General questions about Managed Service for PostgreSQL
What is Managed Service for PostgreSQL?
Managed Service for PostgreSQL is a service that helps you create, operate, and scale PostgreSQL databases in a cloud infrastructure.
With Managed Service for PostgreSQL, you can:
- Create a database with the required performance characteristics.
- Scale processing power and storage dedicated for your databases as needed.
- Get database logs.
Managed Service for PostgreSQL takes on time-consuming PostgreSQL infrastructure administration tasks:
- Monitors resource usage.
- Automatically creates DB backups.
- Provides fault tolerance through automatic failover to backup replicas.
- Keeps database software updated.
You interact with database clusters in Managed Service for PostgreSQL the same way you interact with regular databases in your local infrastructure. This allows you to manage internal database settings to meet your app's requirements.
What part of database management and maintenance is Managed Service for PostgreSQL responsible for?
When creating clusters, Managed Service for PostgreSQL allocates resources, installs the DBMS, and creates databases.
For the created and running databases, Managed Service for PostgreSQL automatically creates backups and applies fixes and updates to the DBMS.
Managed Service for PostgreSQL also provides data replication between database hosts (both inside and between availability zones) and automatically switches the load over to a backup replica in the event of a failure.
Which tasks should I use Managed Service for PostgreSQL for and for which VMs with databases?
Nebius AI offers two ways to work with databases:
- Managed Service for PostgreSQL allows you to operate template databases with no need to worry about administration.
- Compute Cloud virtual machines allow you to create and configure your own databases. This approach allows you to use any database management systems, access databases via SSH, etc.
What is a database host and database cluster?
A database host is an isolated database environment in the cloud infrastructure with dedicated computing resources and reserved data storage.
A database cluster is one or more database hosts between which replication can be configured.
How do I get started with Managed Service for PostgreSQL?
Managed Service for PostgreSQL is available to any registered Nebius AI user.
To create a database cluster in Managed Service for PostgreSQL, you must define its characteristics:
- Host class (performance characteristics such as CPUs, memory, and so on).
- Storage size (reserved in full when you create the cluster).
- The network your cluster will be connected to.
- The number of hosts for the cluster and the availability zone for each host.
For detailed instructions, see Getting started with Managed Service for PostgreSQL.
How many DB hosts can a cluster contain?
Minimum number of hosts: one.
The maximum number of hosts in a cluster is only limited by the requested computing resources and the size of the storage for the cluster.
For more information, see Quotas and limits in Managed Service for PostgreSQL.
How can I access a running DB host?
You can connect to Managed Service for PostgreSQL databases using standard DBMS methods.
Learn more about connecting to clusters.
How many clusters can I create within a single cloud?
MDB technical and organizational limits are given in Quotas and limits in Managed Service for PostgreSQL.
How do I maintain database clusters?
Maintenance in Managed Service for PostgreSQL implies:
- Automatic installation of DBMS updates and revisions for DB hosts (including disabled clusters).
- Changes to the host class and storage size.
- Other Managed Service for PostgreSQL maintenance activities.
For more information, see Maintenance in Managed Service for PostgreSQL.
Which version of PostgreSQL does Managed Service for PostgreSQL use?
Managed Service for PostgreSQL supports PostgreSQL 14, 15, and 16.
What happens when a new DBMS version is released?
The database software is updated when new minor versions are released. The owners of the affected DB clusters receive advanced notice of expected work times and DB availability.
What happens when a DBMS version becomes deprecated?
One month after the database version becomes deprecated, Managed Service for PostgreSQL automatically sends email notifications to the owners of DB clusters created with this version.
New hosts can no longer be created using deprecated DBMS versions. Database clusters are automatically upgraded to the next supported version: seven days after notification for minor versions and one month for major versions. Deprecated major versions are upgraded even if you disabled automatic updates.
How can I change the computing resources and storage size for a database cluster?
You can change computing resources and storage size in the management console. All you need to do is choose a different host class for the required cluster.
The cluster characteristics change within 30 minutes. During this period, other maintenance activities may also be enabled for the cluster, such as installing updates.
Is DB host backup enabled by default?
Yes, backup is enabled by default. For PostgreSQL, a full backup is performed once a day, saving all the database cluster transaction logs. This allows you to restore the cluster state to any point in time during the backup storage period, except for the last 30 seconds.
By default, backups are stored for seven days.
When are backups performed? Is a DB cluster available during backup?
The backup window is an interval during which a full daily backup of the DB cluster is performed. The backup window is from 22:00 to 02:00 (UTC+00:00).
Clusters remain fully accessible during the backup window.
Are PostgreSQL database cluster connections encrypted?
Connections between a database cluster and an application are always encrypted using SSL. You cannot disable cluster connection encryption.
What is a read-only replica in PostgreSQL?
A read-only replica is a host in a PostgreSQL DB cluster that can only be read. Its data is synced with the master host (applies only if the cluster has more than 1 host). You can use a read-only replica to reduce the load on the DB master host with a large number of read requests.
What metrics and processes can be tracked using monitoring?
For all DBMS types, you can track:
- CPU, memory, network, or disk usage, in absolute terms.
- The amount of data in the DB cluster and the remaining free space in data storage.
For DB hosts, you can track metrics specific to the corresponding type of DBMS. For example, for PostgreSQL, you can track:
- Average query execution time
- Number of queries per second
- Number of errors in logs.
Monitoring can be performed with a minimum granularity of 5 seconds.
Can I get logs of my operations with services?
Yes, you can request log records about your resources from Nebius AI services. For more information, see Data requests.
What limitations are imposed on PostgreSQL database clusters?
For more information about Managed Service for PostgreSQL limits, see Quotas and limits in Managed Service for PostgreSQL. Characteristics of clusters that can be created using Managed Service for PostgreSQL are given in PostgreSQL host classes.
What PostgreSQL extensions are supported in Managed Service for PostgreSQL?
The list of supported PostgreSQL extensions is provided in Managing extensions.
Which data center stores PostgreSQL cluster backups?
Cluster backups are stored and available in all three data centers.
Can I get superuser privileges in PostgreSQL?
No, you cannot. Superuser privileges are not available to Managed Service for PostgreSQL users. The highest privileges for working with clusters are granted to users with the mdb_admin
role.
Are there any specifics of or restrictions for using the garbage collector in Managed Service for PostgreSQL clusters?
Managed Service for PostgreSQL clusters support all parameters of the VACUUM command
- To run
VACUUM FULL
, the user must have themdb_admin
role. The VACUUM FULL command does not affect system views. - In PostgreSQL version 14, the functionality of the
INDEX_CLEANUP
parameter is enhanced: it now has theAUTO
value by default. This means that theVACUUM
command skips index cleanup if it is considered unfeasible. To ensure backward compatibility with the previous PostgreSQL versions, setINDEX_CLEANUP
toON
.
Why is a cluster working slowly even though it still has free computing resources?
Perhaps, the maximum storage IOPS and bandwidth values are insufficient for processing the current number of requests. In this case, throttling is triggered and the performance of the entire cluster degrades.
The maximum IOPS and bandwidth values increase by a fixed value when the storage size increases by a certain step. The step and increment values depend on the disk type:
Disk type | Step, GB | Max IOPS increase (read/write) | Max bandwidth increase (read/write), MB/s |
---|---|---|---|
network-hdd |
256 | 300/300 | 30/30 |
network-ssd |
32 | 1,000/1,000 | 15/15 |
To increase the maximum IOPS and bandwidth values and make throttling less likely, increase the storage size when you update your cluster.
If you are using the network-hdd
storage type, consider switching to network-ssd
by restoring the cluster from a backup.