PostgreSQL On Amazon EC2 and Enterprise Query Log Ingestion¶

Before performing query log ingestion (QLI), perform the QLI setup for PostgreSQL on EC2 or EDB Postgres Server (PostgreSQL Enterprise). Both the Amazon EC2 and EDB deployments support log rotation. You can choose one of the following ways to perform the QLI setup:

EC2:

CSV Logging without Log Rotation

CSV Logging with Log Rotation

EDB Postgres Server:

EDB Audit Logs without Log Rotation

EDB Postgres Server with Audit Log Rotation

CSV Logging without Log Rotation¶

To configure QLI based on CSV logging with no log rotation:

Change the server configuration in postgresql.conf and enable CSV logging as described below.

# Set the logging details for postgresql.conf file and reload the file (changing logging_collector needs a restart).

log_destination ='csvlog'

log_directory = 'pg_log'

logging_collector = on

log_filename = 'postgresql'

log_duration = on             # Should be enabled only if log_min_duration_statement is not set to 0

log_min_duration_statement = 0

log_error_verbosity = verbose      # terse, default, or verbose messages

log_hostname = on

log_statement = 'all'      # none, ddl, mod, all

log_rotation_age = 0

log_rotation_size = 0

log_min_error_statement = info

Reload the updated postgresql.conf.
SELECT pg_reload_conf();

Note

The log_rotation_age = 0 and log_rotation_size = 0 properties stop the log rotation and write all logs to the same file (table). Setting the log_min_duration_statement property to a value greater than zero forcefully logs the query text; however, the log_duration property doesn’t.

Install the file_fdw extension (contrib package is required), create a foreign file server and a foreign table, and link it to the log file name provided in the postgresql.conf file.

CREATE EXTENSION file_fdw;

CREATE SERVER pglog FOREIGN DATA WRAPPER file_fdw;

CREATE FOREIGN TABLE public.postgres_log (
    log_time timestamp(3) with time zone,
    user_name text,
    database_name text,
    process_id integer,
    connection_from text,
    session_id text,
    session_line_num bigint,
    command_tag text,
    session_start_time timestamp with time zone,
    virtual_transaction_id text,
    transaction_id bigint,
    error_severity text,
    sql_state_code text,
    message text,
    detail text,
    hint text,
    internal_query text,
    internal_query_pos integer,
    context text,
    query text,
    query_pos integer,
    location text,
    application_name text,
    backend_type text,
    empty_column text,
    column_with_zeroes text
    )
    SERVER pglog
    OPTIONS (filename 'pg_log/postgresql.csv', format 'csv');

Create a view for Alation to retrieve query logs from.

CREATE VIEW public.alation_postgres_logv AS
    SELECT
      session_id AS sessionID,
      user_name AS userName,
      session_start_time AS sessionStartTime,
      session_start_time AS startTime,
      virtual_transaction_id AS transactionid,
      message AS queryString,
      'N' AS cancelled,
      database_name AS defaultDatabases
    FROM public.postgres_log;

Note

The above view applies to PostgreSQL OCF connector version 1.1.9. If you upgrade from an earlier version to version 1.1.9, create a new view using the above template or change your view with a CREATE OR REPLACE query using the above template.

Grant the Alation service account access to the QLI view.

Grant SELECT on public.alation_postgres_logv to {Alation Service Account}

Update the Query Log Ingestion tab of the Settings page of your OCF data source. Refer Configure QLI in Alation User Interface.

CSV Logging with Log Rotation¶

To conveniently retain logs for, for example, seven days only through automatic truncation, you can consider creating seven child tables for a master table. The process would typically use this workflow:

Open the postgresql.conf file, perform the following way:

log_destination = 'csvlog'

log_filename = 'postgresql-%a'  # Keep 7d of logs in files 'postgresql-Mon.csv' etc.

log_directory ='pg_log'

logging_collector = on

log_duration = on      # Should be enabled only if log_min_duration_statement is not set to 0

log_min_duration_statement = 0

log_error_verbosity = verbose     # terse, default, or verbose messages

log_hostname = on

log_statement = 'all'    # none, ddl, mod, all

log_truncate_on_rotation = on

log_rotation_age = 1440

log_rotation_size = 0

log_min_error_statement = info

Note

To maintain logs for the seven days, name one log file per day such as postgresql-Mon and postgresql-Tue. To automatically overwrite last week’s log with the current week, set log_filename to postgresql-%a, log_truncate_on_rotation to on, and log_rotation_age to 1440.

The log_rotation_age = 0 and log_rotation_size = 0 properties stop the log rotation and write all logs to the same file (table). Setting the log_min_duration_statement property to a value greater than zero forcefully logs the query text; however, the log_duration property doesn’t.

Reload the updated postgresql.conf.
SELECT pg_reload_conf();

Install the file_fdw extension (contrib package is required), create a foreign file server and a foreign table, and link it to the log file name configured in the previous step.

CREATE EXTENSION file_fdw;
CREATE SERVER pglog FOREIGN DATA WRAPPER file_fdw;
CREATE TABLE public.postgres_log (
  log_time timestamp(3) with time zone,
  user_name text,
  database_name text,
  process_id integer,
  connection_from text,
  session_id text,
  session_line_num bigint,
  command_tag text,
  session_start_time timestamp with time zone,
  virtual_transaction_id text,
  transaction_id bigint,
  error_severity text,
  sql_state_code text,
  message text,
  detail text,
  hint text,
  internal_query text,
  internal_query_pos integer,
  context text,
  query text,
  query_pos integer,
  location text,
  application_name text

CREATE FOREIGN TABLE public.postgres_log_mon (
        log_time timestamp(3) with time zone,
    user_name text,
    database_name text,
    process_id integer,
    connection_from text,
    session_id text,
    session_line_num bigint,
    command_tag text,
    session_start_time timestamp with time zone,
    virtual_transaction_id text,
    transaction_id bigint,
    error_severity text,
    sql_state_code text,
    message text,
    detail text,
    hint text,
    internal_query text,
    internal_query_pos integer,
    context text,
    query text,
    query_pos integer,
    location text,
    application_name text
    ) SERVER pglog
      OPTIONS (filename 'pg_log/postgresql-Mon.csv', format 'csv');
ALTER TABLE public.postgres_log_mon INHERIT public.postgres_log;

Repeat Step 3 for the remaining days of the week (Tuesday to Sunday).

Create a view for Alation to retrieve the query logs.

CREATE VIEW public.alation_postgres_logv AS
SELECT
  session_id AS sessionID,
  user_name AS userName,
  session_start_time AS sessionStartTime,
  session_start_time AS startTime,
  virtual_transaction_id AS transactionid,
  message AS queryString,
  'N' AS cancelled,
  database_name AS defaultDatabases
FROM public.postgres_log;
Note

The above view applies to PostgreSQL OCF connector version 1.1.9. If you upgrade from an earlier version to version 1.1.9, create a new view using the above template or change your view with a CREATE OR REPLACE query using the above template.

Grant the Alation service account access to the QLI view.

GRANT SELECT ON public.alation_postgres_logv TO {Alation Service Account}

Update the Query Log Ingestion tab of the Settings page of your OCF data source. Refer Configure QLI in Alation User Interface.

EDB Audit Logs without Log Rotation¶

Perform these steps to configure QLI based on EDB Audit logs without log rotation:

Change the server configuration (postgresql.conf) and enable CSV logging.

# set in postgresql.conf + restart/reload server (changing logging_collector needs restart)
#------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#------------------------------------------------------------

# - Where to Log -

logging_collector = on

#------------------------------------------------------------
# EDB AUDIT
#------------------------------------------------------------

edb_audit = 'csv'                       # none, csv or xml

# These are only used if edb_audit is not none:
edb_audit_directory = 'edb_audit'       # Directory where the log files are written
                                        # Can be absolute or relative to PGDATA

edb_audit_filename = 'postgresaudit'    # Audit file name pattern.
                                        # Can include strftime() escapes

edb_audit_rotation_day = 'none'         # Automatic rotation of log files based
                                        # on day of week. none, every, sun,
                                        # mon, tue, wed, thu, fri, sat

edb_audit_rotation_size = 0             # Automatic rotation of log files will
                                        # happen after this many megabytes (MB)
                                        # of log output.  0 to disable.

edb_audit_rotation_seconds = 0          # Automatic log file rotation will
                                        # happen after this many seconds.

edb_audit_connect = 'all'               # none, failed, all

#edb_audit_disconnect ='none'           # none, all

edb_audit_statement = 'all'             # none, dml, ddl, select, error, rollback, all

#edb_audit_tag = ''

Reload the updated postgresql.conf using the following command:
SELECT pg_reload_conf();

Note

The properties edb_audit_rotation_size = 0, edb_audit_rotation_day = 'none', and edb_audit_rotation_seconds = 0 stop the rotation and write all logs to the same file (table).

Install the file_fdw extension (contrib package is required), create a foreign file server and a foreign table, and link it to the log file name configured in the previous step.

CREATE EXTENSION file_fdw;
CREATE SERVER pglog FOREIGN DATA WRAPPER file_fdw;
CREATE FOREIGN TABLE public.postgres_log (
  user_name text,
  database_name text,
  process_id integer,
  connection_from text,
  session_id text,
  session_line_num bigint,
  command_tag text,
  session_start_time timestamp with time zone,
  virtual_transaction_id text,
  transaction_id bigint,
  error_severity text,
  sql_state_code text,
  message text,
  detail text,
  hint text,
  internal_query text,
  internal_query_pos integer,
  context text,
  query text,
  query_pos integer,
  location text,
  application_name text,
  extra text
) SERVER pglog
OPTIONS (
  filename 'edb_audit/postgresaudit.csv', format 'csv');

Create a view for Alation to retrieve query logs from.

CREATE VIEW public.alation_postgres_logv AS
SELECT
  session_id AS sessionID,
  user_name AS userName,
  session_start_time AS sessionStartTime,
  session_start_time AS startTime,
  virtual_transaction_id AS transactionid,
  message AS queryString,
  'N' AS cancelled,
  database_name AS defaultDatabases
FROM public.postgres_log;
Note

The above view applies to PostgreSQL OCF connector version 1.1.9. If you upgrade from an earlier version to version 1.1.9, create a new view using the above template or change your view with a CREATE OR REPLACE query using the above template.

Grant the Alation service account access to the QLI view.

Grant SELECT on public.alation_postgres_logv to {Alation Service Account}

Update the Query Log Ingestion tab of the Settings page of your OCF data source. Refer Configure QLI in Alation User Interface.

Note

This log doesn’t log duration.

EDB Postgres Server with Audit Log Rotation¶

(Alation version 4.16)

Perform these steps to configure QLI based on EDB Postgres Server with Audit log rotation:

Change the server configuration (postgresql.conf) and enable CSV logging.

# set in postgresql.conf + restart/reload server (changing logging_collector needs restart)
#-----------------------------------------------------------------------------------------
#ERROR REPORTING AND LOGGING
#-----------------------------------------------------------------------------------------
# - Where to Log -
logging_collector = on
#-----------------------------------------------------------------------------------------
# EDB AUDIT
#-----------------------------------------------------------------------------------------
edb_audit = 'csv'                                   # none, csv or xml

# These are only used if edb_audit is not none:

edb_audit_directory = 'edb_audit'                  # Directory where the log files are written
                                                  # Can be absolute or relative to PGDATA

edb_audit_filename = 'audit-%Y-%m-%dT%H:%M:%S'      # Audit file name pattern.
                                                    # Can include strftime() escapes

edb_audit_rotation_day = 'every'                    # Automatic rotation of log files based
                                                    # on day of week. none, every, sun,
                                                    # mon, tue, wed, thu, fri, sat

edb_audit_rotation_size = 0                         # Automatic rotation of log files will
                                                    # happen after this many megabytes (MB)
                                                    # of log output.  0 to disable.

edb_audit_rotation_seconds = 0                      # Automatic log file rotation will
                                                    # happen after this many seconds.

edb_audit_connect = 'all'                           # none, failed, all

#edb_audit_disconnect ='none'                       # none, all

edb_audit_statement = 'all'                         # none, dml, ddl, select, error, rollback, all

#edb_audit_tag = ''                                 # Audit log session tracking tag.

Note

Setting edb_audit_filename = 'audit-%Y-%m-%dT%H:%M:%S' creates a file with name as audit-2017-11-26T11:04:44.csv.
Every file is rolled off due to the configuration edb_audit_rotation_day = 'every'

Reload the updated postgresql.conf using the following command:
SELECT pg_reload_conf();
Create a table to copy logs from csv.

CREATE TABLE public.postgres_log (
  log_time timestamp(3) with time zone,
  user_name text,
  database_name text,
  process_id integer,
  connection_from text,
  session_id text,
  session_line_num bigint,
  command_tag text,
  session_start_time timestamp with time zone,
  virtual_transaction_id text,
  transaction_id bigint,
  error_severity text,
  sql_state_code text,
  message text,
  detail text,
  hint text,
  internal_query text,
  internal_query_pos integer,
  context text,
  query text,
  query_pos integer,
  location text,
  application_name text,
  extra text
);

CREATE TABLE public.postgres_log (
  log_time timestamp(3) with time zone,
  user_name text,
  database_name text,
  process_id integer,
  connection_from text,
  session_id text,
  session_line_num bigint,
  command_tag text,
  session_start_time timestamp with time zone,
  virtual_transaction_id text,
  transaction_id bigint,
  error_severity text,
  sql_state_code text,
  message text,
  detail text,
  hint text,
  internal_query text,
  internal_query_pos integer,
  context text,
  query text,
  query_pos integer,
  location text,
  application_name text,
  statement_type text,
  extra text
);

Create a log rotation config file.

Note

EDB_AUDIT_LOG_DIRECTORY_PATH must have read privileges.

POSTGRES_HOME/bin/edb-psql must have execute privileges.

vi  postgres_audit_log_rotation_config.txt

EDB_AUDIT_LOG_DIRECTORY_PATH=/opt/edb/as<postgres version>/data/edb_audit/
EDB_AUDIT_LOG_FILENAME_PREFIX=audit-
HOST=<postgres server_host>
PORT=<postgres server_port>
USERNAME=<username of your service account>
PASSWORD=<username of your service password>
DATABASE=postgres
POSTGRES_HOME=/opt/edb/as<postgres_version>/

Example

vi  postgres_audit_log_rotation_config.txt

EDB_AUDIT_LOG_DIRECTORY_PATH=/opt/edb/as9.6/data/edb_audit/
EDB_AUDIT_LOG_FILENAME_PREFIX=audit-
HOST=10.11.21.41
PORT=5432
USERNAME=postgres
PASSWORD=hyperbad
DATABASE=postgres
POSTGRES_HOME=/opt/edb/as9.6/

Create a log rotation script. The script will look for yesterday’s log and copies yesterday’s csv to the public.postgres_log file.

Move both the postgres_audit_log_rotation.sh and postgres_audit_log_rotation_config.txt files to {Postgres Installation Directory}/edb/as9.6/bin.

mv postgres_audit_log_rotation.sh opt/edb/as<postgres_version>/bin/.
mv postgres_audit_log_rotation_config.txt opt/edb/as<postgres_version>/bin/.

Provide the execute permission on the postgres_audit_log_rotation.sh file.

chmod +x  {Postgres Installation Directory}/edb/as<*postgres_version*>/bin/postgres_audit_log_rotation.sh
chmod +x  opt/edb/as9.6/bin/postgres_audit_log_rotation.sh

Grant the read permission on the postgres_audit_log_rotation_config.txt file.
chmod 444 opt/edb/as9.6/bin/postgres_audit_log_rotation_config.txt

Create a cron job to run the script at 1 am every day.

This syncs yesterday’s log to public.postgres_log at 1.00 AM.

0 1 * * *   sh {Postgres Installation Directory}/edb/as<*postgres_version*>/bin/postres_audit_log_rotation.sh
{Postgres Installation Directory}/edb/as<*postgres_version*>/bin/postres_audit_log_rotation_config.txt

For example, crontab -e

0 1 * * *   sh /opt/edb/as9.6/bin/postres_audit_log_rotation.sh
/opt/edb/as9.6/bin/postres_audit_log_rotation_config.txt

For Ubuntu Users

For example, crontab -e (Use bash instead of sh)

0 1 * * *   bash /opt/edb/as<postgres_version>/bin/postres_audit_log_rotation.sh
/opt/edb/as<postgres_version>/bin/postres_audit_log_rotation_config.txt

Create a view for Alation to retrieve the query log from.

CREATE VIEW public.alation_postgres_logv AS
SELECT
  session_id AS sessionID,
  user_name AS userName,
  session_start_time AS sessionStartTime,
  session_start_time AS startTime,
  virtual_transaction_id AS transactionid,
  message AS queryString,
  'N' AS cancelled,
  database_name AS defaultDatabases
FROM
  public.postgres_log;

Note

The above view applies to PostgreSQL OCF connector version 1.1.9. If you upgrade from an earlier version to version 1.1.9, create a new view using the above template or change your view with a CREATE OR REPLACE query using the above template.

Grant the Alation service account access to the QLI view.

Grant SELECT on public.alation_postgres_logv to {Alation Service Account}

Update the Query Log Ingestion tab of the Settings page of your OCF data source. Refer Configure QLI in Alation User Interface.

Configure QLI in Alation User Interface¶

For Alation version 2023.3.4 and connector version 1.2.0, see Configure QLI for PostgreSQL on Amazon EC2 and Enterprise section in Version 1.2.0 or Newer

To configure view-based QLI:

Go to the Query Log Ingestion tab of the Settings page of your OCF data source.

Under Connector Settings > Query Extraction, enter the view name as public.alation_postgres_logv in the Table Name field.

Click Save.

PostgreSQL On Amazon EC2 and Enterprise Query Log Ingestion¶

CSV Logging without Log Rotation¶

CSV Logging with Log Rotation¶

EDB Audit Logs without Log Rotation¶

EDB Postgres Server with Audit Log Rotation¶

Configure QLI in Alation User Interface¶

Alation Documentation PDF