonitor instruct all of the daemons to reload their
configuration files.  Some daemons may need to commit suicide if their
information has changed (e.g. - removed a daemon from the system or
changed its IP address/port, etc.).  Unaffected daemons will continue
on operating fine.  Depending on the scope of your changes the
surviving daemons may go through a membership change to "cleanse"
themselves of outdated information.

Hope that helps!

Cheers!
John

---
John Lane Schultz
Spread Concepts LLC
Phn: 443 838 2200 
Fax: 301 560 8875

Tuesday, January 8, 2008, 2:02:27 PM, you wrote:

> Spread appears to get the list of participating servers from a 
> configuration file.  Which leads to the questions:

> 1. what happens if different servers have different configs?
> 2. can you modify the config without shutting everything down?

> -Alex-

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