Add cleanup script for db partitions

zabbix-server/files/partition-cleanup.py

+#!/usr/bin/env python
+# encoding: utf-8
+from __future__ import print_function
+import psycopg2
+import re
+from datetime import datetime, date, timedelta
+
+DATE_PATTERN = r'(?P<date>\d{6})'
+
+def get_date(name):
+    match = re.search(DATE_PATTERN, name)
+    date_str = match.group("date")
+    year_part, month_part = date_str[:4], date_str[4:]
+    return date(year=int(year_part), month=int(month_part), day=1)
+
+def get_partitions(connection, tablename):
+    cursor = connection.cursor()
+    cursor.execute("SELECT relname FROM pg_inherits i "
+        "JOIN pg_class c on c.oid = inhrelid "
+        "WHERE inhparent = '{}'::regclass".format(tablename))
+    return cursor.fetchall()
+
+def delete_partition(connection, partition_name, partitions_schema="partitions"):
+    cursor = connection.cursor()
+    cursor.execute("DROP TABLE {}.{}".format(partitions_schema, partition_name))
+    return connection.commit()
+
+if __name__ == "__main__":
+    today = datetime.now().date()
+    import argparse
+    parser = argparse.ArgumentParser("Helper script to keep the zabbix "
+        "database s̶m̶a̶l̶l̶ not tooo large.")
+    parser.add_argument("table", help="Tablename to remove partitions from "
+        "(e.g. „public.history“).")
+    parser.add_argument("--db", default="zabbix",
+        help="Name of the database to operate on.")
+    parser.add_argument("--months", default=3, type=int,
+        help="Number of months after which partitions should be dropped.")
+    parser.add_argument("--dryrun", action="store_true", default=False,
+        help="Do not actually delete partitions.")
+    parser.add_argument("--partitions-schema", default="partitions",
+        help="Schema name of partitions.")
+    arguments = parser.parse_args()
+
+    min_drop_delta = timedelta(days=31*arguments.months)
+
+    connection = psycopg2.connect(dbname=arguments.db)
+    for partitions in get_partitions(connection, arguments.table):
+        partition_name, = partitions
+        partition_date = get_date(partition_name)
+        should_delete = today - partition_date > min_drop_delta
+        if not should_delete:
+            continue
+        if arguments.dryrun:
+            print("Would drop partition {}.".format(partition_name))
+        else:
+            print("Dropping partition {}.".format(partition_name))
+            delete_partition(connection, partition_name,
+                partitions_schema=arguments.partitions_schema)
+    connection.close()

zabbix-server/tasks/main.yml

@@ -126,6 +126,33 @@
     - database
     - zabbix
 
+- name: upload the partition cleanup script
+  copy:
+    src: partition-cleanup.py
+    dest: /usr/local/bin/
+    owner: root
+    group: root
+    mode: 0755
+  delegate_to: "{{ zabbix_db_host }}"
+  tags:
+    - database
+    - zabbix
+
+- name: let's clean the history partition up once per month
+  cron:
+    name: "clean zabbix-db {{item.table}} partition"
+    special_time: monthly
+    job: "/usr/local/bin/partition-cleanup.py public.{{item.table}} --months {{item.months}}"
+    state: present
+    user: postgres
+  delegate_to: "{{ zabbix_db_host }}"
+  with_items:
+    - { table: "history", months: 4 }
+    - { table: "trends", months: 13 }
+  tags:
+    - database
+    - zabbix
+
 - name: include snmp-features
   include: snmp.yml