yb_servers() function [YSQL] - Yugabyte Db

Synopsis

yb_servers() is a function that returns a list of all the nodes in your cluster and their location.

Instructions

The function returns the following information.

Name	Description
host	Internal IP address of the node.
port	Port at which the service will accept connections.
num_connections	Number of active connections to the node.
node_type	Type of the node. One of `primary`,`readreplica` .
cloud	Name of cloud provider. For example, `aws`, `gcp`.
region	Name of the region in which the node is located. For example, `us-east-1`.
zone	Name of the zone in which the node is located. For example, `us-east-1a`.
public_ip	Externally accessible public IP address of the node.
uuid	A UUID that uniquely identifies the node.

Example

For a 6-node cluster spread across 3 zones in aws.west, you should see an output similar to the following:

sql

SELECT * FROM yb_servers();

output

   host    | port | cxn | node_type | cloud | region |  zone  | public_ip |               uuid
-----------+------+-----------------+-----------+-------+--------+--------+-----------+----------------------
 127.0.0.1 | 5433 |   0 | primary   | aws   | west   | zone-a | 127.0.0.1 | d42d033f334242b2becbc43e028f64a2
 127.0.0.2 | 5433 |   0 | primary   | aws   | west   | zone-b | 127.0.0.2 | 8ab7569823c24d38a48ca2cd1e32ea18
 127.0.0.3 | 5433 |   0 | primary   | aws   | west   | zone-c | 127.0.0.3 | bf07b83fe52c479694d127948718dff3
 127.0.0.4 | 5433 |   0 | primary   | aws   | west   | zone-a | 127.0.0.4 | 7e4abfe19eb74c18a352fbfe99168372
 127.0.0.5 | 5433 |   0 | primary   | aws   | west   | zone-b | 127.0.0.5 | e3680e180e7046f287476fea45feef5e
 127.0.0.6 | 5433 |   0 | primary   | aws   | west   | zone-c | 127.0.0.6 | 80f5eb8622104851b7871a86fc66b5a5

Which server am I connected to?

yb_servers() exposes all nodes, with their placement, and PostgreSQL inet_server_port() exposes the server endpoint you are connected to, so joining both:

sql

with yb_servers as (
       select host,port,cloud,region,zone from yb_servers()
   ), my_connection as (
     select host(inet_server_addr()) host, inet_server_port() port ,'<<- you are here' as inet_server)
select * from yb_servers natural left join my_connection;

output


      host      | port | cloud |   region   |    zone     |   inet_server
----------------+------+-------+------------+-------------+------------------
 172.129.25.209 | 5433 | aws   | eu-west-1  | eu-west-1a  | <<- you are here
 172.125.42.26  | 5433 | aws   | ap-south-1 | ap-south-1b |
 172.121.27.101 | 5433 | aws   | us-east-2  | us-east-2a  |

(3 rows)