Storage

Configure the storage backend for Chronicle Server.

Storage types

Type	Description
MongoDB	MongoDB (default)
PostgreSql	PostgreSQL
MsSql	Microsoft SQL Server
Sqlite	SQLite (embedded, file-based)
InMemory	In-memory (ephemeral, non-durable)

MongoDB

{
  "storage": {
    "type": "MongoDB",
    "connectionDetails": "mongodb://localhost:27017"
  }
}

PostgreSQL

{
  "storage": {
    "type": "PostgreSql",
    "connectionDetails": "Host=localhost;Port=5432;Database=chronicle;Username=chronicle;Password=secret"
  }
}

Microsoft SQL Server

{
  "storage": {
    "type": "MsSql",
    "connectionDetails": "Server=localhost;Database=chronicle;User Id=chronicle;Password=secret;TrustServerCertificate=True"
  }
}

SQLite

{
  "storage": {
    "type": "Sqlite",
    "connectionDetails": "Data Source=/data/chronicle.db"
  }
}

In-memory

The in-memory backend keeps every event sequence, observer, read-model sink, and system record in process memory. There is no connection string, and connectionDetails is ignored.

{
  "storage": {
    "type": "InMemory"
  }
}

Danger

The in-memory backend is not durable — all data is lost when the process exits, and it is scoped to a single process (it does not share state across a cluster). Use it for tests, samples, and ephemeral environments, not for production data.

When you host Chronicle programmatically, select the in-memory backend with the WithInMemory() builder extension instead of configuration:

C#

siloBuilder.AddChronicleToSilo(chronicle => chronicle.WithInMemory());

Property	Type	Required	Description
type	string	Yes	Storage type: MongoDB, PostgreSql, MsSql, Sqlite, or InMemory
connectionDetails	string	Conditional	Connection string for the chosen storage backend. Required for all backends except InMemory, which ignores it