feat: count number of PostgreSQL pid files

Author: casperr0

mamonsu/plugins/pgsql/connections.py

@@ -23,7 +23,14 @@ class Connections(Plugin):
          'number of disabled',
          '00CCCC')
     ]
+    # ( key, name, graph)
+    Item_ppid_children = [
+        ('pgsql.count_all_pids{0}',
+         'Number of PostgreSQL parent pid children',
+         ('PostgreSQL: count children of PostgreSQL parent pid', 'BBB000', 0)),
+    ]
     Max_connections = None
+
     query_agent = "select count(*) from pg_catalog.pg_stat_activity where state = '{0}';"
     query_agent_total = "select count(*) from pg_catalog.pg_stat_activity where state is not null ;"
     query_agent_waiting_new_v = "select count(*) from pg_catalog.pg_stat_activity where state is not null and " \
@@ -74,6 +81,11 @@ def run(self, zbx):
             self.Max_connections = result[0][0]
         zbx.send('pgsql.connections[max_connections]', int(self.Max_connections))
 
+        # get number of child pids of ppid
+        num_of_children_pids = self.get_num_of_children_pids()
+        key = self.Item_ppid_children[0][0].format('[]')
+        zbx.send(key, num_of_children_pids+1)
+
     def items(self, template):
         result = template.item({
             'name': 'PostgreSQL: number of total connections',
@@ -97,6 +109,11 @@ def items(self, template):
                 'key': self.right_type(self.key, item[1]),
                 'delay': self.plugin_config('interval')
             })
+        result += template.item({
+            'name': 'PostgreSQL: number of child pids',
+            'key': self.right_type(self.Item_ppid_children[0][0]),
+            'delay': self.plugin_config('interval')
+        })
         return result
 
     def graphs(self, template):
@@ -118,6 +135,10 @@ def graphs(self, template):
             'key': self.right_type(self.key, "max_connections"),
             'color': '00BB00'
         })
+        items.append({
+            'key': self.right_type(self.Item_ppid_children[0][0]),
+            'color': '0BB000'
+        })
         graph = {'name': 'PostgreSQL connections', 'items': items}
         return template.graph(graph)
 

mamonsu/plugins/pgsql/plugin.py

@@ -1,3 +1,4 @@
+import psutil
 from mamonsu.lib.plugin import Plugin, PluginDisableException
 from .pool import Pooler
 
@@ -33,6 +34,22 @@ def check(self, extension):
 
         return self._ext_installed
 
+    @staticmethod
+    def get_num_of_children_pids():
+        result = Pooler.query("SELECT pg_backend_pid();")
+        pid = result[0][0]
+        with open('/proc/{pid}/status'.format(pid=int(pid)), 'r') as f:
+            for line in f:
+                data = line.split()
+                if data[0] == "PPid:":
+                    ppid = data[1]
+        try:
+            parent = psutil.Process(int(ppid))
+        except psutil.NoSuchProcess:
+            raise PluginDisableException("Unable to get parent process using psutil lib.")
+        children = parent.children(recursive=True)
+        return len(children)
+
     def disable_and_exit_if_extension_is_not_installed(self, ext, db=None):
         if not self.extension_installed(ext, db=db, silent=True):
             self.disable()