Universe creation

Step 1. Start YB-Masters

When creating a YugabyteDB universe, the first step is to bring up sufficient YB-Masters (as many asthe replication factor) with each being told about the others. These YB-Masters initialize themselves with a uniqueUUID, learn about each other and perform a leader election. At the end of this step, one of the masters establishes itself as the leader.

Step 2. Start YB-TServers

The next step is to start as many YB-TServers as there are nodes, with the master addresses beingpassed to them on startup. They start heart-beating to the masters, communicating the fact that theyare alive. The heartbeats also communicate the tablets the YB-TServers are currently hosting andtheir load, but no tablets would exist in the system yet.

An example

Let us illustrate this with our usual example of creating a 4-node YugabyteDB universe with areplication factor of 3. In order to do so, first the three masters are started in the create modeinstructing them to that this is a brand new universe create. This is done explicitly to preventaccidental errors in creating a universe while it is already running.

create_universe_masters

The next step, the masters learn about each other and elect one leader.

create_universe_master_election

The YB-TServers are then started, and they all heartbeat to the YB-Master.

create_universe_tserver_heartbeat