This would be great, as I’m running into massive issues trying to get couchdb to cluster in an automated fashion, with bigcouch this was no problem because you could simply use an init container on kubernetes to craft the http call to the /nodes endpoint to add the current nodes hostname, although adapting the http call to couchdb ie 5986/_nodes works from the init container the same, it only works for the initial cluster, after creating the initial cluster trying to add a new node by adding a new node to the nodes db fails to contact the node at any time in the future, but does create the record. This makes adding a node to a cluster in an automated fashion seemingly impossible. :(
I have tried also using the official _setup endpoints but those fail completely because the add_node call is made before the new couch node is started, when failing to contact the node the entire operation seems to be ignored rather than trying again in the near future. I’m considering just going back to bigcouch since it’s broken ops automation entirely for us :( -- Joe Black From: Adam Kocoloski <kocol...@apache.org> Reply: dev@couchdb.apache.org <dev@couchdb.apache.org>> Date: October 6, 2016 at 9:57:55 PM To: dev@couchdb.apache.org <dev@couchdb.apache.org>> Subject: Checking for cluster peers using SRV records on startup Hi all, Lately I’ve been thinking about how to ease the onramp for users to get a clustered CouchDB setup running. I think the Kubernetes work shows a lot of promise. One of the aspects of that work is the service discovery element; each node in a cluster should be able to automatically find its peers and connect to them. Kubernetes accomplishes this using SRV records; a DNS lookup for a given named service will return the FQDNs of all the live members of the “Pet Set”. The SRV approach is enough of a standard[1] that I wonder if we ought to code for it directly in mem3. It’d eliminate the need for a “sidecar” container in Kubernetes deployments and I can imagine that it will prove more generally useful. The idea would be for mem3 to check if the CouchDB node is running in distributed node, and if it is, fire off a DNS lookup on the domain name, then attempt to connect with any other targets that are included in the record set in the DNS response. What do you think? If no one objects I’ll file a JIRA and see what we come up with. Adam [1]: https://tools.ietf.org/html/rfc2782
