Camel Persistence

camel-persistence is a modular persistence layer for Camel-style flow state, with pluggable backends.

Description: Modular flow-state persistence for Apache Camel with pluggable JDBC, Redis, and IC4J/ICP backends.

Documentation

• Third-Party Component Integration Guide
• Maven Central Deployment Guide

Topics

Modules

• camel-persistence-core — core contracts and factory (FlowStateStore, PersistenceConfiguration, FlowStateStoreFactory)
• camel-persistence-jdbc — JDBC-backed implementation
• camel-persistence-redis — Redis-backed implementation
• camel-persistence-ic4j — IC4J/ICP-backed implementation using the ICP Camel component
• camel-persistence-testkit — backend contract test base (FlowStateStoreContractSuite)

Version

Current stable release: 1.3.1

Canonical root artifact (parent POM): io.dscope.camel:camel-persistence:1.3.1

Canonical Maven package URL (PURL): pkg:maven/io.dscope.camel/camel-persistence

Build & Install (local Maven)

From repository root:

mvn clean test install

This runs the reactor tests, packages each module, and installs artifacts under ~/.m2/repository/io/dscope/camel/.... Redis-backed tests use redis://localhost:6379 by default when Redis is running locally.

Developer Commands

From repository root:

# Full verification and local install
mvn clean test install

# Test only
mvn test

# Build one module with reactor dependencies
mvn -pl camel-persistence-core -am test

Dependency Examples (for other projects)

Use core plus one backend module (jdbc, redis, or ic4j).

Maven

<dependency>
  <groupId>io.dscope.camel</groupId>
  <artifactId>camel-persistence-core</artifactId>
  <version>1.3.1</version>
</dependency>

<dependency>
  <groupId>io.dscope.camel</groupId>
  <artifactId>camel-persistence-jdbc</artifactId>
  <version>1.3.1</version>
</dependency>

Maven (Redis backend)

<dependency>
  <groupId>io.dscope.camel</groupId>
  <artifactId>camel-persistence-core</artifactId>
  <version>1.3.1</version>
</dependency>

<dependency>
  <groupId>io.dscope.camel</groupId>
  <artifactId>camel-persistence-redis</artifactId>
  <version>1.3.1</version>
</dependency>

Maven (IC4J / ICP backend)

<dependency>
  <groupId>io.dscope.camel</groupId>
  <artifactId>camel-persistence-core</artifactId>
  <version>1.3.1</version>
</dependency>

<dependency>
  <groupId>io.dscope.camel</groupId>
  <artifactId>camel-persistence-ic4j</artifactId>
  <version>1.3.1</version>
</dependency>

For Redis cache plus IC4J durable persistence, include camel-persistence-core, camel-persistence-redis, and camel-persistence-ic4j, then set camel.persistence.backend=redis_ic4j.

Gradle (Groovy DSL)

dependencies {
  implementation 'io.dscope.camel:camel-persistence-core:1.3.1'
  implementation 'io.dscope.camel:camel-persistence-jdbc:1.3.1'
}

For Redis backend:

dependencies {
  implementation 'io.dscope.camel:camel-persistence-core:1.3.1'
  implementation 'io.dscope.camel:camel-persistence-redis:1.3.1'
}

For IC4J / ICP backend:

dependencies {
  implementation 'io.dscope.camel:camel-persistence-core:1.3.1'
  implementation 'io.dscope.camel:camel-persistence-ic4j:1.3.1'
}

Gradle (Kotlin DSL)

dependencies {
  implementation("io.dscope.camel:camel-persistence-core:1.3.1")
  implementation("io.dscope.camel:camel-persistence-jdbc:1.3.1")
}

For Redis backend:

dependencies {
  implementation("io.dscope.camel:camel-persistence-core:1.3.1")
  implementation("io.dscope.camel:camel-persistence-redis:1.3.1")
}

For IC4J / ICP backend:

dependencies {
  implementation("io.dscope.camel:camel-persistence-core:1.3.1")
  implementation("io.dscope.camel:camel-persistence-ic4j:1.3.1")
}

Configuration Properties

Core keys resolved by PersistenceConfiguration.fromProperties(...):

• camel.persistence.enabled (default: false)
• camel.persistence.backend (default: redis; values: redis, jdbc, redis_jdbc, redis_ic4j, ic4j)
• camel.persistence.snapshot-every-events (default: 25)
• camel.persistence.max-replay-events (default: 500)
• camel.persistence.read-batch-size (default: 200)
• camel.persistence.redis.uri (default: redis://localhost:6379)
• camel.persistence.redis.key-prefix (default: camel:state)
• camel.persistence.jdbc.url (default: jdbc:derby:memory:camelPersistence;create=true)
• camel.persistence.jdbc.user (default: empty)
• camel.persistence.jdbc.password (default: empty)
• camel.persistence.icp.replica-url (default: http://127.0.0.1:4943/)
• camel.persistence.icp.canister-id (required for ic4j and redis_ic4j)
• camel.persistence.icp.fetch-root-key (default: true; use false for mainnet)
• camel.persistence.icp.load-idl (default: true)
• camel.persistence.icp.idl-file (default: empty)
• camel.persistence.icp.waiter-timeout (default: 60)
• camel.persistence.icp.waiter-sleep (default: 5)

Quick Start

import io.dscope.camel.persistence.core.FlowStateStore;
import io.dscope.camel.persistence.core.FlowStateStoreFactory;
import io.dscope.camel.persistence.core.PersistenceConfiguration;

import java.util.Properties;

Properties props = new Properties();
props.setProperty("camel.persistence.enabled", "true");
props.setProperty("camel.persistence.backend", "jdbc");
props.setProperty("camel.persistence.jdbc.url", "jdbc:derby:memory:camelPersistence;create=true");

PersistenceConfiguration configuration = PersistenceConfiguration.fromProperties(props);
FlowStateStore store = FlowStateStoreFactory.create(configuration);

// Example read
var rehydrated = store.rehydrate("order", "order-123");

Quick Start (Redis)

import io.dscope.camel.persistence.core.FlowStateStore;
import io.dscope.camel.persistence.core.FlowStateStoreFactory;
import io.dscope.camel.persistence.core.PersistenceConfiguration;

import java.util.Properties;

Properties props = new Properties();
props.setProperty("camel.persistence.enabled", "true");
props.setProperty("camel.persistence.backend", "redis");
props.setProperty("camel.persistence.redis.uri", "redis://localhost:6379");
props.setProperty("camel.persistence.redis.key-prefix", "camel:state");

PersistenceConfiguration configuration = PersistenceConfiguration.fromProperties(props);
FlowStateStore store = FlowStateStoreFactory.create(configuration);

// Example read
var rehydrated = store.rehydrate("order", "order-123");

Quick Start (IC4J / ICP)

import io.dscope.camel.persistence.core.FlowStateStore;
import io.dscope.camel.persistence.core.FlowStateStoreFactory;
import io.dscope.camel.persistence.core.PersistenceConfiguration;

import java.util.Properties;

Properties props = new Properties();
props.setProperty("camel.persistence.enabled", "true");
props.setProperty("camel.persistence.backend", "ic4j");
props.setProperty("camel.persistence.icp.replica-url", "http://127.0.0.1:4943/");
props.setProperty("camel.persistence.icp.canister-id", "<dfx-canister-id>");

PersistenceConfiguration configuration = PersistenceConfiguration.fromProperties(props);
FlowStateStore store = FlowStateStoreFactory.create(configuration);

var rehydrated = store.rehydrate("order", "order-123");

Backend Notes

• Provider resolution uses Java ServiceLoader; backend modules register FlowStateStoreProvider via META-INF/services.
• ic4j uses org.ic4j:ic4j-camel-core:0.8.2 and expects a canister implementing the Candid contract in camel-persistence-ic4j/src/main/icp/persistence.did.
• redis_ic4j uses Redis as a best-effort cache over IC4J/ICP as the durable backend.

Testing

mvn test

Redis contract tests expect Redis reachable at redis://localhost:6379 by default. You can override with:

mvn -Dcamel.persistence.test.redis.uri=redis://<host>:<port> test