Adding upstream version 1.29.3.upstream/1.29.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 1488 insertions, 0 deletions

diff --git a/collectors/python.d.plugin/postgres/Makefile.inc b/collectors/python.d.plugin/postgres/Makefile.inc
new file mode 100644
index 0000000..91a185c
--- /dev/null
+++ b/collectors/python.d.plugin/postgres/Makefile.inc
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# THIS IS NOT A COMPLETE Makefile
+# IT IS INCLUDED BY ITS PARENT'S Makefile.am
+# IT IS REQUIRED TO REFERENCE ALL FILES RELATIVE TO THE PARENT
+
+# install these files
+dist_python_DATA       += postgres/postgres.chart.py
+dist_pythonconfig_DATA += postgres/postgres.conf
+
+# do not install these files, but include them in the distribution
+dist_noinst_DATA       += postgres/README.md postgres/Makefile.inc
+
diff --git a/collectors/python.d.plugin/postgres/README.md b/collectors/python.d.plugin/postgres/README.md
new file mode 100644
index 0000000..dc9b184
--- /dev/null
+++ b/collectors/python.d.plugin/postgres/README.md
@@ -0,0 +1,99 @@
+<!--
+title: "PostgreSQL monitoring with Netdata"
+custom_edit_url: https://github.com/netdata/netdata/edit/master/collectors/python.d.plugin/postgres/README.md
+sidebar_label: "PostgreSQL"
+-->
+
+# PostgreSQL monitoring with Netdata
+
+Collects database health and performance metrics.
+
+## Requirements
+
+-   `python-psycopg2` package. You have to install it manually and make sure that it is available to the `netdata` user, either using `pip`, the package manager of your Linux distribution, or any other method you prefer.
+
+Following charts are drawn:
+
+1.  **Database size** MB
+
+    -   size
+
+2.  **Current Backend Processes** processes
+
+    -   active
+
+3.  **Current Backend Process Usage** percentage
+
+    -   used
+    -   available
+
+4.  **Write-Ahead Logging Statistics** files/s
+
+    -   total
+    -   ready
+    -   done
+
+5.  **Checkpoints** writes/s
+
+    -   scheduled
+    -   requested
+
+6.  **Current connections to db** count
+
+    -   connections
+
+7.  **Tuples returned from db** tuples/s
+
+    -   sequential
+    -   bitmap
+
+8.  **Tuple reads from db** reads/s
+
+    -   disk
+    -   cache
+
+9.  **Transactions on db** transactions/s
+
+    -   committed
+    -   rolled back
+
+10.  **Tuples written to db** writes/s
+
+    -   inserted
+    -   updated
+    -   deleted
+    -   conflicts
+
+11. **Locks on db** count per type
+
+    -   locks
+
+## Configuration
+
+Edit the `python.d/postgres.conf` configuration file using `edit-config` from the Netdata [config
+directory](/docs/configure/nodes.md), which is typically at `/etc/netdata`.
+
+```bash
+cd /etc/netdata   # Replace this path with your Netdata config directory, if different
+sudo ./edit-config python.d/postgres.conf
+```
+
+When no configuration file is found, the module tries to connect to TCP/IP socket: `localhost:5432`.
+
+```yaml
+socket:
+  name         : 'socket'
+  user         : 'postgres'
+  database     : 'postgres'
+
+tcp:
+  name         : 'tcp'
+  user         : 'postgres'
+  database     : 'postgres'
+  host         : 'localhost'
+  port         : 5432
+```
+
+---
+
+[![analytics](https://www.google-analytics.com/collect?v=1&aip=1&t=pageview&_s=1&ds=github&dr=https%3A%2F%2Fgithub.com%2Fnetdata%2Fnetdata&dl=https%3A%2F%2Fmy-netdata.io%2Fgithub%2Fcollectors%2Fpython.d.plugin%2Fpostgres%2FREADME&_u=MAC~&cid=5792dfd7-8dc4-476b-af31-da2fdb9f93d2&tid=UA-64295674-3)](<>)
diff --git a/collectors/python.d.plugin/postgres/postgres.chart.py b/collectors/python.d.plugin/postgres/postgres.chart.py
new file mode 100644
index 0000000..bd28dd9
--- /dev/null
+++ b/collectors/python.d.plugin/postgres/postgres.chart.py
@@ -0,0 +1,1235 @@
+# -*- coding: utf-8 -*-
+# Description: example netdata python.d module
+# Authors: facetoe, dangtranhoang
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from copy import deepcopy
+
+try:
+    import psycopg2
+    from psycopg2 import extensions
+    from psycopg2.extras import DictCursor
+    from psycopg2 import OperationalError
+
+    PSYCOPG2 = True
+except ImportError:
+    PSYCOPG2 = False
+
+from bases.FrameworkServices.SimpleService import SimpleService
+
+DEFAULT_PORT = 5432
+DEFAULT_USER = 'postgres'
+DEFAULT_CONNECT_TIMEOUT = 2  # seconds
+DEFAULT_STATEMENT_TIMEOUT = 5000  # ms
+
+CONN_PARAM_DSN = 'dsn'
+CONN_PARAM_HOST = 'host'
+CONN_PARAM_PORT = 'port'
+CONN_PARAM_DATABASE = 'database'
+CONN_PARAM_USER = 'user'
+CONN_PARAM_PASSWORD = 'password'
+CONN_PARAM_CONN_TIMEOUT = 'connect_timeout'
+CONN_PARAM_STATEMENT_TIMEOUT = 'statement_timeout'
+CONN_PARAM_SSL_MODE = 'sslmode'
+CONN_PARAM_SSL_ROOT_CERT = 'sslrootcert'
+CONN_PARAM_SSL_CRL = 'sslcrl'
+CONN_PARAM_SSL_CERT = 'sslcert'
+CONN_PARAM_SSL_KEY = 'sslkey'
+
+QUERY_NAME_WAL = 'WAL'
+QUERY_NAME_ARCHIVE = 'ARCHIVE'
+QUERY_NAME_BACKENDS = 'BACKENDS'
+QUERY_NAME_BACKEND_USAGE = 'BACKEND_USAGE'
+QUERY_NAME_TABLE_STATS = 'TABLE_STATS'
+QUERY_NAME_INDEX_STATS = 'INDEX_STATS'
+QUERY_NAME_DATABASE = 'DATABASE'
+QUERY_NAME_BGWRITER = 'BGWRITER'
+QUERY_NAME_LOCKS = 'LOCKS'
+QUERY_NAME_DATABASES = 'DATABASES'
+QUERY_NAME_STANDBY = 'STANDBY'
+QUERY_NAME_REPLICATION_SLOT = 'REPLICATION_SLOT'
+QUERY_NAME_STANDBY_DELTA = 'STANDBY_DELTA'
+QUERY_NAME_REPSLOT_FILES = 'REPSLOT_FILES'
+QUERY_NAME_IF_SUPERUSER = 'IF_SUPERUSER'
+QUERY_NAME_SERVER_VERSION = 'SERVER_VERSION'
+QUERY_NAME_AUTOVACUUM = 'AUTOVACUUM'
+QUERY_NAME_DIFF_LSN = 'DIFF_LSN'
+QUERY_NAME_WAL_WRITES = 'WAL_WRITES'
+
+METRICS = {
+    QUERY_NAME_DATABASE: [
+        'connections',
+        'xact_commit',
+        'xact_rollback',
+        'blks_read',
+        'blks_hit',
+        'tup_returned',
+        'tup_fetched',
+        'tup_inserted',
+        'tup_updated',
+        'tup_deleted',
+        'conflicts',
+        'temp_files',
+        'temp_bytes',
+        'size'
+    ],
+    QUERY_NAME_BACKENDS: [
+        'backends_active',
+        'backends_idle'
+    ],
+    QUERY_NAME_BACKEND_USAGE: [
+        'available',
+        'used'
+    ],
+    QUERY_NAME_INDEX_STATS: [
+        'index_count',
+        'index_size'
+    ],
+    QUERY_NAME_TABLE_STATS: [
+        'table_size',
+        'table_count'
+    ],
+    QUERY_NAME_WAL: [
+        'written_wal',
+        'recycled_wal',
+        'total_wal'
+    ],
+    QUERY_NAME_WAL_WRITES: [
+        'wal_writes'
+    ],
+    QUERY_NAME_ARCHIVE: [
+        'ready_count',
+        'done_count',
+        'file_count'
+    ],
+    QUERY_NAME_BGWRITER: [
+        'checkpoint_scheduled',
+        'checkpoint_requested',
+        'buffers_checkpoint',
+        'buffers_clean',
+        'maxwritten_clean',
+        'buffers_backend',
+        'buffers_alloc',
+        'buffers_backend_fsync'
+    ],
+    QUERY_NAME_LOCKS: [
+        'ExclusiveLock',
+        'RowShareLock',
+        'SIReadLock',
+        'ShareUpdateExclusiveLock',
+        'AccessExclusiveLock',
+        'AccessShareLock',
+        'ShareRowExclusiveLock',
+        'ShareLock',
+        'RowExclusiveLock'
+    ],
+    QUERY_NAME_AUTOVACUUM: [
+        'analyze',
+        'vacuum_analyze',
+        'vacuum',
+        'vacuum_freeze',
+        'brin_summarize'
+    ],
+    QUERY_NAME_STANDBY_DELTA: [
+        'sent_delta',
+        'write_delta',
+        'flush_delta',
+        'replay_delta'
+    ],
+    QUERY_NAME_REPSLOT_FILES: [
+        'replslot_wal_keep',
+        'replslot_files'
+    ]
+}
+
+NO_VERSION = 0
+DEFAULT = 'DEFAULT'
+V72 = 'V72'
+V82 = 'V82'
+V91 = 'V91'
+V92 = 'V92'
+V96 = 'V96'
+V10 = 'V10'
+V11 = 'V11'
+
+QUERY_WAL = {
+    DEFAULT: """
+SELECT
+    count(*) as total_wal,
+    count(*) FILTER (WHERE type = 'recycled') AS recycled_wal,
+    count(*) FILTER (WHERE type = 'written') AS written_wal
+FROM
+    (SELECT
+        wal.name,
+        pg_walfile_name(
+          CASE pg_is_in_recovery()
+            WHEN true THEN NULL
+            ELSE pg_current_wal_lsn()
+          END ),
+        CASE
+          WHEN wal.name > pg_walfile_name(
+            CASE pg_is_in_recovery()
+              WHEN true THEN NULL
+              ELSE pg_current_wal_lsn()
+            END ) THEN 'recycled'
+          ELSE 'written'
+        END AS type
+    FROM pg_catalog.pg_ls_dir('pg_wal') AS wal(name)
+    WHERE name ~ '^[0-9A-F]{24}$'
+    ORDER BY
+        (pg_stat_file('pg_wal/'||name)).modification,
+        wal.name DESC) sub;
+""",
+    V96: """
+SELECT
+    count(*) as total_wal,
+    count(*) FILTER (WHERE type = 'recycled') AS recycled_wal,
+    count(*) FILTER (WHERE type = 'written') AS written_wal
+FROM
+    (SELECT
+        wal.name,
+        pg_xlogfile_name(
+          CASE pg_is_in_recovery()
+            WHEN true THEN NULL
+            ELSE pg_current_xlog_location()
+          END ),
+        CASE
+          WHEN wal.name > pg_xlogfile_name(
+            CASE pg_is_in_recovery()
+              WHEN true THEN NULL
+              ELSE pg_current_xlog_location()
+            END ) THEN 'recycled'
+          ELSE 'written'
+        END AS type
+    FROM pg_catalog.pg_ls_dir('pg_xlog') AS wal(name)
+    WHERE name ~ '^[0-9A-F]{24}$'
+    ORDER BY
+        (pg_stat_file('pg_xlog/'||name)).modification,
+        wal.name DESC) sub;
+""",
+}
+
+QUERY_ARCHIVE = {
+    DEFAULT: """
+SELECT
+    CAST(COUNT(*) AS INT) AS file_count,
+    CAST(COALESCE(SUM(CAST(archive_file ~ $r$\.ready$$r$ as INT)),0) AS INT) AS ready_count,
+    CAST(COALESCE(SUM(CAST(archive_file ~ $r$\.done$$r$ AS INT)),0) AS INT) AS done_count
+FROM
+    pg_catalog.pg_ls_dir('pg_wal/archive_status') AS archive_files (archive_file);
+""",
+    V96: """
+SELECT
+    CAST(COUNT(*) AS INT) AS file_count,
+    CAST(COALESCE(SUM(CAST(archive_file ~ $r$\.ready$$r$ as INT)),0) AS INT) AS ready_count,
+    CAST(COALESCE(SUM(CAST(archive_file ~ $r$\.done$$r$ AS INT)),0) AS INT) AS done_count
+FROM
+    pg_catalog.pg_ls_dir('pg_xlog/archive_status') AS archive_files (archive_file);
+
+""",
+}
+
+QUERY_BACKEND = {
+    DEFAULT: """
+SELECT
+    count(*) - (SELECT  count(*)
+                FROM pg_stat_activity
+                WHERE state = 'idle')
+      AS backends_active,
+    (SELECT count(*)
+     FROM pg_stat_activity
+     WHERE state = 'idle')
+      AS backends_idle
+FROM pg_stat_activity;
+""",
+}
+
+QUERY_BACKEND_USAGE = {
+    DEFAULT: """
+SELECT
+    COUNT(1) as used,
+    current_setting('max_connections')::int - current_setting('superuser_reserved_connections')::int
+    - COUNT(1) AS available
+FROM pg_catalog.pg_stat_activity
+WHERE backend_type IN ('client backend', 'background worker');
+""",
+    V10: """
+SELECT
+    SUM(s.conn) as used,
+    current_setting('max_connections')::int - current_setting('superuser_reserved_connections')::int
+    - SUM(s.conn) AS available
+FROM (
+    SELECT 's' as type, COUNT(1) as conn
+    FROM pg_catalog.pg_stat_activity
+    WHERE backend_type IN ('client backend', 'background worker')
+    UNION ALL
+    SELECT 'r', COUNT(1) 
+    FROM pg_catalog.pg_stat_replication
+) as s;
+""",
+    V92: """
+SELECT
+    SUM(s.conn) as used,
+    current_setting('max_connections')::int - current_setting('superuser_reserved_connections')::int
+    - SUM(s.conn) AS available
+FROM (
+    SELECT 's' as type, COUNT(1) as conn
+    FROM pg_catalog.pg_stat_activity
+    WHERE query NOT LIKE 'autovacuum: %%'
+    UNION ALL
+    SELECT 'r', COUNT(1) 
+    FROM pg_catalog.pg_stat_replication
+) as s;
+""",
+    V91: """
+SELECT
+    SUM(s.conn) as used,
+    current_setting('max_connections')::int - current_setting('superuser_reserved_connections')::int
+    - SUM(s.conn) AS available
+FROM (
+    SELECT 's' as type, COUNT(1) as conn
+    FROM pg_catalog.pg_stat_activity
+    WHERE current_query NOT LIKE 'autovacuum: %%'
+    UNION ALL
+    SELECT 'r', COUNT(1) 
+    FROM pg_catalog.pg_stat_replication
+) as s;
+""",
+    V82: """
+SELECT
+    COUNT(1) as used,
+    current_setting('max_connections')::int - current_setting('superuser_reserved_connections')::int
+    - COUNT(1) AS available
+FROM pg_catalog.pg_stat_activity
+WHERE current_query NOT LIKE 'autovacuum: %%';
+""",
+    V72: """
+SELECT
+    COUNT(1) as used,
+    current_setting('max_connections')::int - current_setting('superuser_reserved_connections')::int
+    - COUNT(1) AS available
+FROM pg_catalog.pg_stat_activity s
+JOIN pg_catalog.pg_database d ON d.oid = s.datid
+WHERE d.datallowconn;
+""",
+}
+
+QUERY_TABLE_STATS = {
+    DEFAULT: """
+SELECT
+    ((sum(relpages) * 8) * 1024) AS table_size,
+    count(1)                     AS table_count
+FROM pg_class
+WHERE relkind IN ('r', 't');
+""",
+}
+
+QUERY_INDEX_STATS = {
+    DEFAULT: """
+SELECT
+    ((sum(relpages) * 8) * 1024) AS index_size,
+    count(1)                     AS index_count
+FROM pg_class
+WHERE relkind = 'i';
+""",
+}
+
+QUERY_DATABASE = {
+    DEFAULT: """
+SELECT
+    datname AS database_name,
+    numbackends AS connections,
+    xact_commit AS xact_commit,
+    xact_rollback AS xact_rollback,
+    blks_read AS blks_read,
+    blks_hit AS blks_hit,
+    tup_returned AS tup_returned,
+    tup_fetched AS tup_fetched,
+    tup_inserted AS tup_inserted,
+    tup_updated AS tup_updated,
+    tup_deleted AS tup_deleted,
+    conflicts AS conflicts,
+    pg_database_size(datname) AS size,
+    temp_files AS temp_files,
+    temp_bytes AS temp_bytes
+FROM pg_stat_database
+WHERE datname IN %(databases)s ;
+""",
+}
+
+QUERY_BGWRITER = {
+    DEFAULT: """
+SELECT
+    checkpoints_timed AS checkpoint_scheduled,
+    checkpoints_req AS checkpoint_requested,
+    buffers_checkpoint * current_setting('block_size')::numeric buffers_checkpoint,
+    buffers_clean * current_setting('block_size')::numeric buffers_clean,
+    maxwritten_clean,
+    buffers_backend * current_setting('block_size')::numeric buffers_backend,
+    buffers_alloc * current_setting('block_size')::numeric buffers_alloc,
+    buffers_backend_fsync
+FROM pg_stat_bgwriter;
+""",
+}
+
+QUERY_LOCKS = {
+    DEFAULT: """
+SELECT
+    pg_database.datname as database_name,
+    mode,
+    count(mode) AS locks_count
+FROM pg_locks
+INNER JOIN pg_database
+    ON pg_database.oid = pg_locks.database
+GROUP BY datname, mode
+ORDER BY datname, mode;
+""",
+}
+
+QUERY_DATABASES = {
+    DEFAULT: """
+SELECT
+    datname
+FROM pg_stat_database
+WHERE
+    has_database_privilege(
+      (SELECT current_user), datname, 'connect')
+    AND NOT datname ~* '^template\d';
+""",
+}
+
+QUERY_STANDBY = {
+    DEFAULT: """
+SELECT
+    application_name
+FROM pg_stat_replication
+WHERE application_name IS NOT NULL
+GROUP BY application_name;
+""",
+}
+
+QUERY_REPLICATION_SLOT = {
+    DEFAULT: """
+SELECT slot_name
+FROM pg_replication_slots;
+"""
+}
+
+QUERY_STANDBY_DELTA = {
+    DEFAULT: """
+SELECT
+    application_name,
+    pg_wal_lsn_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_wal_receive_lsn()
+        ELSE pg_current_wal_lsn()
+      END,
+    sent_lsn) AS sent_delta,
+    pg_wal_lsn_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_wal_receive_lsn()
+        ELSE pg_current_wal_lsn()
+      END,
+    write_lsn) AS write_delta,
+    pg_wal_lsn_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_wal_receive_lsn()
+        ELSE pg_current_wal_lsn()
+      END,
+    flush_lsn) AS flush_delta,
+    pg_wal_lsn_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_wal_receive_lsn()
+        ELSE pg_current_wal_lsn()
+      END,
+    replay_lsn) AS replay_delta
+FROM pg_stat_replication
+WHERE application_name IS NOT NULL;
+""",
+    V96: """
+SELECT
+    application_name,
+    pg_xlog_location_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_xlog_receive_location()
+        ELSE pg_current_xlog_location()
+      END,
+    sent_location) AS sent_delta,
+    pg_xlog_location_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_xlog_receive_location()
+        ELSE pg_current_xlog_location()
+      END,
+    write_location) AS write_delta,
+    pg_xlog_location_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_xlog_receive_location()
+        ELSE pg_current_xlog_location()
+      END,
+    flush_location) AS flush_delta,
+    pg_xlog_location_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_xlog_receive_location()
+        ELSE pg_current_xlog_location()
+      END,
+    replay_location) AS replay_delta
+FROM pg_stat_replication
+WHERE application_name IS NOT NULL;
+""",
+}
+
+QUERY_REPSLOT_FILES = {
+    DEFAULT: """
+WITH wal_size AS (
+  SELECT
+    setting::int AS val
+  FROM pg_settings
+  WHERE name = 'wal_segment_size'
+  )
+SELECT
+    slot_name,
+    slot_type,
+    replslot_wal_keep,
+    count(slot_file) AS replslot_files
+FROM
+    (SELECT
+        slot.slot_name,
+        CASE
+            WHEN slot_file <> 'state' THEN 1
+        END AS slot_file ,
+        slot_type,
+        COALESCE (
+          floor(
+            (pg_wal_lsn_diff(pg_current_wal_lsn (),slot.restart_lsn)
+             - (pg_walfile_name_offset (restart_lsn)).file_offset) / (s.val)
+          ),0) AS replslot_wal_keep
+    FROM pg_replication_slots slot
+    LEFT JOIN (
+        SELECT
+            slot2.slot_name,
+            pg_ls_dir('pg_replslot/' || slot2.slot_name) AS slot_file
+        FROM pg_replication_slots slot2
+        ) files (slot_name, slot_file)
+        ON slot.slot_name = files.slot_name
+    CROSS JOIN wal_size s
+    ) AS d
+GROUP BY
+    slot_name,
+    slot_type,
+    replslot_wal_keep;
+""",
+    V10: """
+WITH wal_size AS (
+  SELECT
+    current_setting('wal_block_size')::INT * setting::INT AS val
+  FROM pg_settings
+  WHERE name = 'wal_segment_size'
+  )
+SELECT
+    slot_name,
+    slot_type,
+    replslot_wal_keep,
+    count(slot_file) AS replslot_files
+FROM
+    (SELECT
+        slot.slot_name,
+        CASE
+            WHEN slot_file <> 'state' THEN 1
+        END AS slot_file ,
+        slot_type,
+        COALESCE (
+          floor(
+            (pg_wal_lsn_diff(pg_current_wal_lsn (),slot.restart_lsn)
+             - (pg_walfile_name_offset (restart_lsn)).file_offset) / (s.val)
+          ),0) AS replslot_wal_keep
+    FROM pg_replication_slots slot
+    LEFT JOIN (
+        SELECT
+            slot2.slot_name,
+            pg_ls_dir('pg_replslot/' || slot2.slot_name) AS slot_file
+        FROM pg_replication_slots slot2
+        ) files (slot_name, slot_file)
+        ON slot.slot_name = files.slot_name
+    CROSS JOIN wal_size s
+    ) AS d
+GROUP BY
+    slot_name,
+    slot_type,
+    replslot_wal_keep;
+""",
+}
+
+QUERY_SUPERUSER = {
+    DEFAULT: """
+SELECT current_setting('is_superuser') = 'on' AS is_superuser;
+""",
+}
+
+QUERY_SHOW_VERSION = {
+    DEFAULT: """
+SHOW server_version_num;
+""",
+}
+
+QUERY_AUTOVACUUM = {
+    DEFAULT: """
+SELECT
+    count(*) FILTER (WHERE query LIKE 'autovacuum: ANALYZE%%') AS analyze,
+    count(*) FILTER (WHERE query LIKE 'autovacuum: VACUUM ANALYZE%%') AS vacuum_analyze,
+    count(*) FILTER (WHERE query LIKE 'autovacuum: VACUUM%%'
+                       AND query NOT LIKE 'autovacuum: VACUUM ANALYZE%%'
+                       AND query NOT LIKE '%%to prevent wraparound%%') AS vacuum,
+    count(*) FILTER (WHERE query LIKE '%%to prevent wraparound%%') AS vacuum_freeze,
+    count(*) FILTER (WHERE query LIKE 'autovacuum: BRIN summarize%%') AS brin_summarize
+FROM pg_stat_activity
+WHERE query NOT LIKE '%%pg_stat_activity%%';
+""",
+}
+
+QUERY_DIFF_LSN = {
+    DEFAULT: """
+SELECT
+    pg_wal_lsn_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_wal_receive_lsn()
+        ELSE pg_current_wal_lsn()
+      END,
+    '0/0') as wal_writes ;
+""",
+    V96: """
+SELECT
+    pg_xlog_location_diff(
+      CASE pg_is_in_recovery()
+        WHEN true THEN pg_last_xlog_receive_location()
+        ELSE pg_current_xlog_location()
+      END,
+    '0/0') as wal_writes ;
+""",
+}
+
+def query_factory(name, version=NO_VERSION):
+    if name == QUERY_NAME_BACKENDS:
+        return QUERY_BACKEND[DEFAULT]
+    elif name == QUERY_NAME_BACKEND_USAGE:
+        if version < 80200:
+            return QUERY_BACKEND_USAGE[V72]
+        if version < 90100:
+            return QUERY_BACKEND_USAGE[V82]
+        if version < 90200:
+            return QUERY_BACKEND_USAGE[V91]
+        if version < 100000:
+            return QUERY_BACKEND_USAGE[V92]
+        elif version < 120000:
+            return QUERY_BACKEND_USAGE[V10]
+        return QUERY_BACKEND_USAGE[DEFAULT]
+    elif name == QUERY_NAME_TABLE_STATS:
+        return QUERY_TABLE_STATS[DEFAULT]
+    elif name == QUERY_NAME_INDEX_STATS:
+        return QUERY_INDEX_STATS[DEFAULT]
+    elif name == QUERY_NAME_DATABASE:
+        return QUERY_DATABASE[DEFAULT]
+    elif name == QUERY_NAME_BGWRITER:
+        return QUERY_BGWRITER[DEFAULT]
+    elif name == QUERY_NAME_LOCKS:
+        return QUERY_LOCKS[DEFAULT]
+    elif name == QUERY_NAME_DATABASES:
+        return QUERY_DATABASES[DEFAULT]
+    elif name == QUERY_NAME_STANDBY:
+        return QUERY_STANDBY[DEFAULT]
+    elif name == QUERY_NAME_REPLICATION_SLOT:
+        return QUERY_REPLICATION_SLOT[DEFAULT]
+    elif name == QUERY_NAME_IF_SUPERUSER:
+        return QUERY_SUPERUSER[DEFAULT]
+    elif name == QUERY_NAME_SERVER_VERSION:
+        return QUERY_SHOW_VERSION[DEFAULT]
+    elif name == QUERY_NAME_AUTOVACUUM:
+        return QUERY_AUTOVACUUM[DEFAULT]
+    elif name == QUERY_NAME_WAL:
+        if version < 100000:
+            return QUERY_WAL[V96]
+        return QUERY_WAL[DEFAULT]
+    elif name == QUERY_NAME_ARCHIVE:
+        if version < 100000:
+            return QUERY_ARCHIVE[V96]
+        return QUERY_ARCHIVE[DEFAULT]
+    elif name == QUERY_NAME_STANDBY_DELTA:
+        if version < 100000:
+            return QUERY_STANDBY_DELTA[V96]
+        return QUERY_STANDBY_DELTA[DEFAULT]
+    elif name == QUERY_NAME_REPSLOT_FILES:
+        if version < 110000:
+            return QUERY_REPSLOT_FILES[V10]
+        return QUERY_REPSLOT_FILES[DEFAULT]
+    elif name == QUERY_NAME_DIFF_LSN:
+        if version < 100000:
+            return QUERY_DIFF_LSN[V96]
+        return QUERY_DIFF_LSN[DEFAULT]
+
+    raise ValueError('unknown query')
+
+
+ORDER = [
+    'db_stat_temp_files',
+    'db_stat_temp_bytes',
+    'db_stat_blks',
+    'db_stat_tuple_returned',
+    'db_stat_tuple_write',
+    'db_stat_transactions',
+    'db_stat_connections',
+    'database_size',
+    'backend_process',
+    'backend_usage',
+    'index_count',
+    'index_size',
+    'table_count',
+    'table_size',
+    'wal',
+    'wal_writes',
+    'archive_wal',
+    'checkpointer',
+    'stat_bgwriter_alloc',
+    'stat_bgwriter_checkpoint',
+    'stat_bgwriter_backend',
+    'stat_bgwriter_backend_fsync',
+    'stat_bgwriter_bgwriter',
+    'stat_bgwriter_maxwritten',
+    'replication_slot',
+    'standby_delta',
+    'autovacuum'
+]
+
+CHARTS = {
+    'db_stat_transactions': {
+        'options': [None, 'Transactions on db', 'transactions/s', 'db statistics', 'postgres.db_stat_transactions',
+                    'line'],
+        'lines': [
+            ['xact_commit', 'committed', 'incremental'],
+            ['xact_rollback', 'rolled back', 'incremental']
+        ]
+    },
+    'db_stat_connections': {
+        'options': [None, 'Current connections to db', 'count', 'db statistics', 'postgres.db_stat_connections',
+                    'line'],
+        'lines': [
+            ['connections', 'connections', 'absolute']
+        ]
+    },
+    'db_stat_blks': {
+        'options': [None, 'Disk blocks reads from db', 'reads/s', 'db statistics', 'postgres.db_stat_blks', 'line'],
+        'lines': [
+            ['blks_read', 'disk', 'incremental'],
+            ['blks_hit', 'cache', 'incremental']
+        ]
+    },
+    'db_stat_tuple_returned': {
+        'options': [None, 'Tuples returned from db', 'tuples/s', 'db statistics', 'postgres.db_stat_tuple_returned',
+                    'line'],
+        'lines': [
+            ['tup_returned', 'sequential', 'incremental'],
+            ['tup_fetched', 'bitmap', 'incremental']
+        ]
+    },
+    'db_stat_tuple_write': {
+        'options': [None, 'Tuples written to db', 'writes/s', 'db statistics', 'postgres.db_stat_tuple_write', 'line'],
+        'lines': [
+            ['tup_inserted', 'inserted', 'incremental'],
+            ['tup_updated', 'updated', 'incremental'],
+            ['tup_deleted', 'deleted', 'incremental'],
+            ['conflicts', 'conflicts', 'incremental']
+        ]
+    },
+    'db_stat_temp_bytes': {
+        'options': [None, 'Temp files written to disk', 'KiB/s', 'db statistics', 'postgres.db_stat_temp_bytes',
+                    'line'],
+        'lines': [
+            ['temp_bytes', 'size', 'incremental', 1, 1024]
+        ]
+    },
+    'db_stat_temp_files': {
+        'options': [None, 'Temp files written to disk', 'files', 'db statistics', 'postgres.db_stat_temp_files',
+                    'line'],
+        'lines': [
+            ['temp_files', 'files', 'incremental']
+        ]
+    },
+    'database_size': {
+        'options': [None, 'Database size', 'MiB', 'database size', 'postgres.db_size', 'stacked'],
+        'lines': [
+        ]
+    },
+    'backend_process': {
+        'options': [None, 'Current Backend Processes', 'processes', 'backend processes', 'postgres.backend_process',
+                    'line'],
+        'lines': [
+            ['backends_active', 'active', 'absolute'],
+            ['backends_idle', 'idle', 'absolute']
+        ]
+    },
+    'backend_usage': {
+        'options': [None, '% of Connections in use', 'percentage', 'backend processes', 'postgres.backend_usage', 'stacked'],
+        'lines': [
+            ['available', 'available', 'percentage-of-absolute-row'],
+            ['used', 'used', 'percentage-of-absolute-row']
+        ]
+    },
+    'index_count': {
+        'options': [None, 'Total indexes', 'index', 'indexes', 'postgres.index_count', 'line'],
+        'lines': [
+            ['index_count', 'total', 'absolute']
+        ]
+    },
+    'index_size': {
+        'options': [None, 'Indexes size', 'MiB', 'indexes', 'postgres.index_size', 'line'],
+        'lines': [
+            ['index_size', 'size', 'absolute', 1, 1024 * 1024]
+        ]
+    },
+    'table_count': {
+        'options': [None, 'Total Tables', 'tables', 'tables', 'postgres.table_count', 'line'],
+        'lines': [
+            ['table_count', 'total', 'absolute']
+        ]
+    },
+    'table_size': {
+        'options': [None, 'Tables size', 'MiB', 'tables', 'postgres.table_size', 'line'],
+        'lines': [
+            ['table_size', 'size', 'absolute', 1, 1024 * 1024]
+        ]
+    },
+    'wal': {
+        'options': [None, 'Write-Ahead Logs', 'files', 'wal', 'postgres.wal', 'line'],
+        'lines': [
+            ['written_wal', 'written', 'absolute'],
+            ['recycled_wal', 'recycled', 'absolute'],
+            ['total_wal', 'total', 'absolute']
+        ]
+    },
+    'wal_writes': {
+        'options': [None, 'Write-Ahead Logs', 'KiB/s', 'wal_writes', 'postgres.wal_writes', 'line'],
+        'lines': [
+            ['wal_writes', 'writes', 'incremental', 1, 1024]
+        ]
+    },
+    'archive_wal': {
+        'options': [None, 'Archive Write-Ahead Logs', 'files/s', 'archive wal', 'postgres.archive_wal', 'line'],
+        'lines': [
+            ['file_count', 'total', 'incremental'],
+            ['ready_count', 'ready', 'incremental'],
+            ['done_count', 'done', 'incremental']
+        ]
+    },
+    'checkpointer': {
+        'options': [None, 'Checkpoints', 'writes', 'checkpointer', 'postgres.checkpointer', 'line'],
+        'lines': [
+            ['checkpoint_scheduled', 'scheduled', 'incremental'],
+            ['checkpoint_requested', 'requested', 'incremental']
+        ]
+    },
+    'stat_bgwriter_alloc': {
+        'options': [None, 'Buffers allocated', 'KiB/s', 'bgwriter', 'postgres.stat_bgwriter_alloc', 'line'],
+        'lines': [
+            ['buffers_alloc', 'alloc', 'incremental', 1, 1024]
+        ]
+    },
+    'stat_bgwriter_checkpoint': {
+        'options': [None, 'Buffers written during checkpoints', 'KiB/s', 'bgwriter',
+                    'postgres.stat_bgwriter_checkpoint', 'line'],
+        'lines': [
+            ['buffers_checkpoint', 'checkpoint', 'incremental', 1, 1024]
+        ]
+    },
+    'stat_bgwriter_backend': {
+        'options': [None, 'Buffers written directly by a backend', 'KiB/s', 'bgwriter',
+                    'postgres.stat_bgwriter_backend', 'line'],
+        'lines': [
+            ['buffers_backend', 'backend', 'incremental', 1, 1024]
+        ]
+    },
+    'stat_bgwriter_backend_fsync': {
+        'options': [None, 'Fsync by backend', 'times', 'bgwriter', 'postgres.stat_bgwriter_backend_fsync', 'line'],
+        'lines': [
+            ['buffers_backend_fsync', 'backend fsync', 'incremental']
+        ]
+    },
+    'stat_bgwriter_bgwriter': {
+        'options': [None, 'Buffers written by the background writer', 'KiB/s', 'bgwriter',
+                    'postgres.bgwriter_bgwriter', 'line'],
+        'lines': [
+            ['buffers_clean', 'clean', 'incremental', 1, 1024]
+        ]
+    },
+    'stat_bgwriter_maxwritten': {
+        'options': [None, 'Too many buffers written', 'times', 'bgwriter', 'postgres.stat_bgwriter_maxwritten',
+                    'line'],
+        'lines': [
+            ['maxwritten_clean', 'maxwritten', 'incremental']
+        ]
+    },
+    'autovacuum': {
+        'options': [None, 'Autovacuum workers', 'workers', 'autovacuum', 'postgres.autovacuum', 'line'],
+        'lines': [
+            ['analyze', 'analyze', 'absolute'],
+            ['vacuum', 'vacuum', 'absolute'],
+            ['vacuum_analyze', 'vacuum analyze', 'absolute'],
+            ['vacuum_freeze', 'vacuum freeze', 'absolute'],
+            ['brin_summarize', 'brin summarize', 'absolute']
+        ]
+    },
+    'standby_delta': {
+        'options': [None, 'Standby delta', 'KiB', 'replication delta', 'postgres.standby_delta', 'line'],
+        'lines': [
+            ['sent_delta', 'sent delta', 'absolute', 1, 1024],
+            ['write_delta', 'write delta', 'absolute', 1, 1024],
+            ['flush_delta', 'flush delta', 'absolute', 1, 1024],
+            ['replay_delta', 'replay delta', 'absolute', 1, 1024]
+        ]
+    },
+    'replication_slot': {
+        'options': [None, 'Replication slot files', 'files', 'replication slot', 'postgres.replication_slot', 'line'],
+        'lines': [
+            ['replslot_wal_keep', 'wal keeped', 'absolute'],
+            ['replslot_files', 'pg_replslot files', 'absolute']
+        ]
+    }
+}
+
+
+class Service(SimpleService):
+    def __init__(self, configuration=None, name=None):
+        SimpleService.__init__(self, configuration=configuration, name=name)
+        self.order = list(ORDER)
+        self.definitions = deepcopy(CHARTS)
+        self.do_table_stats = configuration.pop('table_stats', False)
+        self.do_index_stats = configuration.pop('index_stats', False)
+        self.databases_to_poll = configuration.pop('database_poll', None)
+        self.configuration = configuration
+        self.conn = None
+        self.conn_params = dict()
+        self.server_version = None
+        self.is_superuser = False
+        self.alive = False
+        self.databases = list()
+        self.secondaries = list()
+        self.replication_slots = list()
+        self.queries = dict()
+        self.data = dict()
+
+    def reconnect(self):
+        return self.connect()
+
+    def build_conn_params(self):
+        conf = self.configuration
+
+        # connection URIs: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING
+        if conf.get(CONN_PARAM_DSN):
+            return {'dsn': conf[CONN_PARAM_DSN]}
+
+        params = {
+            CONN_PARAM_HOST: conf.get(CONN_PARAM_HOST),
+            CONN_PARAM_PORT: conf.get(CONN_PARAM_PORT, DEFAULT_PORT),
+            CONN_PARAM_DATABASE: conf.get(CONN_PARAM_DATABASE),
+            CONN_PARAM_USER: conf.get(CONN_PARAM_USER, DEFAULT_USER),
+            CONN_PARAM_PASSWORD: conf.get(CONN_PARAM_PASSWORD),
+            CONN_PARAM_CONN_TIMEOUT: conf.get(CONN_PARAM_CONN_TIMEOUT, DEFAULT_CONNECT_TIMEOUT),
+            'options': '-c statement_timeout={0}'.format(
+                conf.get(CONN_PARAM_STATEMENT_TIMEOUT, DEFAULT_STATEMENT_TIMEOUT)),
+        }
+
+        # https://www.postgresql.org/docs/current/libpq-ssl.html
+        ssl_params = dict(
+            (k, v) for k, v in {
+                CONN_PARAM_SSL_MODE: conf.get(CONN_PARAM_SSL_MODE),
+                CONN_PARAM_SSL_ROOT_CERT: conf.get(CONN_PARAM_SSL_ROOT_CERT),
+                CONN_PARAM_SSL_CRL: conf.get(CONN_PARAM_SSL_CRL),
+                CONN_PARAM_SSL_CERT: conf.get(CONN_PARAM_SSL_CERT),
+                CONN_PARAM_SSL_KEY: conf.get(CONN_PARAM_SSL_KEY),
+            }.items() if v)
+
+        if CONN_PARAM_SSL_MODE not in ssl_params and len(ssl_params) > 0:
+            raise ValueError("mandatory 'sslmode' param is missing, please set")
+
+        params.update(ssl_params)
+
+        return params
+
+    def connect(self):
+        if self.conn:
+            self.conn.close()
+            self.conn = None
+
+        try:
+            self.conn = psycopg2.connect(**self.conn_params)
+            self.conn.set_isolation_level(extensions.ISOLATION_LEVEL_AUTOCOMMIT)
+            self.conn.set_session(readonly=True)
+        except OperationalError as error:
+            self.error(error)
+            self.alive = False
+        else:
+            self.alive = True
+
+        return self.alive
+
+    def check(self):
+        if not PSYCOPG2:
+            self.error("'python-psycopg2' package is needed to use postgres module")
+            return False
+
+        try:
+            self.conn_params = self.build_conn_params()
+        except ValueError as error:
+            self.error('error on creating connection params : {0}', error)
+            return False
+
+        if not self.connect():
+            self.error('failed to connect to {0}'.format(hide_password(self.conn_params)))
+            return False
+
+        try:
+            self.check_queries()
+        except Exception as error:
+            self.error(error)
+            return False
+
+        self.populate_queries()
+        self.create_dynamic_charts()
+
+        return True
+
+    def get_data(self):
+        if not self.alive and not self.reconnect():
+            return None
+
+        self.data = dict()
+        try:
+            cursor = self.conn.cursor(cursor_factory=DictCursor)
+
+            self.data.update(zero_lock_types(self.databases))
+
+            for query, metrics in self.queries.items():
+                self.query_stats(cursor, query, metrics)
+
+        except OperationalError:
+            self.alive = False
+            return None
+
+        cursor.close()
+
+        return self.data
+
+    def query_stats(self, cursor, query, metrics):
+        cursor.execute(query, dict(databases=tuple(self.databases)))
+
+        for row in cursor:
+            for metric in metrics:
+                #  databases
+                if 'database_name' in row:
+                    dimension_id = '_'.join([row['database_name'], metric])
+                #  secondaries
+                elif 'application_name' in row:
+                    dimension_id = '_'.join([row['application_name'], metric])
+                # replication slots
+                elif 'slot_name' in row:
+                    dimension_id = '_'.join([row['slot_name'], metric])
+                #  other
+                else:
+                    dimension_id = metric
+
+                if metric in row:
+                    if row[metric] is not None:
+                        self.data[dimension_id] = int(row[metric])
+                elif 'locks_count' in row:
+                    if metric == row['mode']:
+                        self.data[dimension_id] = row['locks_count']
+
+    def check_queries(self):
+        cursor = self.conn.cursor()
+
+        self.server_version = detect_server_version(cursor, query_factory(QUERY_NAME_SERVER_VERSION))
+        self.debug('server version: {0}'.format(self.server_version))
+
+        self.is_superuser = check_if_superuser(cursor, query_factory(QUERY_NAME_IF_SUPERUSER))
+        self.debug('superuser: {0}'.format(self.is_superuser))
+
+        self.databases = discover(cursor, query_factory(QUERY_NAME_DATABASES))
+        self.debug('discovered databases {0}'.format(self.databases))
+        if self.databases_to_poll:
+            to_poll = self.databases_to_poll.split()
+            self.databases = [db for db in self.databases if db in to_poll] or self.databases
+
+        self.secondaries = discover(cursor, query_factory(QUERY_NAME_STANDBY))
+        self.debug('discovered secondaries: {0}'.format(self.secondaries))
+
+        if self.server_version >= 94000:
+            self.replication_slots = discover(cursor, query_factory(QUERY_NAME_REPLICATION_SLOT))
+            self.debug('discovered replication slots: {0}'.format(self.replication_slots))
+
+        cursor.close()
+
+    def populate_queries(self):
+        self.queries[query_factory(QUERY_NAME_DATABASE)] = METRICS[QUERY_NAME_DATABASE]
+        self.queries[query_factory(QUERY_NAME_BACKENDS)] = METRICS[QUERY_NAME_BACKENDS]
+        self.queries[query_factory(QUERY_NAME_BACKEND_USAGE, self.server_version)] = METRICS[QUERY_NAME_BACKEND_USAGE]
+        self.queries[query_factory(QUERY_NAME_LOCKS)] = METRICS[QUERY_NAME_LOCKS]
+        self.queries[query_factory(QUERY_NAME_BGWRITER)] = METRICS[QUERY_NAME_BGWRITER]
+        self.queries[query_factory(QUERY_NAME_DIFF_LSN, self.server_version)] = METRICS[QUERY_NAME_WAL_WRITES]
+        self.queries[query_factory(QUERY_NAME_STANDBY_DELTA, self.server_version)] = METRICS[QUERY_NAME_STANDBY_DELTA]
+
+        if self.do_index_stats:
+            self.queries[query_factory(QUERY_NAME_INDEX_STATS)] = METRICS[QUERY_NAME_INDEX_STATS]
+        if self.do_table_stats:
+            self.queries[query_factory(QUERY_NAME_TABLE_STATS)] = METRICS[QUERY_NAME_TABLE_STATS]
+
+        if self.is_superuser:
+            self.queries[query_factory(QUERY_NAME_ARCHIVE, self.server_version)] = METRICS[QUERY_NAME_ARCHIVE]
+
+            if self.server_version >= 90400:
+                self.queries[query_factory(QUERY_NAME_WAL, self.server_version)] = METRICS[QUERY_NAME_WAL]
+
+            if self.server_version >= 100000:
+                v = METRICS[QUERY_NAME_REPSLOT_FILES]
+                self.queries[query_factory(QUERY_NAME_REPSLOT_FILES, self.server_version)] = v
+
+        if self.server_version >= 90400:
+            self.queries[query_factory(QUERY_NAME_AUTOVACUUM)] = METRICS[QUERY_NAME_AUTOVACUUM]
+
+    def create_dynamic_charts(self):
+        for database_name in self.databases[::-1]:
+            dim = [
+                database_name + '_size',
+                database_name,
+                'absolute',
+                1,
+                1024 * 1024,
+            ]
+            self.definitions['database_size']['lines'].append(dim)
+            for chart_name in [name for name in self.order if name.startswith('db_stat')]:
+                add_database_stat_chart(
+                    order=self.order,
+                    definitions=self.definitions,
+                    name=chart_name,
+                    database_name=database_name,
+                )
+            add_database_lock_chart(
+                order=self.order,
+                definitions=self.definitions,
+                database_name=database_name,
+            )
+
+        for application_name in self.secondaries[::-1]:
+            add_replication_delta_chart(
+                order=self.order,
+                definitions=self.definitions,
+                name='standby_delta',
+                application_name=application_name,
+            )
+
+        for slot_name in self.replication_slots[::-1]:
+            add_replication_slot_chart(
+                order=self.order,
+                definitions=self.definitions,
+                name='replication_slot',
+                slot_name=slot_name,
+            )
+
+
+def discover(cursor, query):
+    cursor.execute(query)
+    result = list()
+    for v in [value[0] for value in cursor]:
+        if v not in result:
+            result.append(v)
+    return result
+
+
+def check_if_superuser(cursor, query):
+    cursor.execute(query)
+    return cursor.fetchone()[0]
+
+
+def detect_server_version(cursor, query):
+    cursor.execute(query)
+    return int(cursor.fetchone()[0])
+
+
+def zero_lock_types(databases):
+    result = dict()
+    for database in databases:
+        for lock_type in METRICS['LOCKS']:
+            key = '_'.join([database, lock_type])
+            result[key] = 0
+
+    return result
+
+
+def hide_password(config):
+    return dict((k, v if k != 'password' or not v else '*****') for k, v in config.items())
+
+
+def add_database_lock_chart(order, definitions, database_name):
+    def create_lines(database):
+        result = list()
+        for lock_type in METRICS['LOCKS']:
+            dimension_id = '_'.join([database, lock_type])
+            result.append([dimension_id, lock_type, 'absolute'])
+        return result
+
+    chart_name = database_name + '_locks'
+    order.insert(-1, chart_name)
+    definitions[chart_name] = {
+        'options':
+            [None, 'Locks on db: ' + database_name, 'locks', 'db ' + database_name, 'postgres.db_locks', 'line'],
+        'lines': create_lines(database_name)
+    }
+
+
+def add_database_stat_chart(order, definitions, name, database_name):
+    def create_lines(database, lines):
+        result = list()
+        for line in lines:
+            new_line = ['_'.join([database, line[0]])] + line[1:]
+            result.append(new_line)
+        return result
+
+    chart_template = CHARTS[name]
+    chart_name = '_'.join([database_name, name])
+    order.insert(0, chart_name)
+    name, title, units, _, context, chart_type = chart_template['options']
+    definitions[chart_name] = {
+        'options': [name, title + ': ' + database_name, units, 'db ' + database_name, context, chart_type],
+        'lines': create_lines(database_name, chart_template['lines'])}
+
+
+def add_replication_delta_chart(order, definitions, name, application_name):
+    def create_lines(standby, lines):
+        result = list()
+        for line in lines:
+            new_line = ['_'.join([standby, line[0]])] + line[1:]
+            result.append(new_line)
+        return result
+
+    chart_template = CHARTS[name]
+    chart_name = '_'.join([application_name, name])
+    position = order.index('database_size')
+    order.insert(position, chart_name)
+    name, title, units, _, context, chart_type = chart_template['options']
+    definitions[chart_name] = {
+        'options': [name, title + ': ' + application_name, units, 'replication delta', context, chart_type],
+        'lines': create_lines(application_name, chart_template['lines'])}
+
+
+def add_replication_slot_chart(order, definitions, name, slot_name):
+    def create_lines(slot, lines):
+        result = list()
+        for line in lines:
+            new_line = ['_'.join([slot, line[0]])] + line[1:]
+            result.append(new_line)
+        return result
+
+    chart_template = CHARTS[name]
+    chart_name = '_'.join([slot_name, name])
+    position = order.index('database_size')
+    order.insert(position, chart_name)
+    name, title, units, _, context, chart_type = chart_template['options']
+    definitions[chart_name] = {
+        'options': [name, title + ': ' + slot_name, units, 'replication slot files', context, chart_type],
+        'lines': create_lines(slot_name, chart_template['lines'])}
diff --git a/collectors/python.d.plugin/postgres/postgres.conf b/collectors/python.d.plugin/postgres/postgres.conf
new file mode 100644
index 0000000..1970a7a
--- /dev/null
+++ b/collectors/python.d.plugin/postgres/postgres.conf
@@ -0,0 +1,141 @@
+# netdata python.d.plugin configuration for postgresql
+#
+# This file is in YaML format. Generally the format is:
+#
+# name: value
+#
+# There are 2 sections:
+#  - global variables
+#  - one or more JOBS
+#
+# JOBS allow you to collect values from multiple sources.
+# Each source will have its own set of charts.
+#
+# JOB parameters have to be indented (using spaces only, example below).
+
+# ----------------------------------------------------------------------
+# Global Variables
+# These variables set the defaults for all JOBs, however each JOB
+# may define its own, overriding the defaults.
+
+# update_every sets the default data collection frequency.
+# If unset, the python.d.plugin default is used.
+# update_every: 1
+
+# priority controls the order of charts at the netdata dashboard.
+# Lower numbers move the charts towards the top of the page.
+# If unset, the default for python.d.plugin is used.
+# priority: 60000
+
+# penalty indicates whether to apply penalty to update_every in case of failures.
+# Penalty will increase every 5 failed updates in a row. Maximum penalty is 10 minutes.
+# penalty: yes
+
+# autodetection_retry sets the job re-check interval in seconds.
+# The job is not deleted if check fails.
+# Attempts to start the job are made once every autodetection_retry.
+# This feature is disabled by default.
+# autodetection_retry: 0
+
+# ----------------------------------------------------------------------
+# JOBS (data collection sources)
+#
+# The default JOBS share the same *name*. JOBS with the same name
+# are mutually exclusive. Only one of them will be allowed running at
+# any time. This allows autodetection to try several alternatives and
+# pick the one that works.
+#
+# Any number of jobs is supported.
+#
+# All python.d.plugin JOBS (for all its modules) support a set of
+# predefined parameters. These are:
+#
+# job_name:
+#     name: myname            # the JOB's name as it will appear at the
+#                             # dashboard (by default is the job_name)
+#                             # JOBs sharing a name are mutually exclusive
+#     update_every: 1         # the JOB's data collection frequency
+#     priority: 60000         # the JOB's order on the dashboard
+#     penalty: yes            # the JOB's penalty
+#     autodetection_retry: 0  # the JOB's re-check interval in seconds
+#
+# A single connection is required in order to pull statistics.
+#
+# Connections can be configured with the following options:
+#
+#     dsn                 : 'connection URI'  # see https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING
+#
+#     OR
+#
+#     database            : 'example_db_name'
+#     user                : 'example_user'
+#     password            : 'example_pass'
+#     host                : 'localhost'
+#     port                : 5432
+#     connect_timeout     : 2                  # in seconds, default is 2
+#     statement_timeout   : 2000               # in ms, default is 2000
+#     sslmode             : mode               # one of [disable, allow, prefer, require, verify-ca, verify-full]
+#     sslrootcert         : path/to/rootcert   # the location of the root certificate file
+#     sslcrl              : path/to/crl        # the location of the CRL file
+#     sslcert             : path/to/cert       # the location of the client certificate file
+#     sslkey              : path/to/key        # the location of the client key file
+#
+# SSL connection parameters description: https://www.postgresql.org/docs/current/libpq-ssl.html
+# 
+# Additionally, the following options allow selective disabling of charts
+#
+#     table_stats : false
+#     index_stats : false
+#     database_poll : 'dbase_name1 dbase_name2' # poll only specified databases (all other will be excluded from charts)
+#
+# Postgres permissions are configured at its pg_hba.conf file. You can
+# "trust" local clients to allow netdata to connect, or you can create
+# a postgres user for netdata and add its password below to allow
+# netdata connect.
+#
+# Please note that when running Postgres from inside the container, 
+# the client (Netdata) is not considered local, unless it runs from inside
+# the same container. 
+#
+# Postgres supported versions are : 
+# - 9.3 (without autovacuum)
+# - 9.4
+# - 9.5
+# - 9.6
+# - 10
+#
+# Superuser access is needed for theses charts:
+#   Write-Ahead Logs
+#   Archive Write-Ahead Logs
+#
+# Autovacuum charts is allowed since Postgres 9.4
+# ----------------------------------------------------------------------
+
+socket:
+    name     : 'local'
+    user     : 'postgres'
+    database : 'postgres'
+
+tcp:
+    name     : 'local'
+    database : 'postgres'
+    user     : 'postgres'
+    password : 'postgres'
+    host     : 'localhost'
+    port     : 5432
+
+tcpipv4:
+    name     : 'local'
+    database : 'postgres'
+    user     : 'postgres'
+    password : 'postgres'
+    host     : '127.0.0.1'
+    port     : 5432
+
+tcpipv6:
+    name     : 'local'
+    database : 'postgres'
+    user     : 'postgres'
+    password : 'postgres'
+    host     : '::1'
+    port     : 5432