<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Mike, I hope some of the answers below will shed more light on what you're asking about. On 19.03.2013 03:57, Mike Sam wrote: > Hi Guys, > > I have a couple of questions that I wanted to ask you. > > 1> Why was zookeper removed in juju-core and replaced with mongodb? It was a design decision. Mostly related with instability and issues with zookeeper. Cannot be more specific, perhaps you should ask Gustavo Niemeyer. > > 2> How do you do distributed coordination with mongodb? like how do you do distributed locks and do not worry about race conditions for instance? in other words, do you even need zookeeper type of coordination for juju? Most of the coordination with mongodb in juju-core is done with watchers and mgo transactions. Since juju is a distributed system aiming to scale to 100K nodes or more there are a lot of issues with concurrency and race conditions, we need a central place to sync what juju knows about the environment and get notified about changes. > > 3> Juju currently does not support multiple units per machine but if you had to guess for now, how would you go about supporting this for juju? what is your take on it? what's ur biggest concern to support this with the current design (if any)? Co-location of services on the same machine has been one of the most requested features. There are plans to support this in the future, but not before we have the LXC (local) provider in place and solve issues with networking (you basically need to implement more or less what you have in clouds already, but locally). > > Thanks, > Mike > > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - <a class="moz-txt-link-freetext" href="http://www.enigmail.net/">http://www.enigmail.net/</a> iQEcBAEBAgAGBQJRSGCNAAoJENzxV2TbLzHwlpoIAKDf/VBT72I8MOtAoQzERD6s TS7VR1f9XMB1zFJ2aHFbHm95MqJ5QAyDoTGas+FaIk/PvssxGmTmkwlxKxSA32t0 z10Hsy4EombLqDOxbOzglR2dVtwV6k4ukhHQ+DcZ/eECxRpZniXQKQwBlfCWf14i Q7y3iBdeM9o12+M/5yH5aPqIG4Qx/6PVtj+Kkg3BLpqnWMFjj8wynIXhmjyhG3Kc BkQiZcIZ0nsDJoq70majroworACrW5uOGKnNr7sclYT9YRn6b0EmP3rCPyIuNu9F xkeTc1QvZ7M9boM3lIrlBOQbgXjETDRRnzJkzyuF/dm8uM1KSkA8KzZoG+wjsqM= =xRYp -----END PGP SIGNATURE----- </body> </html>