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Configuration

Configuring DBOS​

To configure DBOS, pass in a configuration with DBOS.setConfig before you call DBOS.launch. For example:

DBOS.setConfig({
  name: 'my-app',
  systemDatabaseUrl: process.env.DBOS_SYSTEM_DATABASE_URL,
});
await DBOS.launch();

A configuration object has the following fields. All fields except name are optional.

export interface DBOSConfig {
  name?: string;
  applicationVersion?: string;
  executorID?: string;

  systemDatabaseUrl?: string;
  systemDatabasePoolSize?: number;
  systemDatabasePollingConcurrency?: number;
  systemDatabaseSchemaName?: string;
  systemDatabasePool?: Pool;

  tracingEnabled?: boolean;
  otelAttributeFormat?: 'legacy' | 'semconv';
  logLevel?: string;
  logger?: DLogger;
  enableOTLP?: boolean;
  otlpLogsEndpoints?: string[];
  otlpTracesEndpoints?: string[];

  runAdminServer?: boolean;
  adminPort?: number;

  listenQueues?: (WorkflowQueue | string)[];

  schedulerPollingIntervalMs?: number;

  serializer?: DBOSSerializer;
}

Application Settings​

  • name: Your application's name.
  • applicationVersion: The code version for this application and its workflows. Workflow versioning is documented here.
  • executorID: A unique process ID used to identify the application instance in distributed environments. If using DBOS Conductor or Cloud, this is set automatically.

Database Connection Settings​

postgresql://[username]:[password]@[hostname]:[port]/[database name]

The default is:

postgresql://postgres:dbos@localhost:5432/[application name]_dbos_sys

If the Postgres database referenced by this connection string does not exist, DBOS will attempt to create it.

  • systemDatabasePoolSize: The size of the connection pool used for the DBOS system database. Defaults to 10.
  • systemDatabasePollingConcurrency: The maximum number of database-backed polling reads from wait operations (such as getResult, waitAll, waitFirst, recv, and getEvent) that may run concurrently against the system database pool. This prevents high-fan-out polling from checking out every connection in the pool and starving control-plane operations (such as enqueue/dequeue, status writes, recovery, and cancellation). Defaults to half the systemDatabasePoolSize (minimum 1). Set to a non-positive value to disable the limit.
  • systemDatabaseSchemaName: Postgres schema name for DBOS system tables. Defaults to dbos.
  • systemDatabasePool: A custom node-postgres connection pool to use to connect to your system database. If provided, DBOS will not create a connection pool but use this instead.

Logging and Tracing Settings​

  • tracingEnabled: Enable DBOS trace generation. Use this with an external OTLP TracerProvider. Traces will be collected and exported by your existing provider. Tutorial here.
  • otelAttributeFormat: Naming convention for DBOS-emitted span attributes. Defaults to 'legacy', which emits the original camelCase names (operationUUID, executorID, …) for backward compatibility. Set to 'semconv' to emit OTel-style names under the dbos.* namespace (dbos.operation.workflow_id, dbos.executor.id, …), which follow the OTel attribute naming spec and avoid colliding with attributes set by other instrumentation. The flag is process-wide; user-supplied attributes are passed through verbatim either way.
  • logLevel: Configure the DBOS logger severity. Defaults to info.
  • logger: A custom logger implementing the DLogger interface, to which DBOS directs all its internal logging, replacing the built-in console and OTLP log sinks. When set, logLevel does not filter calls to it (level routing is the logger's job), logs are not exported over OTLP even if enableOTLP is on (traces are unaffected), and DBOS never flushes or closes it (the caller owns its lifecycle).
  • enableOTLP: Enable the built-in DBOS OpenTelemetry TracerProvider. Defaults to False. Do not set if using an external OTLP TracerProvider.
  • otlpTracesEndpoints: If using the built-in DBOS OpenTelemetry TracerProvider, a list of receivers to which to send traces.
  • otlpLogsEndpoints: If using the built-in DBOS OpenTelemetry TracerProvider, a list of receivers to which to send logs.

Admin Server Settings​

  • runAdminServer: Whether to run an HTTP admin server for workflow management operations. Defaults to True.
  • adminPort: The port on which the admin server runs. Defaults to 3001.

Queue Settings​

  • listenQueues: This process should only listen to (dequeue and execute workflows from) these queues. Each entry is either a WorkflowQueue instance or a queue name. Names that do not match any queue at launch are deferred — a database-backed queue registered later under that name will be picked up automatically.

Scheduler Settings​

  • schedulerPollingIntervalMs: How frequently (in milliseconds) the scheduler polls the database for schedule changes. Defaults to 30000 (30 seconds).

Serialization Settings​

Custom Serialization​

DBOS must serialize data such as workflow inputs and outputs and step outputs to store it in the system database. By default, data is serialized with JSON, but you can optionally supply a custom serializer through DBOS configuration. A custom serializer must match this interface:

interface DBOSSerializer {
  stringify: (obj: unknown) => string | Promise<string>;
  parse: (text: string | null | undefined) => unknown | Promise<unknown>;
  name: () => string; // `name` is stored with the resulting string to ensure the correct deserializer is used.
}

Both stringify and parse may be synchronous or asynchronous.

For example, here is how to configure DBOS to use a Base64-encoded JSON serializer:

import { DBOS, DBOSSerializer } from "@dbos-inc/dbos-sdk";

const base64Serializer: DBOSSerializer = {
  parse: (text) => {
    // Parsers must always return null when receiving null or undefined
    if (text === null || text === undefined) return null;
    return JSON.parse(Buffer.from(text, 'base64').toString());
  },
  stringify: (obj) => {
    // JSON.stringify doesn't handle undefined, so convert it to null instead
    if (obj === undefined) obj = null;
    return Buffer.from(JSON.stringify(obj)).toString('base64');
  },
  name: () => "simple_json",
};

const config = // ...
config.serializer = base64Serializer;
DBOS.setConfig(config);
await DBOS.launch();

DBOS Configuration File​

Some tools in the DBOS ecosystem, including DBOS Cloud and the DBOS CLI, are configured by a dbos-config.yaml file.

Here is an example configuration file with default parameters:

name: my-app
language: node
system_database_url: ${DBOS_SYSTEM_DATABASE_URL}
runtimeConfig:
  start:
    - node dist/main.js

Configuration File Fields​

info

You can use environment variables for configuration values through the syntax field: ${VALUE}.

Each dbos-config.yaml file has the following fields and sections:

  • name: Your application's name. Must match the name supplied to DBOS.setConfig().
  • language: The application language. Must be set to node for TypeScript applications.
  • system_database_url: The connection string to your DBOS system database. This connection string is used by the DBOS CLI. It has the same format as the system_database_url you pass to the DBOS constructor.
  • runtimeConfig:
    • start: (required only in DBOS Cloud) The command(s) with which to start your app. Called from npx dbos start, which is used to start your app in DBOS Cloud.
    • setup: (optional) Setup commands to run before your application is built in DBOS Cloud. Used only in DBOS Cloud. Documentation here.

Configuration Schema File​

There is a schema file available for the DBOS configuration file schema in GitHub. This schema file can be used to provide an improved YAML editing experience for developer tools that leverage it. For example, the Visual Studio Code RedHat YAML extension provides tooltips, statement completion and real-time validation for editing DBOS config files. This extension provides multiple ways to associate a YAML file with its schema. The easiest is to simply add a comment with a link to the schema at the top of the config file:

# yaml-language-server: $schema=https://github.com/dbos-inc/dbos-transact-py/blob/main/dbos/dbos-config.schema.json