Validators under heavy RPC loads, such as when serving getProgramAccounts calls, can fall behind the network. To solve this problem, the validator has been enhanced to support a plugin mechanism, called a "Geyser" plugin, through which the information about accounts, slots, blocks, and transactions can be transmitted to external data stores such as relational databases, NoSQL databases or Kafka. RPC services then can be developed to consume data from these external data stores with the possibility of more flexible and targeted optimizations such as caching and indexing. This allows the validator to focus on processing transactions without being slowed down by busy RPC requests.
This document describes the interfaces of the plugin and the referential plugin implementation for the PostgreSQL database.
solana-geyser-plugin-interface— This crate defines the plugin interfaces.
solana-accountsdb-plugin-postgres— The crate for the referential plugin implementation for the PostgreSQL database.
The Plugin interface is declared in
is defined by the trait
GeyserPlugin. The plugin should implement the
trait and expose a "C" function
_create_plugin to return the pointer to this
trait. For example, in the referential implementation, the following code
instantiates the PostgreSQL plugin
GeyserPluginPostgres and returns its
A plugin implementation can implement the
on_load method to initialize itself.
This function is invoked after a plugin is dynamically loaded into the validator
when it starts. The configuration of the plugin is controlled by a configuration
file in JSON5 format. The JSON5 file must have a field
libpath that points
to the full path name of the shared library implementing the plugin, and may
have other configuration information, like connection parameters for the external
database. The plugin configuration file is specified by the validator's CLI
--geyser-plugin-config and the file must be readable to the
Please see the config file for the referential PostgreSQL plugin below for an example.
The plugin can implement the
on_unload method to do any cleanup before the
plugin is unloaded when the validator is gracefully shutdown.
The plugin framework supports streaming either accounts, transactions or both. A plugin uses the following function to indicate if it is interested in receiving account data:
And it uses the following function to indicate if it is interested in receiving transaction data:
The following method is used for notifying on an account update:
ReplicaAccountInfoVersions struct contains the metadata and data of the account
slot points to the slot the account is being updated at. When
is_startup is true, it indicates the account is loaded from snapshots when
the validator starts up. When
is_startup is false, the account is updated
when processing a transaction.
The following method is called when all accounts have been notified when the validator restores the AccountsDb from snapshots at startup.
update_account is called during processing transactions, the plugin
should process the notification as fast as possible because any delay may
cause the validator to fall behind the network. Persistence to external data
store is best to be done asynchronously.
The following method is used for notifying slot status changes:
To ensure data consistency, the plugin implementation can choose to abort the validator in case of error persisting to external stores. When the validator restarts the account data will be re-transmitted.
The following method is used for notifying transactions:
contains the information about a streamed transaction. It wraps
slot points to the slot the transaction is executed at.
For more details, please refer to the Rust documentation in
solana-accountsdb-plugin-postgres repository implements a plugin storing
account data to a PostgreSQL database to illustrate how a plugin can be
The plugin is configured using the input configuration file. An example configuration file looks like the following:
port control the PostgreSQL configuration
information. For more advanced connection options, please use the
connection_str field. Please see [Rust postgres configuration]
To improve the throughput to the database, the plugin supports connection pooling
using multiple threads, each maintaining a connection to the PostgreSQL database.
The count of the threads is controlled by the
threads field. A higher thread
count usually offers better performance.
To further improve performance when saving large numbers of accounts at
startup, the plugin uses bulk inserts. The batch size is controlled by the
batch_size parameter. This can help reduce the round trips to the database.
panic_on_db_errors can be used to panic the validator in case of database
errors to ensure data consistency.
accounts_selector can be used to filter the accounts that should be persisted.
For example, one can use the following to persist only the accounts with particular Base58-encoded Pubkeys,
Or use the following to select accounts with certain program owners:
To select all accounts, use the wildcard character (*):
transaction_selector, controls if and what transactions to store.
If this field is missing, none of the transactions are stored.
For example, one can use the following to select only the transactions referencing accounts with particular Base58-encoded Pubkeys,
mentions field supports wildcards to select all transaction or
all 'vote' transactions. For example, to select all transactions:
To select all vote transactions:
Please follow PostgreSQL Ubuntu Installation on instructions to install the PostgreSQL database server. For example, to install postgresql-14,
Modify the pg_hba.conf as necessary to grant the plugin to access the database. For example, in /etc/postgresql/14/main/pg_hba.conf, the following entry allows nodes with IPs in the CIDR 10.138.0.0/24 to access all databases. The validator runs in a node with an ip in the specified range.
It is recommended to run the database server on a separate node from the validator for better performance.
Please refer to the PostgreSQL Server Configuration for configuration details. The referential implementation uses the following configurations for better database performance in the /etc/postgresql/14/main/postgresql.conf which are different from the default postgresql-14 installation.
The sample postgresql.conf can be used for reference.
Start the server:
Create the database. For example, the following creates a database named 'solana':
Create the database user. For example, the following creates a regular user named 'solana':
Verify the database is working using psql. For example, assuming the node running PostgreSQL has the ip 10.138.0.9, the following command will land in a shell where SQL commands can be entered:
Use the create_schema.sql to create the objects for storing accounts and slots.
Download the script from github:
Then run the script:
After this, start the validator with the plugin by using the
argument mentioned above.
To destroy the database objects, created by
To capture account historical data, in the configuration file, turn
store_account_historical_data to true.
And ensure the database trigger is created to save data in the
account are updated, as shown in
The trigger can be dropped to disable this feature, for example,
Over time, the account_audit can accumulate large amount of data. You may choose to limit that by deleting older historical data.
For example, the following SQL statement can be used to keep up to 1000 of the most recent records for an account:
The following are the tables in the Postgres database
|account_audit||Account historical data|
When a validator lacks sufficient compute power, the overhead of saving the account data can cause it to fall behind the network especially when all accounts or a large number of accounts are selected. The node hosting the PostgreSQL database need to be powerful enough to handle the database loads as well. It has been found using GCP n2-standard-64 machine type for the validator and n2-highmem-32 for the PostgreSQL node is adequate for handling transmiting all accounts while keeping up with the network. In addition, it is best to keep the validator and the PostgreSQL in the same local network to reduce latency. You may need to size the validator and database nodes differently if serving other loads.