Stacked services are applications that are running on the same system, or node. Scuba consists of the following services that can be run on individual systems, or stacked on a single node:
config node — Node from which you administer the cluster. MySQL database (DB) is only installed on this node for storage of Scuba metadata. Configure this node first.
API node — Serves Scuba application, merges results of queries from data and string nodes, and then presents those results. Nginx is only installed on the api node.
import node — Polls data repositories (S3, Azure, local file system), downloads new files, processes the data and then sends to data and string tiers, as appropriate.
data node — Data storage, must have enough space to accommodate all events and stream simultaneous query results.
string node — String storage for the active strings in the dataset, stored in compressed format. Requires sufficient memory to hold the working set of strings accessed during queries.
listener node — If applicable, streams live data from the web or cloud; also known as streaming ingest.