Database Monitoring for AWS Aurora PostgreSQL

Atatus Database Monitoring provides comprehensive visibility for your AWS Aurora PostgreSQL-compatible databases, offering valuable insights into key metrics such as query performance, query samples, execution plans, connection details, system statistics, and Aurora-specific storage engine telemetry.

To enable Database Monitoring, the Agent gathers telemetry by accessing the database as a read-only user. Follow these steps to configure Database Monitoring for your PostgreSQL database:

• Enable Performance Schema and it's configuration

• Setup Database Access for the Agent

  • Postgres ≥ 10
  • Postgres 9.6

• Install Atatus Infrastructure Agent

Enable Performance Schema and it's configuration

To gather query metrics, samples, and execution plans, you need to activate the Postgres Performance Schema and set up the required Performance Schema Options. This can be done through the command line or by adjusting the configuration files (e.g., postgresql.conf):

Setup Database Access for the Agent

• To connect to the database, use a superuser account (or one with the necessary privileges). For example, for the postgres database, connect as the postgres superuser using psql:

  psql -h mydb.example.com -d postgres -U postgres
  

Postgres ≥ 10

1. Create the atatus user and grant basic permissions:

   CREATE USER atatus WITH password '<UNIQUEPASSWORD>';
   

2. Create the following schema in every database:

   CREATE SCHEMA atatus;
   GRANT USAGE ON SCHEMA atatus TO atatus;
   GRANT USAGE ON SCHEMA public TO atatus;
   GRANT pg_monitor TO atatus;
   CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
   

   Note:

   To collect data or custom metrics that require querying additional tables, you may need to grant the SELECT permission on those tables to the atatus user. For example: grant SELECT on TABLE_NAME to atatus;. Refer to the PostgreSQL custom metric collection documentation for more details.

3. Create the function in every database to enable the Agent to collect explain plans.

   CREATE OR REPLACE FUNCTION atatus.explain_statement(
      l_query TEXT,
      OUT explain JSON
   )
   RETURNS SETOF JSON AS
   $$
   DECLARE
   curs REFCURSOR;
   plan JSON;
   
   BEGIN
      OPEN curs FOR EXECUTE pg_catalog.concat('EXPLAIN (FORMAT JSON) ', l_query);
      FETCH curs INTO plan;
      CLOSE curs;
      RETURN QUERY SELECT plan;
   END;
   $$
   LANGUAGE 'plpgsql'
   RETURNS NULL ON NULL INPUT
   SECURITY DEFINER;
   

Postgres 9.6

1. Create the atatus user and grant basic permissions:

   CREATE USER atatus WITH password '<UNIQUEPASSWORD>';
   

2. Create the following schema in every database:

   CREATE SCHEMA atatus;
   GRANT USAGE ON SCHEMA atatus TO atatus;
   GRANT USAGE ON SCHEMA public TO atatus;
   GRANT SELECT ON pg_stat_database TO atatus;
   CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
   

3. Create functions in every database to enable the Agent to read the full contents of pg_stat_activity and pg_stat_statements:

   CREATE OR REPLACE FUNCTION atatus.pg_stat_activity() RETURNS SETOF pg_stat_activity AS
     $$ SELECT * FROM pg_catalog.pg_stat_activity; $$
   LANGUAGE sql
   SECURITY DEFINER;
   CREATE OR REPLACE FUNCTION atatus.pg_stat_statements() RETURNS SETOF pg_stat_statements AS
       $$ SELECT * FROM pg_stat_statements; $$
   LANGUAGE sql
   SECURITY DEFINER;
   

   Note:

   To collect data or custom metrics that require querying additional tables, you may need to grant the SELECT permission on those tables to the atatus user. For example: grant SELECT on TABLE_NAME to atatus;. Refer to the PostgreSQL custom metric collection documentation for more details.

4. Create the function in every database to enable the Agent to collect explain plans.

   CREATE OR REPLACE FUNCTION atatus.explain_statement(
      l_query TEXT,
      OUT explain JSON
   )
   RETURNS SETOF JSON AS
   $$
   DECLARE
   curs REFCURSOR;
   plan JSON;
   
   BEGIN
      OPEN curs FOR EXECUTE pg_catalog.concat('EXPLAIN (FORMAT JSON) ', l_query);
      FETCH curs INTO plan;
      CLOSE curs;
      RETURN QUERY SELECT plan;
   END;
   $$
   LANGUAGE 'plpgsql'
   RETURNS NULL ON NULL INPUT
   SECURITY DEFINER;
   

Verify

To verify the permissions are correct, run the following commands to confirm the Agent user is able to connect to the database and read the core tables:

psql -h localhost -U atatus postgres -A \
  -c "select * from pg_stat_database limit 1;" \
  && echo -e "\e[0;32mPostgres connection - OK\e[0m" \
  || echo -e "\e[0;31mCannot connect to Postgres\e[0m"

psql -h localhost -U atatus postgres -A \
  -c "select * from pg_stat_activity limit 1;" \
  && echo -e "\e[0;32mPostgres pg_stat_activity read OK\e[0m" \
  || echo -e "\e[0;31mCannot read from pg_stat_activity\e[0m"

psql -h localhost -U atatus postgres -A \
  -c "select * from pg_stat_statements limit 1;" \
  && echo -e "\e[0;32mPostgres pg_stat_statements read OK\e[0m" \
  || echo -e "\e[0;31mCannot read from pg_stat_statements\e[0m"

Configure Atatus Infrastructure Agent

1. To enable Database Monitoring for your databases, You should install the Atatus Infrastructure agent in your host machine.

2. Copy the PostgreSQL example configuration file.

   copy

   cd /etc/atatus-infra-agent/conf.d/postgresql.d/
   sudo cp postgresql.yml.template postgresql.yml
   

3. Update PostgreSQL Configuration File:

Add the following configuration to /etc/atatus-infra-agent/conf.d/postgresql.d/postgresql.yml:

  metrics:
    - hosts: ["postgres://127.0.0.1:5432"]
      username: atatus
      password: <UNIQUEPASSWORD>
      dbm: true

  logs:
   - type: log

4. Restart the atatus infrastructure agent and PostgreSQL service.

  sudo service postgresql restart
  sudo service atatus-infra-agent restart