Syncing one source to multple targets in lsyncd 2.0 about lsyncd HOT 11 CLOSED

Multiple targets as a special case are no longer needed. Lsyncd 2 now handles 
multiple Syncs. Sources of syncs may be identical, or one even a subdir of 
another.

lsyncd -rsync /path/to/src host1::module -rsync /path/to/src host2::module

Don't worry about additional inotify ressources. It will only create one 
inotify watch per directory regardless in how many syncs the directory appears. 

It was splited so the targets do not interfer which each other. If host1 goes 
down, host2 will be synced regardless. Or a slow target does not slow down 
other targets.

thank you for that! Now a semi-related question. What is best practice in your 
opinion when wanting to sync both directions? In other words does lsyncd watch 
both source and target if the target is local? Or do I need to create a second 
watch in the opposite direction i.e. lsyncd -rsync [source] [target] -rsync 
[target] [source] and have them both running at the same time? This is in 
regards to failover. Thanks

If you do vice versa you need two syncs. But change the rsync options then! You 
need it to put the partial files in another place and better also only update 
when newer. This cannot be done in command line but requires a config file. 
Currently 2.0.0 rsyncOps can only be one String, so you cannot specify those, 
the best thing to do is to copy the "default_rsync" config out from lsyncd.lua 
paste it in your file and change the rsync options to something better fitting 
the two-way-sync case.

Current SVN and 2.0.1 will allow you to add several options as rsyncOps.

Should the lua for syncing to multiple hosts look like:

sync{
        default.rsync,
        source="/var/www/wiki/",
        target="server1:/var/www/wiki/"
}

sync{
        default.rsync,
        source="/var/www/wiki/",
        target="server2:/var/www/wiki/"       
}


OR can two targets be specified in one sync? (NOTE: Specifying two targets in 
one sync does not result in any complaints from lsyncd)

sync{
        default.rsync,
        source="/var/www/wiki/",
        target="server1:/var/www/wiki/",
        target="server2:/var/www/wiki/"       
}

Regards,

Randy

The former, Lsyncd doesnt see the second as conflict due to Lua syntax this 
actually being an array, the second definition overrides the first.

You can also do fancy stuff like following, since the config file is actually 
just a Lua script being interpreted:

targetlist = {
 "server1:/var/www/wiki/", 
 "server2:/var/www/wiki/"
}

for _, server in ipairs(targetlist) do
  sync{ default.rsync,
    source="/var/www/wiki/",
    target=server
  }
end

Kind regards, Axel

Axel,
i upgraded lsyncd from 2.0.7 to 2.1.5 and trick

for _, server in ipairs(targetlist) do
  sync{ default.rsync,
    source="/var/www/wiki/",
    target=server
  }
end

doesn't work any more:

Error: error preparing /home/user/lsyncd.lua: Parameter "target" unknown. (if 
this is not a typo add it to checkgauge)

How can one sync multiple targets in lsyncd 2.1?

Thanks!

Works for me, can you send me your complete config file?

OK, problem was in using default.rsyncssh instead of default.rsync.

This thread was very helpful for my exact situation, but I'm trying to add one 
more bit of complexity.  I'm attempting to launch a bash script that returns a 
list of valid hosts to sync to and put that into an array. I'm a lua newbie and 
would appreciate any help.  Here's the config:

hostlist=`/home/lsync/hostlist.sh`

hostarray = {}
for host in hostlist:gmatch("%w+") do table.insert(hostarray, host) end
for _, server in ipairs(hostarray) do
  sync {
        default.rsyncssh,
        source = "/test/",
        host = server,
        targetdir = "/test/",
}
end

can i use the below one ?
if no then how can i use this if I want to sync it through rsync module ?
sync {
    default.rsync,
    source="server::module/",
    target="/var/www/",
}