Prerequisite Step: Adjust max_connections

Before proceeding with a high availability deployment, you must increase the number of connections that PostgreSQL allows; this is controlled by themax_connections property in PostgreSQL’s postgresql.conf file. You must set this value high enough to account for all of your nodes’ connection pool sizes as well as a buffer for DBAs and automated tools that need to connect directly to the database.

For example, if you have three nodes, each using the default maximumPoolSize setting of 100 (defined in <data-dir>/etc/fabric/nexus-store.properties), we recommend setting max_connections to 350 in the postgresql.conf file.

Failure to complete this step can prevent Nexus Repository nodes from starting and lead to a FATAL: sorry, too many clients already error in PostgreSQL.