Add the postgresql_extensible plugin

plugins/inputs/all/all.go

@@ -33,6 +33,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/phpfpm"
 	_ "github.com/influxdata/telegraf/plugins/inputs/ping"
 	_ "github.com/influxdata/telegraf/plugins/inputs/postgresql"
+	_ "github.com/influxdata/telegraf/plugins/inputs/postgresql_extensible"
 	_ "github.com/influxdata/telegraf/plugins/inputs/powerdns"
 	_ "github.com/influxdata/telegraf/plugins/inputs/procstat"
 	_ "github.com/influxdata/telegraf/plugins/inputs/prometheus"

plugins/inputs/postgresql_extensible/README.md

@@ -0,0 +1,231 @@
+# PostgreSQL plugin
+
+This postgresql plugin provides metrics for your postgres database. It has been
+designed to parse ithe sql queries in the plugin section of your telegraf.conf.
+
+For now only two queries are specified and it's up to you to add more; some per
+query parameters have been added :
+
+* The SQl query itself
+* The minimum version supported (here in numeric display visible in pg_settings)
+* A boolean to define if the query have to be run against some specific
+* variables (defined in the databaes variable of the plugin section)
+* The list of the column that have to be defined has tags
+
+```
+[[inputs.postgresql_extensible]]
+  # specify address via a url matching:
+  # postgres://[pqgotest[:password]]@localhost[/dbname]?sslmode=...
+  # or a simple string:
+  #   host=localhost user=pqotest password=... sslmode=... dbname=app_production
+  #
+  # All connection parameters are optional.  #
+  # Without the dbname parameter, the driver will default to a database
+  # with the same name as the user. This dbname is just for instantiating a
+  # connection with the server and doesn't restrict the databases we are trying
+  # to grab metrics for.
+  #
+  address = "host=localhost user=postgres sslmode=disable"
+  # A list of databases to pull metrics about. If not specified, metrics for all
+  # databases are gathered.
+  # databases = ["app_production", "testing"]
+  #
+  # Define the toml config where the sql queries are stored
+  # New queries can be added, if the withdbname is set to true and there is no
+  # databases defined in the 'databases field', the sql query is ended by a 'is
+  # not null' in order to make the query succeed.
+  # Be careful that the sqlquery must contain the where clause with a part of
+  # the filtering, the plugin will add a 'IN (dbname list)' clause if the
+  # withdbname is set to true
+  # Example :
+  # The sqlquery : "SELECT * FROM pg_stat_database where datname" become
+  # "SELECT * FROM pg_stat_database where datname IN ('postgres', 'pgbench')"
+  # because the databases variable was set to ['postgres', 'pgbench' ] and the
+  # withdbname was true.
+  # Be careful that if the withdbname is set to false you d'ont have to define
+  # the where clause (aka with the dbname)
+  # the tagvalue field is used to define custom tags (separated by comas)
+  #
+  # Structure :
+  # [[inputs.postgresql_extensible.query]]
+  #   sqlquery string
+  #   version string
+  #   withdbname boolean
+  #   tagvalue string (coma separated)
+  [[inputs.postgresql_extensible.query]]
+    sqlquery="SELECT * FROM pg_stat_database where datname"
+    version=901
+    withdbname=false
+    tagvalue=""
+  [[inputs.postgresql_extensible.query]]
+    sqlquery="SELECT * FROM pg_stat_bgwriter"
+    version=901
+    withdbname=false
+    tagvalue=""
+```
+
+The system can be easily extended using homemade metrics collection tools or
+using postgreql extensions ([pg_stat_statements](http://www.postgresql.org/docs/current/static/pgstatstatements.html), [pg_proctab](https://github.com/markwkm/pg_proctab),[powa](http://dalibo.github.io/powa/)...)
+
+# Sample Queries :
+- telegraf.conf postgresql_extensible queries (assuming that you have configured
+ correctly your connection)
+```
+[[inputs.postgresql_extensible.query]]
+  sqlquery="SELECT * FROM pg_stat_database"
+  version=901
+  withdbname=false
+  tagvalue=""
+[[inputs.postgresql_extensible.query]]
+  sqlquery="SELECT * FROM pg_stat_bgwriter"
+  version=901
+  withdbname=false
+  tagvalue=""
+[[inputs.postgresql_extensible.query]]
+  sqlquery="select * from sessions"
+  version=901
+  withdbname=false
+  tagvalue="db,username,state"
+[[inputs.postgresql_extensible.query]]
+  sqlquery="select setting as max_connections from pg_settings where \
+  name='max_connections'"
+  version=801
+  withdbname=false
+  tagvalue=""
+[[inputs.postgresql_extensible.query]]
+  sqlquery="select * from pg_stat_kcache"
+  version=901
+  withdbname=false
+  tagvalue=""
+[[inputs.postgresql_extensible.query]]
+  sqlquery="select setting as shared_buffers from pg_settings where \
+  name='shared_buffers'"
+  version=801
+  withdbname=false
+  tagvalue=""
+[[inputs.postgresql_extensible.query]]
+  sqlquery="SELECT db, count( distinct blocking_pid ) AS num_blocking_sessions,\
+  count( distinct blocked_pid) AS num_blocked_sessions FROM \
+  public.blocking_procs group by db"
+  version=901
+  withdbname=false
+  tagvalue="db"
+```
+
+# Postgresql Side
+postgresql.conf :
+```
+shared_preload_libraries = 'pg_stat_statements,pg_stat_kcache'
+```
+
+Please follow the requirements to setup those extensions.
+
+In the database (can be a specific monitoring db)
+```
+create extension pg_stat_statements;
+create extension pg_stat_kcache;
+create extension pg_proctab;
+```
+(assuming that the extension is installed on the OS Layer)
+
+ - pg_stat_kcache is available on the postgresql.org yum repo
+ - pg_proctab is available at : https://github.com/markwkm/pg_proctab
+
+ ##Views
+ - Blocking sessions
+```
+CREATE OR REPLACE VIEW public.blocking_procs AS
+ SELECT a.datname AS db,
+    kl.pid AS blocking_pid,
+    ka.usename AS blocking_user,
+    ka.query AS blocking_query,
+    bl.pid AS blocked_pid,
+    a.usename AS blocked_user,
+    a.query AS blocked_query,
+    to_char(age(now(), a.query_start), 'HH24h:MIm:SSs'::text) AS age
+   FROM pg_locks bl
+     JOIN pg_stat_activity a ON bl.pid = a.pid
+     JOIN pg_locks kl ON bl.locktype = kl.locktype AND NOT bl.database IS
+     DISTINCT FROM kl.database AND NOT bl.relation IS DISTINCT FROM kl.relation
+     AND NOT bl.page IS DISTINCT FROM kl.page AND NOT bl.tuple IS DISTINCT FROM
+     kl.tuple AND NOT bl.virtualxid IS DISTINCT FROM kl.virtualxid AND NOT
+     bl.transactionid IS DISTINCT FROM kl.transactionid AND NOT bl.classid IS
+     DISTINCT FROM kl.classid AND NOT bl.objid IS DISTINCT FROM kl.objid AND
+      NOT bl.objsubid IS DISTINCT FROM kl.objsubid AND bl.pid <> kl.pid
+     JOIN pg_stat_activity ka ON kl.pid = ka.pid
+  WHERE kl.granted AND NOT bl.granted
+  ORDER BY a.query_start;
+```
+  - Sessions Statistics
+```
+CREATE OR REPLACE VIEW public.sessions AS
+ WITH proctab AS (
+         SELECT pg_proctab.pid,
+                CASE
+                    WHEN pg_proctab.state::text = 'R'::bpchar::text
+                      THEN 'running'::text
+                    WHEN pg_proctab.state::text = 'D'::bpchar::text
+                      THEN 'sleep-io'::text
+                    WHEN pg_proctab.state::text = 'S'::bpchar::text
+                      THEN 'sleep-waiting'::text
+                    WHEN pg_proctab.state::text = 'Z'::bpchar::text
+                      THEN 'zombie'::text
+                    WHEN pg_proctab.state::text = 'T'::bpchar::text
+                      THEN 'stopped'::text
+                    ELSE NULL::text
+                END AS proc_state,
+            pg_proctab.ppid,
+            pg_proctab.utime,
+            pg_proctab.stime,
+            pg_proctab.vsize,
+            pg_proctab.rss,
+            pg_proctab.processor,
+            pg_proctab.rchar,
+            pg_proctab.wchar,
+            pg_proctab.syscr,
+            pg_proctab.syscw,
+            pg_proctab.reads,
+            pg_proctab.writes,
+            pg_proctab.cwrites
+           FROM pg_proctab() pg_proctab(pid, comm, fullcomm, state, ppid, pgrp,
+             session, tty_nr, tpgid, flags, minflt, cminflt, majflt, cmajflt,
+             utime, stime, cutime, cstime, priority, nice, num_threads,
+             itrealvalue, starttime, vsize, rss, exit_signal, processor,
+             rt_priority, policy, delayacct_blkio_ticks, uid, username, rchar,
+             wchar, syscr, syscw, reads, writes, cwrites)
+        ), stat_activity AS (
+         SELECT pg_stat_activity.datname,
+            pg_stat_activity.pid,
+            pg_stat_activity.usename,
+                CASE
+                    WHEN pg_stat_activity.query IS NULL THEN 'no query'::text
+                    WHEN pg_stat_activity.query IS NOT NULL AND
+                    pg_stat_activity.state = 'idle'::text THEN 'no query'::text
+                    ELSE regexp_replace(pg_stat_activity.query, '[\n\r]+'::text,
+                       ' '::text, 'g'::text)
+                END AS query
+           FROM pg_stat_activity
+        )
+ SELECT stat.datname::name AS db,
+    stat.usename::name AS username,
+    stat.pid,
+    proc.proc_state::text AS state,
+('"'::text || stat.query) || '"'::text AS query,
+    (proc.utime/1000)::bigint AS session_usertime,
+    (proc.stime/1000)::bigint AS session_systemtime,
+    proc.vsize AS session_virtual_memory_size,
+    proc.rss AS session_resident_memory_size,
+    proc.processor AS session_processor_number,
+    proc.rchar AS session_bytes_read,
+    proc.rchar-proc.reads AS session_logical_bytes_read,
+    proc.wchar AS session_bytes_written,
+    proc.wchar-proc.writes AS session_logical_bytes_writes,
+    proc.syscr AS session_read_io,
+    proc.syscw AS session_write_io,
+    proc.reads AS session_physical_reads,
+    proc.writes AS session_physical_writes,
+    proc.cwrites AS session_cancel_writes
+   FROM proctab proc,
+    stat_activity stat
+  WHERE proc.pid = stat.pid;
+```