6 TimescaleDB setup

Overview

Zabbix supports TimescaleDB, a PostgreSQL-based database solution of automatically partitioning data into time-based chunks to support faster performance at scale.

Currently, TimescaleDB is not supported by Zabbix proxy.

Instructions on this page can be used for the following scenarios:

  • Creating a TimescaleDB database or migrating from existing PostgreSQL tables to TimescaleDB (see Configuration).
  • Upgrading an existing TimescaleDB database schema when upgrading Zabbix (see Upgrading TimescaleDB schema).

Configuration

We assume that TimescaleDB extension has been already installed on the database server (see installation instructions in Timescale documentation).

TimescaleDB extension must also be enabled for the specific DB by executing:

echo "CREATE EXTENSION IF NOT EXISTS timescaledb CASCADE;" | sudo -u postgres psql zabbix

Running this command requires database administrator privileges.

If you use a database schema other than 'public' you need to add a SCHEMA clause to the command above. E.g.:
echo "CREATE EXTENSION IF NOT EXISTS timescaledb SCHEMA yourschema CASCADE;" | sudo -u postgres psql zabbix

Then run the postgresql/timescaledb/schema.sql script. For new installations, the script must be run after the regular PostgreSQL database has been created with initial schema/data (see database creation).

cat /usr/share/zabbix-sql-scripts/postgresql/timescaledb/schema.sql | sudo -u zabbix psql zabbix

Please ignore warning messages informing that the best practices are not followed while running schema.sql script on TimescaleDB version 2.9.0 and higher. Regardless of this warning, the configuration will be completed successfully.

The migration of existing history, trends and audit log data may take a lot of time. Zabbix server and frontend must be down for the period of migration.

The schema.sql script sets the following housekeeping parameters:

  • Override item history period
  • Override item trend period

In order to use partitioned housekeeping for history and trends, both these options must be enabled. It is also possible to enable override individually either for history only or trends only.

For PostgreSQL and TimescaleDB, the postgresql/timescaledb/schema.sql script sets two additional parameters:

  • Enable compression
  • Compress records older than 7 days

To successfully remove compressed data by housekeeper, both Override item history period and Override item trend period options must be enabled. If override is disabled and tables have compressed chunks, the housekeeper will not remove data from these tables, and warnings about incorrect configuration will be displayed in the Housekeeping and System information sections.

All of these parameters can be changed in AdministrationHousekeeping after the installation.

You may want to run the timescaledb-tune tool provided by TimescaleDB to optimize PostgreSQL configuration parameters in your postgresql.conf.

Upgrading TimescaleDB schema

When upgrading Zabbix to a version that contains new TimescaleDB hypertables, Zabbix server does not automatically configure those hypertables (for example, when upgrading from Zabbix 6.4 to 7.2, as versions 7.0.0 and 7.0.2 have introduced new hypertables).

To configure new TimescaleDB hypertables, follow these steps:

  1. Start Zabbix server; this upgrades the existing database.
  2. Check the server log file that the database upgrade is completed; when completed, stop Zabbix server. Note that the server logs a warning if it attempts to enable compression for a table that is not a hypertable.
  3. Run the postgresql/timescaledb/schema.sql script; this configures the new TimescaleDB hypertables. Note that, since Zabbix 7.0.0, the script's location and name have changed from postgresql/timescaledb.sql to postgresql/timescaledb/schema.sql.

Please ignore warning messages informing that the best practices are not followed while running schema.sql script on TimescaleDB version 2.9.0 and higher. Regardless of this warning, the configuration will be completed successfully.

TimescaleDB compression

Native TimescaleDB compression is supported for all Zabbix tables that are TimescaleDB hypertables. During the upgrade or migration to TimescaleDB, initial compression of the large tables may take a lot of time.

Note that compression is supported under the "timescale" Timescale Community license and it is not supported under "apache" Apache 2.0 license. If Zabbix detects that compression is not supported a warning message is written into the Zabbix server log and users cannot enable compression in the frontend.

Users are encouraged to get familiar with compression in Timescale documentation before using compression.

Note that there are certain limitations imposed by compression, specifically:

  • Compressed chunk modifications (inserts, deletes, updates) are not allowed
  • Schema changes for compressed tables are not allowed.

Compression settings can be changed in the History and trends compression block in AdministrationHousekeeping section of Zabbix frontend.

Parameter Default Comments
Enable compression Enabled Checking or unchecking the checkbox does not activate/deactivate compression immediately. Because compression is handled by the Housekeeper, the changes will take effect in up to 2 times HousekeepingFrequency hours (set in zabbix_server.conf)

After disabling compression, new chunks that fall into the compression period will not be compressed. However, all previously compressed data will stay compressed. To uncompress previously compressed chunks, follow the instructions in Timescale documentation.

When upgrading from older versions of Zabbix with TimescaleDB support, compression will not be enabled by default.
Compress records older than 7d This parameter cannot be less than 7 days.

Due to immutability of compressed chunks all late data (e.g. data delayed by a proxy) that is older than this value will be discarded.