Hey, Sorry I found this after post here and out of internet to update here.
Thanks On Fri, Mar 10, 2017 at 1:45 PM, R.I.Pienaar <[email protected]> wrote: > hello, > > First read this from 2012 > https://www.devco.net/archives/2012/06/19/mcollective-direct-addressing- > mode.php > > if you're just doing 'mco rpc rpcutil ping -W country=uk' for example > and with default configuration : > > 1* it does a broadcast discovery > 2* if it discovered less than a threshold nodes, it does direct > 3* else if more then threshold it does broadcast. > > In broadcast mode - no guarantee that only discovered nodes get the > request or that discovered nodes get the request. > > Where 'direct' means, send a message to the node via the queue. It > knows which nodes based on a previous broadcast discovery. > > If you use --nodes, or -I without regular expressions, you're telling it > the nodes and other filters shouldn't really matter > > In my case this is a impossible ask: > > % mco rpc rpcutil ping -I dev1.devco.net -W country=uk > .... > Finished processing 1 / 1 hosts in 141.07 ms > > Because dev1 is not in the UK - but -I and --nodes and other plugins are > telling mcollective you've already resolved the discovery stuff and you > know what nodes you want to communicate with so it does so only on the > identities ignoring other filters. Actually the decision is up to the > discovery plugin, and the plugin that drives --nodes and -I just ignores > other filters since you're telling it all it needs to know or care > about. > > At any significant scale and whenever you want to have a reliable known > quantity of nodes (see my blog post), you need to not use broadcast > discovery at all. Broadcast discovery and the broadcast communication > mode is like UDP in networking. Just like with UDP you can build > reliability but you have to bring that with your own > consolidation/auditing, if you're not intending to build that you need > to look towards direct mode to achieve reliability. > > If you want a known quantity of replies and audit those replies and know > they worked and you need to know what nodes should be there, you need to > use some discovery plugin (like your nodes.txt files). Direct is > mcollectives TCP vs the UDP of broadcast. > > Direct mode puts more pressure on your middleware, past a point you > either need to build smaller subcollectives, use smaller node selections > or if you make a giant one use batches. > > So understanding that there are 2 means of communicating with the same > agents you need to consider your needs carefully and when to choose > reliability - and the extra overhead - over unreliability thats more > performant. > > On Fri, Mar 10, 2017, at 03:30, [email protected] wrote: > > Hi, > > > > I just want to understand about direct addressing mode vs broadcast mode. > > I > > believe when we use direct addressing mode whatever mco query we are > > running it will not do broadcast instead it will reach the particular > > server. But how this works with based on facts filter. Correct if am > > wrong. > > > > > > Regards > > Ravi > > > > -- > > > > --- > > You received this message because you are subscribed to the Google Groups > > "mcollective-users" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [email protected]. > > For more options, visit https://groups.google.com/d/optout. > > > -- > R.I.Pienaar / www.devco.net / @ripienaar > > -- > > --- > You received this message because you are subscribed to a topic in the > Google Groups "mcollective-users" group. > To unsubscribe from this topic, visit https://groups.google.com/d/ > topic/mcollective-users/nkKw0Mikhjw/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- --- You received this message because you are subscribed to the Google Groups "mcollective-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
