FAQ

The following are a few FAQ to provide insight into the PostgreSQL product.

Provisioning and configuration

On what server instances is PostgreSQL offered?

DBaaS offers PostgreSQL on virtual servers. Cloud Cubes support may be introduced in the future.

Which replication modes are supported for PostgreSQL clusters?

PostgreSQL supports only ASYNCHRONOUS and STRICTLY_SYNCHRONOUS replication modes. Existing clusters using SYNCHRONOUS mode can switch to one of these supported replication modes using the API.

Connection pooling

Is there a connection pooling option for PostgreSQL?

IONOS CLOUD DBaaS does not provide connection pooling. However, you may use a connection pooler (such as pgbouncer) between your application and the database.

To use DBaaS managed pgbouncer, see Activate a PostgreSQL Connection Pooler.

After the connection limit has been reached, will there be an error?

Depending on the library you are using, you get the following error:

Failed to create DB connection: addr x.x.x.x:5432: connection refused.

How do we prevent reaching the connection limit?

The best way to manage connections is to have your application maintain a pool of at least 10-20 connections. It is not considered good practice to have many DB connections. However, letting the user configure max_connections themselves in the future is an option.

Can I scale the deployment to increase its connection limit?

Yes. For more information, see Connection Limits.

Backup and recovery

What are the supported backup methods?

We provide automated backups in IONOS CLOUD. If you want to use other backup options, you may use a client-side tool, such as pg_dump.

Why cannot I restore to the time I specified?

If you are receiving an error message, Parameter out of bounds: The recovery target time is before the newest basebackup., check the earliestRecoveryTargetTime of your backup. Your target time for the restore needs to be after this timestamp. You can use an earlier backup with earliestRecoveryTargetTime for your cluster if you have one.

If the earliestRecoveryTargetTime is missing in your backup, the cluster from where you want to restore wasn't able to do a base backup. It can happen when you quickly delete a newly created cluster, since the base backup will be triggered up to a minute after the cluster is available.

Performance and scaling

What are the main considerations for latency and performance?

The number of standby nodes (in addition to the primary node) doesn't really matter. If you have one or ten, it makes no difference. Synchronous modes are slower in write performance due to increased communication latency between a primary and a standby node.

Monitoring

Which metrics are available for PostgreSQL?

Cluster metrics include connections count, CPU usage, disk Input/Output (I/O) time, instance count, memory usage, memory availability, Linux load average, disk space, index scans, and sequential scans. For more information, see Metrics Overview. You can view the detailed performance metrics using the Telemetry API.

PostgreSQL v2 API

What is the PostgreSQL v2 API?

The PostgreSQL v2 API is a modernized, future-proof, and developer-friendly REST interface designed to provision and manage highly available PostgreSQL clusters. It introduces refined resource modeling, region-specific routing, and OpenAPI best-practice error handling. For more information, see Features.

What authentication methods are supported in PostgreSQL v2 API?

To align with modern security best practices, the v2 API requires API tokens (tokenAuth). Legacy basic authentication (basicAuth), which is available in PostgreSQL v1, is no longer supported.

What endpoints do I use to connect to the PostgreSQL v2 API?

The PostgreSQL v2 API utilizes multiple region-specific endpoints. You must direct your requests to the specific region where your database is deployed. For information on supported regions and their corresponding endpoints, see Endpoints.

Can I use PostgreSQL v2 API for production applications?

Yes. The PostgreSQL v2 API is in General Availability (GA) phase starting May 18, 2026, and is supported for production workloads across all IONOS CLOUD regions where DBaaS PostgreSQL is offered. No prior whitelisting or contract activation is required.

Can I connect to the default postgres database in the PostgreSQL v2 API?

No, you cannot. The v2 API intentionally denies this access. If you attempt to connect to it using your v2 cluster credentials, you receive a "FATAL: permission denied for database postgres error". You must instead connect to the specific database you defined within your cluster configuration during provisioning.

What is the "Ensure" pattern in PostgreSQL v2 API?

The PostgreSQL v2 API introduces the "Ensure" pattern for cluster management. By utilizing PUT semantics such as PUT /clusters/{clusterId}, you can safely and idempotently create a new cluster or update an existing one to match your desired state. Non-present data will be filled with defaults.

How do I manage users and databases in PostgreSQL v2 API?

You define your main user credentials, including the username, password, and database name, directly within the credentials property of your cluster payload during provisioning or when modifying the cluster.

How are backups and backup locations managed in PostgreSQL v2 API?

Backups have been elevated to a dedicated top-level /backups endpoint, rather than being strictly nested under individual clusters. Additionally, the API introduces BackupLocations (/backup-locations) as an explicit resource, allowing you to query and configure the geographic safety of your backups.

Does the PostgreSQL v2 API support filtering and pagination?

Yes. Every listing endpoint in the v2 API, such as /clusters or /backups supports standardized pagination (using limit and offset) and robust filtering. It allows you to search your resources by attributes such as filter.state, filter.name, or filter.clusterId.

Can I view cluster logs using the PostgreSQL v2 API?

No, the explicit /logs endpoint available in v1 has been removed in the PostgreSQL v2 specification, indicating a shift in how operational observability and log access are managed.

How can I evaluate the cluster healthiness?

Use the cluster metrics reporting to monitor the health of the cluster. The Retrieve Cluster API only provides the status of the cluster.

How to activate the logs and metrics for my cluster?

In Create Cluster or Ensure Cluster, set the logsEnabled to true to view the logs reporting and set the metricsEnabled to true to view the metrics reporting.

Note:

• Even if logsEnabled and metricsEnabled is set to true, logs and metrics reporting are available only when you activate the Observability Logging Service and Monitoring Service.

• Activating the Logging Service and Monitoring Service will incur additional costs.

How can I activate central Logging Service?

To activate the Logging Service, use the Ensure Central Logging API with enabled parameter set to true.

How can I activate central Monitoring Service?

To activate the Monitoring Service, use the Ensure Central Monitoring API with the enabled parameter set to true.