Roman, The event life-cycle for charms is documented at https://jujucharms.com/docs/devel/developer-event-cycle
Those are the low-level Juju events that are triggered on unit (~machine) level state changes, like units being added or removed, but note that the charms for Bigtop components are using the reactive pattern that abstracts that to some degree to enable the charm code to use more fine-grained, semantically meaningful states, so you won't see direct references to those hooks in the code in the Bigtop repo. However, from the point of view of this question, I don't think it matters; the [name]-relation-departed hook pretty much exactly maps to the "decrease_quorum" handler that Pete mentioned. On Mon, Jun 13, 2016 at 4:16 PM, Roman Shaposhnik <[email protected]> wrote: > On Mon, Jun 13, 2016 at 6:45 AM, MrAsanjar . <[email protected]> wrote: > > *Roman,* > > *If zookeeper charm has been developed correctly, as PEERS in > > methadata.yaml, everytime* > > *any member of zookeeper quorum terminates, a zookeeper-quorum-departed > > event will be send to all* > > *other services (i.e. HBase).* > > > > ``` > > tags: ["bigdata", "hadoop", "apache"] > > > > provides: > > zookeeper: > > interface: zookeeperpeers: > > quorum: > > interface: zookeeper-quorum > > > > ``` > > Ok, then somebody has to educate me on the lifecycle of dependencies > between > different charms. What's a good document to read? What are good > existing examples > of Charms outside of Hadoop ecosystem with non-trividal dependencies like > that? > > Thanks, > Roman. >
