Hi guys. Moving forward with understanding how CouchDB works when working as a cluster I've reached the add/remove nodes step and I've seen the following situations in which I'd like to know what do them mean and if there's something to take care to avoid errors or unexpected behaviours.
First situation: Having a cluster of 4 nodes, all up and connected (i.e: they both appear in the all_nodes and cluster_nodes sections of the _membership endpoint's response), if I ask for any of them to be deleted (issuing a DELETE against the /_nodes database with its id), it is removed from the cluster_nodes section and the cluster seems to be working, possibly because it can still achieve consistency. Is this situation something considered? What does it exactly mean to be part of all_nodes but not cluster_nodes? Second one: Having same setup as above, I bring down a node and then issue the DELETE request to have it removed both from all_nodes and cluster_nodes sections. If I then bring the node up again it automatically appears on the all_nodes section. It only happens if the disk is still available (i.e, all data it used to have), if I completely replace the disk with a new, empty one, when I bring it online it does nothing and I have to ask the cluster to join it by running a PUT request against the /_nodes db. I understand that some information is persisted into disk that allows it to automatically join the cluster. I'd like to have a clearer picture of what it means to appear in the all_nodes and cluster_nodes and each situation's considerations as I can't find it documented anywhere. (i.e, if in all_nodes but not in cluster_nodes it means it cannot...). Thanks! -- [image: Cabify - Your private Driver] <http://www.cabify.com/> *Carlos Alonso* Data Engineer Madrid, Spain [email protected] Prueba gratis con este código #CARLOSA6319 <https://cabify.com/i/carlosa6319> [image: Facebook] <http://cbify.com/fb_ES>[image: Twitter] <http://cbify.com/tw_ES>[image: Instagram] <http://cbify.com/in_ES>[image: Linkedin] <https://www.linkedin.com/in/mrcalonso> -- Este mensaje y cualquier archivo adjunto va dirigido exclusivamente a su destinatario, pudiendo contener información confidencial sometida a secreto profesional. No está permitida su reproducción o distribución sin la autorización expresa de Cabify. Si usted no es el destinatario final por favor elimínelo e infórmenos por esta vía. This message and any attached file are intended exclusively for the addressee, and it may be confidential. You are not allowed to copy or disclose it without Cabify's prior written authorization. If you are not the intended recipient please delete it from your system and notify us by e-mail.
