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1. Create a 3 node cluster with replication factor 3
We will use the
yb-ctl utility located in the
bin directory of the YugaByte DB package to create and administer a local cluster. The default data directory used is
/tmp/yugabyte-local-cluster. You can change this directory with the
--data_dir option. Detailed output for the create command is available in yb-ctl Reference.
$ ./bin/yb-ctl --rf 3 create
You can now check
/tmp/yugabyte-local-cluster to see
node-i directories created where
i represents the
node_id of the node. Inside each such directory, there will be 2 disks
disk2 to highlight the fact that YugaByte DB can work with multiple disks at the same time. Note that the IP address of
node-i is by default set to
2. Check cluster status with yb-ctl
Run the command below to see that we now have 3
yb-master processes and 3
yb-tserver processes running on this localhost. Roles played by these processes in a YugaByte cluster (aka Universe) is explained in detail here.
$ ./bin/yb-ctl status
2019-01-29 20:42:43,425 INFO: Server is running: type=master, node_id=1, PID=13668, admin service=http://127.0.0.1:7000 2019-01-29 20:42:43,432 INFO: Server is running: type=master, node_id=2, PID=13671, admin service=http://127.0.0.2:7000 2019-01-29 20:42:43,439 INFO: Server is running: type=master, node_id=3, PID=13674, admin service=http://127.0.0.3:7000 2019-01-29 20:42:43,446 INFO: Server is running: type=tserver, node_id=1, PID=13677, admin service=http://127.0.0.1:9000, cql service=127.0.0.1:9042, redis service=127.0.0.1:6379 2019-01-29 20:42:43,453 INFO: Server is running: type=tserver, node_id=2, PID=13680, admin service=http://127.0.0.2:9000, cql service=127.0.0.2:9042, redis service=127.0.0.2:6379 2019-01-29 20:42:43,460 INFO: Server is running: type=tserver, node_id=3, PID=13687, admin service=http://127.0.0.3:9000, cql service=127.0.0.3:9042, redis service=127.0.0.3:6379
3. Check cluster status with Admin UI
Node 1’s master Admin UI is available at http://127.0.0.1:7000 and the tserver Admin UI is available at http://127.0.0.1:9000. You can visit the other nodes’ Admin UIs by using their corresponding IP addresses.
3.1 Overview and Master status
Node 1’s master Admin UI home page shows that we have a cluster (aka a Universe) with
Replication Factor of 3 and
Num Nodes (TServers) as 3. The
Num User Tables is 0 since there are no user tables created yet. YugaByte DB version number is also shown for your reference.
The Masters section highlights the 3 masters along with their corresponding cloud, region and zone placement.
3.2 TServer status
Clicking on the
See all nodes takes us to the Tablet Servers page where we can observe the 3 tservers along with the time since they last connected to this master via their regular heartbeats. Since there are no user tables created yet, we can see that the
Load (Num Tablets) is 0 across all the 3 tservers. As new tables get added, new tablets (aka shards) will get automatically created and distributed evenly across all the available tablet servers.