Configuring pgBouncer

You must configure pgBouncer to work with the PEM database server. In our example, we will run pgBouncer as the enterprisedb system user. The following steps outline the process of configuring pgBouncer (version >= 1.9).

  1. Open a terminal window and navigate into the pgBouncer directory.

  2. Change the owner of the etc directory for pgBouncer (where pgbouncer.ini resides) to enterprisedb, and change the directory permissions to 0700. For example:

    $ chown enterprisedb:enterprisedb /etc/edb/pgbouncer1.9
    $ chmod 0700 /etc/edb/pgbouncer1.9
    
  3. Change the contents of the pgbouncer.ini or edb-pgbouncer.ini file as follows:

    [databases]
    ;; Change the pool_size according to maximum connections allowed
    ;; to the PEM database server as required.
    ;; 'auth_user' will be used for authenticate the db user (proxy
    ;; agent user in our case)
    pem = port=5444 host=/tmp dbname=pem auth_user=pgbouncer pool_size=80 pool_mode=transaction
    * = port=5444 host=/tmp dbname=pem auth_user=pgbouncer pool_size=10
    [pgbouncer]
    logfile = /var/log/edb/pgbouncer1.9/edb-pgbouncer-1.9.log
    pidfile = /var/run/edb/pgbouncer1.9/edb-pgbouncer-1.9.pid
    listen_addr = *
    ;; Agent needs to use this port to connect the pem database now
    listen_port = 6432
    ;; Require to support for the SSL Certificate authentications
    ;; for PEM Agents
    client_tls_sslmode = require
    ;; These are the root.crt, server.key, server.crt files present
    ;; in the present under the data directory of the PEM database
    ;; server, used by the PEM Agents for connections.
    client_tls_ca_file = /var/lib/edb/as11/data/root.crt
    client_tls_key_file = /var/lib/edb/as11/data/server.key
    client_tls_cert_file = /var/lib/edb/as11/data/server.crt
    ;; Use hba file for client connections
    auth_type = hba
    ;; Authentication file, Reference:
    ;; https://pgbouncer.github.io/config.html#auth_file
    auth_file = /etc/edb/pgbouncer1.9/userlist.txt
    ;; HBA file
    auth_hba_file = /etc/edb/pgbouncer1.9/hba_file
    ;; Use pem.get_agent_pool_auth(TEXT) function to authenticate
    ;; the db user (used as a proxy agent user).
    auth_query = SELECT * FROM pem.get_agent_pool_auth($1)
    ;; DB User for administration of the pgbouncer
    admin_users = pem_admin1
    ;; DB User for collecting the statistics of pgbouncer
    stats_users = pem_admin1
    server_reset_query = DISCARD ALL
    ;; Change based on the number of agents installed/required
    max_client_conn = 500
    ;; Close server connection if its not been used in this time.
    ;; Allows to clean unnecessary connections from pool after peak.
    server_idle_timeout = 60
    
  4. Use the following command to create and update the /etc/edb/pgbouncer1.9/userlist.txt authentication file for pgBouncer:

    pem=# COPY (
       SELECT 'pgbouncer'::TEXT, 'pgbouncer_password'
       UNION ALL
       SELECT 'pem_admin1'::TEXT, 'pem_admin1_password'
    ) TO '/etc/edb/pgbouncer1.9/userlist.txt'
        WITH (FORMAT CSV, DELIMITER ' ', FORCE_QUOTE *);
    COPY 2
    
NOTE: A super user cannot invoke the PEM authentication query function pem.get_proxy_auth(text). If the pem_admin user is a super user, you must add the password to the authentication file, which is enterprisedb in the above example.
  1. Create an HBA file (/etc/edb/pgbouncer1.9/hba_file) for pgBouncer that contains the following content:

    # Use authentication method md5 for the local connections to
    # connect pem database & pgbouncer (virtual) database.
    local pgbouncer all md5
    
    # Use authentication method md5 for the remote connections to
    # connect to pgbouncer (virtual database) using enterprisedb
    # user.
    host pgbouncer,pem pem_admin1 0.0.0.0/0 md5
    # Use authentication method cert for the TCP/IP connections to
    # connect the pem database using pem_agent_user1
    hostssl pem pem_agent_user1 0.0.0.0/0 cert
    
  2. Change the owner of the HBA file (/etc/edb/pgbouncer1.9/hba_file) to enterprisedb, and change the directory permissions to 0600. For example:

    $ chown enterprisedb:enterprisedb /etc/edb/pgbouncer1.9/hba_file
    $ chmod 0600 /etc/edb/pgbouncer1.9/hba_file
    
  3. Enable the pgBouncer service, and start the service. For example:

    $ systemctl enable edb-pgbouncer-1.9
    Created symlink from /etc/systemd/system/multi-user.target.wants/edb-pgbouncer-1.9.service to /usr/lib/systemd/system/edb-pgbouncer-1.9.service.
    $ systemctl start edb-pgbouncer-1.9