Multi-node configuration

In addition to the regular TimescaleDB configuration, we recommend that you also configure additional settings specific to multi-node operation.

Update settings

Each of these settings can be configured in the postgresql.conf file on the individual node. The postgresql.conf file is usually in the data directory, but you can locate the correct path by connecting to the node with psql and giving this command:

  2. SHOW config_file;

After you have modified the postgresql.conf file, reload the configuration to see your changes:

  2. pg_ctl reload

max_prepared_transactions

If not already set, ensure that max_prepared_transactions is a non-zero value on all data nodes. We recommend setting it to 150 as a starting point.

enable_partitionwise_aggregate

On the access node, set the enable_partitionwise_aggregate parameter to on. This ensures that queries are pushed down to the data nodes, and improves query performance.

jit

On the access node, set jit to off. Currently, JIT does not work well with distributed queries. However, you can enable JIT on the data nodes succssfully.

statement_timeout

On the data nodes, disable statement_timeout. If you need to enable this, enable and configure it on the access node only. This setting is disabled by default in PostgreSQL, but can be useful if your specific environment is suited.

wal_level

On the data nodes, set the wal_level to logical or higher to move or copy chunks between data nodes. If you are moving many chunks in parallel, consider increasing max_wal_senders and max_replication_slots as well.

Transaction isolation level

For consistency, if the transaction isolation level is set to READ COMMITTED it is automatically upgraded to REPEATABLE READ whenever a distributed operation occurs. If the isolation level is SERIALIZABLE, it is not changed.