"FATAL: sorry, too many clients already" Displayed When Loading Data for Initialization During PostgreSQL Test

Symptom

During the PostgreSQL test, when a large amount of data is loaded during initialization, for example, when 500 warehouses data is loaded, the message "ERROR: FATAL: sorry, too many clients already" is displayed.

Key Process and Cause Analysis

The amount of loaded data is greater than the value of max_connections in the postgresql.conf file.

Conclusion and Solution

To solve this problem, increase the values of max_connection and idle_in_transaction_session_timeout in the postgresql.conf file.

1. Open the postgresql.conf file.

   vim /data/pgsql/postgresql.conf

2. Press i to enter the insert mode and modify line 64 as follows:

   max_connections = 4096

   Modify line 574 as follows:

   idle_in_transaction_session_timeout = 20000

3. Press Esc, type :wq!, and press Enter to save the file and exit.
4. Restart the database for the modification to take effect.

   /usr/local/pgsql/bin/pg_ctl -D /data/pgsql -l logfile restart

   

   Modify the following directories as required:

   • /usr/local/pgsql/bin/pg_ctl is the installation directory of the PostgreSQL program.
   • /data/pgsql is the data directory of the PostgreSQL database.