o Initial import of JDBC queue.HEADmaster

22 files changed, 1485 insertions, 0 deletions

diff --git a/src/main/java/io/trygvis/activemq/ActiveMqHinter.java b/src/main/java/io/trygvis/activemq/ActiveMqHinter.java
new file mode 100644
index 0000000..f2cfb6e
--- /dev/null
+++ b/src/main/java/io/trygvis/activemq/ActiveMqHinter.java
@@ -0,0 +1,152 @@
+package io.trygvis.activemq;
+
+import io.trygvis.async.QueueController;
+import org.apache.activemq.ActiveMQConnectionFactory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.jms.BytesMessage;
+import javax.jms.JMSException;
+import javax.jms.Message;
+import javax.jms.MessageConsumer;
+import javax.jms.MessageListener;
+import javax.jms.Queue;
+import javax.jms.QueueConnection;
+import javax.jms.QueueSession;
+import javax.jms.TextMessage;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.StringReader;
+import java.nio.charset.Charset;
+import java.sql.SQLException;
+
+import static java.lang.Long.parseLong;
+import static java.lang.System.arraycopy;
+import static java.nio.charset.Charset.forName;
+import static javax.jms.Session.AUTO_ACKNOWLEDGE;
+
+public class ActiveMqHinter implements AutoCloseable {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private final QueueConnection c;
+
+    private static final Charset utf8 = forName("utf-8");
+
+    public ActiveMqHinter(ActiveMQConnectionFactory connectionFactory) throws JMSException {
+        log.info("Connecting to ActiveMQ Broker at {}", connectionFactory.getBrokerURL());
+        c = connectionFactory.createQueueConnection();
+        c.start();
+        log.info("Connected, clientId = {}", c.getClientID());
+    }
+
+    public void createHinter(final QueueController controller) throws JMSException {
+        QueueSession session = c.createQueueSession(false, AUTO_ACKNOWLEDGE);
+        Queue queue = session.createQueue(controller.queue.queue.name);
+        final MessageConsumer consumer = session.createConsumer(queue);
+
+        consumer.setMessageListener(new MessageListener() {
+            @Override
+            public void onMessage(Message message) {
+                if ((message instanceof TextMessage)) {
+                    String body;
+                    try {
+                        TextMessage textMessage = (TextMessage) message;
+                        body = textMessage.getText();
+                    } catch (JMSException e) {
+                        log.warn("Exception while reading body.", e);
+                        throw new RuntimeException("Exception while reading body.", e);
+                    }
+
+                    consumeString(new StringReader(body), controller);
+                } else if (message instanceof BytesMessage) {
+                    final BytesMessage bytesMessage = (BytesMessage) message;
+                    consumeString(new InputStreamReader(new ByteMessageInputStream(bytesMessage), utf8), controller);
+                } else {
+                    throw new RuntimeException("Unsupported message type: " + message.getClass());
+                }
+            }
+        });
+
+        controller.addOnStopListener(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    consumer.close();
+                } catch (JMSException e) {
+                    log.error("Error while closing JMS consumer", e);
+                }
+            }
+        });
+    }
+
+    private void consumeString(Reader reader, QueueController controller) {
+        try {
+            BufferedReader r = new BufferedReader(reader);
+
+            String line = r.readLine();
+
+            while (line != null) {
+                for (String id : line.split(",")) {
+                    controller.hint(parseLong(id.trim()));
+                }
+                line = r.readLine();
+            }
+        } catch (IOException | SQLException e) {
+            log.warn("Could not consume body.", e);
+            throw new RuntimeException("Could not consume body.", e);
+        } catch (NumberFormatException e) {
+            log.warn("Could not consume body.", e);
+            throw e;
+        }
+    }
+
+    public void close() throws JMSException {
+        c.close();
+    }
+
+    private static class ByteMessageInputStream extends InputStream {
+        private final BytesMessage bytesMessage;
+
+        public ByteMessageInputStream(BytesMessage bytesMessage) {
+            this.bytesMessage = bytesMessage;
+        }
+
+        @Override
+        public int read(byte[] b) throws IOException {
+            try {
+                return bytesMessage.readBytes(b);
+            } catch (JMSException e) {
+                throw new IOException(e);
+            }
+        }
+
+        @Override
+        public int read(byte[] out, int off, int len) throws IOException {
+            byte[] b = new byte[len];
+            try {
+                int read = bytesMessage.readBytes(b);
+                if (read == -1) {
+                    return -1;
+                }
+                arraycopy(b, 0, out, off, read);
+                return read;
+            } catch (JMSException e) {
+                throw new IOException(e);
+            }
+        }
+
+        @Override
+        public int read() throws IOException {
+            try {
+                return bytesMessage.readByte();
+            } catch (javax.jms.MessageEOFException e) {
+                return -1;
+            } catch (JMSException e) {
+                throw new IOException(e);
+            }
+        }
+    }
+}
diff --git a/src/main/java/io/trygvis/async/AsyncService.java b/src/main/java/io/trygvis/async/AsyncService.java
new file mode 100755
index 0000000..9332596
--- /dev/null
+++ b/src/main/java/io/trygvis/async/AsyncService.java
@@ -0,0 +1,30 @@
+package io.trygvis.async;
+
+import io.trygvis.queue.Queue;
+import io.trygvis.queue.QueueExecutor;
+import io.trygvis.queue.QueueService;
+import io.trygvis.queue.Task;
+import io.trygvis.queue.TaskEffect;
+
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+
+/**
+ * A simple framework for running tasks.
+ */
+public interface AsyncService {
+
+    QueueController registerQueue(Queue queue, QueueService.TaskExecutionRequest req, TaskEffect processor) throws SQLException;
+
+    QueueExecutor getQueue(String name);
+
+    Task schedule(Queue queue, Date scheduled, List<String> args);
+
+    Task schedule(Queue queue, long parent, Date scheduled, List<String> args);
+
+    /**
+     * Polls for a new state of the execution.
+     */
+    Task update(Task ref);
+}
diff --git a/src/main/java/io/trygvis/async/JdbcAsyncService.java b/src/main/java/io/trygvis/async/JdbcAsyncService.java
new file mode 100644
index 0000000..46f1f30
--- /dev/null
+++ b/src/main/java/io/trygvis/async/JdbcAsyncService.java
@@ -0,0 +1,75 @@
+package io.trygvis.async;
+
+import io.trygvis.queue.QueueExecutor;
+import io.trygvis.queue.QueueService;
+import io.trygvis.queue.QueueSystem;
+import io.trygvis.queue.Task;
+import io.trygvis.queue.TaskEffect;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.lang.System.currentTimeMillis;
+import static java.lang.Thread.sleep;
+
+public class JdbcAsyncService {
+    private final Map<String, QueueController> queues = new HashMap<>();
+
+    private final QueueSystem queueSystem;
+
+    public JdbcAsyncService(QueueSystem queueSystem) {
+        this.queueSystem = queueSystem;
+    }
+
+    public synchronized QueueController registerQueue(QueueExecutor queue, QueueService.TaskExecutionRequest req, TaskEffect processor) {
+        if (queues.containsKey(queue.queue.name)) {
+            throw new IllegalArgumentException("Queue already exist.");
+        }
+
+        QueueController queueController = new QueueController(queueSystem, req, processor, queue);
+
+        queues.put(queue.queue.name, queueController);
+
+        return queueController;
+    }
+
+    public QueueExecutor getQueue(String name) {
+        return getQueueThread(name).queue;
+    }
+
+    public Task await(Connection c, Task task, long timeout) throws SQLException {
+        final long start = currentTimeMillis();
+        final long end = start + timeout;
+
+        while (currentTimeMillis() < end) {
+            task = update(c, task);
+
+            if (task == null) {
+                throw new RuntimeException("The task went away.");
+            }
+
+            try {
+                sleep(100);
+            } catch (InterruptedException e) {
+                // break
+            }
+        }
+
+        return task;
+    }
+
+    public Task update(Connection c, Task ref) throws SQLException {
+        return queueSystem.createTaskDao(c).findById(ref.id());
+    }
+
+    private synchronized QueueController getQueueThread(String name) {
+        QueueController queueController = queues.get(name);
+
+        if (queueController == null) {
+            throw new RuntimeException("No such queue: '" + name + "'.");
+        }
+        return queueController;
+    }
+}
diff --git a/src/main/java/io/trygvis/async/QueueController.java b/src/main/java/io/trygvis/async/QueueController.java
new file mode 100644
index 0000000..a343d42
--- /dev/null
+++ b/src/main/java/io/trygvis/async/QueueController.java
@@ -0,0 +1,201 @@
+package io.trygvis.async;
+
+import io.trygvis.queue.QueueExecutor;
+import io.trygvis.queue.QueueSystem;
+import io.trygvis.queue.SqlEffect;
+import io.trygvis.queue.SqlEffectExecutor;
+import io.trygvis.queue.Task;
+import io.trygvis.queue.TaskEffect;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorCompletionService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+
+import static io.trygvis.queue.QueueExecutor.TaskExecutionResult;
+import static io.trygvis.queue.QueueService.TaskExecutionRequest;
+import static io.trygvis.queue.Task.TaskState.NEW;
+
+public class QueueController {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private final QueueSystem queueSystem;
+
+    private final SqlEffectExecutor sqlEffectExecutor;
+
+    private final TaskEffect taskEffect;
+
+    private final TaskExecutionRequest req;
+
+    public final QueueExecutor queue;
+
+    private boolean shouldRun = true;
+
+    private boolean checkForNewTasks;
+
+    private boolean running;
+
+    private Thread thread;
+
+    private ScheduledThreadPoolExecutor executor;
+
+    private List<Runnable> stopListeners = new ArrayList<>();
+
+    public QueueController(QueueSystem queueSystem, TaskExecutionRequest req, TaskEffect taskEffect, QueueExecutor queue) {
+        this.queueSystem = queueSystem;
+        this.req = req;
+        this.sqlEffectExecutor = queueSystem.sqlEffectExecutor;
+        this.taskEffect = taskEffect;
+        this.queue = queue;
+    }
+
+    public void scheduleAll(final List<Task> tasks) throws InterruptedException {
+        ExecutorCompletionService<TaskExecutionResult> service = new ExecutorCompletionService<>(executor);
+
+        for (final Task task : tasks) {
+            service.submit(new Callable<TaskExecutionResult>() {
+                @Override
+                public TaskExecutionResult call() throws Exception {
+                    return queue.applyTask(taskEffect, task);
+                }
+            });
+        }
+    }
+
+    public void invokeAll(final List<Task> tasks) throws InterruptedException {
+        List<Callable<TaskExecutionResult>> callables = new ArrayList<>(tasks.size());
+        for (final Task task : tasks) {
+            callables.add(new Callable<TaskExecutionResult>() {
+                @Override
+                public TaskExecutionResult call() throws Exception {
+                    return queue.applyTask(taskEffect, task);
+                }
+            });
+        }
+
+        executor.invokeAll(callables);
+    }
+
+    public void hint(final long id) throws SQLException {
+        sqlEffectExecutor.transaction(new SqlEffect.Void() {
+            @Override
+            public void doInConnection(Connection c) throws SQLException {
+                Task task = queueSystem.createTaskDao(c).findById(id);
+
+                try {
+                    scheduleAll(Collections.singletonList(task));
+                } catch (InterruptedException e) {
+                    throw new SQLException(e);
+                }
+            }
+        });
+    }
+
+    public synchronized void addOnStopListener(Runnable runnable) {
+        stopListeners.add(runnable);
+    }
+
+    private class QueueThread implements Runnable {
+        public void run() {
+            while (shouldRun) {
+                List<Task> tasks = null;
+
+                try {
+                    tasks = sqlEffectExecutor.transaction(new SqlEffect<List<Task>>() {
+                        public List<Task> doInConnection(Connection c) throws SQLException {
+                            return queueSystem.createTaskDao(c).findByQueueAndState(queue.queue.name, NEW, req.chunkSize);
+                        }
+                    });
+
+                    log.info("Found {} tasks on queue {}", tasks.size(), queue.queue.name);
+
+                    if (tasks.size() > 0) {
+                        invokeAll(tasks);
+                    }
+                } catch (Throwable e) {
+                    if (shouldRun) {
+                        log.warn("Error while executing tasks.", e);
+                    }
+                }
+
+                // If we found exactly the same number of tasks that we asked for, there is most likely more to go.
+                if (req.continueOnFullChunk && tasks != null && tasks.size() == req.chunkSize) {
+                    log.info("Got a full chunk, continuing directly.");
+                    continue;
+                }
+
+                synchronized (this) {
+                    if (checkForNewTasks) {
+                        log.info("Ping received!");
+                        checkForNewTasks = false;
+                    } else {
+                        try {
+                            wait(req.interval(queue.queue));
+                        } catch (InterruptedException e) {
+                            // ignore
+                        }
+                    }
+                }
+            }
+
+            log.info("Thread for queue {} has stopped.", queue.queue.name);
+            running = false;
+            synchronized (this) {
+                this.notifyAll();
+            }
+        }
+    }
+
+    public synchronized void start(ScheduledThreadPoolExecutor executor) {
+        if (running) {
+            throw new IllegalStateException("Already running");
+        }
+
+        log.info("Starting thread for queue {} with poll interval = {}ms", queue.queue.name, queue.queue.interval);
+
+        running = true;
+        this.executor = executor;
+
+        thread = new Thread(new QueueThread(), "queue: " + queue.queue.name);
+        thread.setDaemon(true);
+        thread.start();
+    }
+
+    public synchronized void stop() {
+        if (!running) {
+            return;
+        }
+
+        log.info("Stopping thread for queue {}", queue.queue.name);
+
+        for (Runnable runnable : stopListeners) {
+            try {
+                runnable.run();
+            } catch (Throwable e) {
+                log.error("Error while running stop listener " + runnable, e);
+            }
+        }
+
+        shouldRun = false;
+
+        // TODO: empty out the currently executing tasks.
+
+        thread.interrupt();
+        while (running) {
+            try {
+                wait(1000);
+            } catch (InterruptedException e) {
+                // continue
+            }
+            thread.interrupt();
+        }
+        thread = null;
+        executor.shutdownNow();
+    }
+}
diff --git a/src/main/java/io/trygvis/async/QueueStats.java b/src/main/java/io/trygvis/async/QueueStats.java
new file mode 100644
index 0000000..8edc720
--- /dev/null
+++ b/src/main/java/io/trygvis/async/QueueStats.java
@@ -0,0 +1,28 @@
+package io.trygvis.async;
+
+public class QueueStats {
+    public final int totalMessageCount;
+    public final int okMessageCount;
+    public final int failedMessageCount;
+    public final int missedMessageCount;
+    public final int scheduledMessageCount;
+
+    public QueueStats(int totalMessageCount, int okMessageCount, int failedMessageCount, int missedMessageCount, int scheduledMessageCount) {
+        this.totalMessageCount = totalMessageCount;
+        this.okMessageCount = okMessageCount;
+        this.failedMessageCount = failedMessageCount;
+        this.missedMessageCount = missedMessageCount;
+        this.scheduledMessageCount = scheduledMessageCount;
+    }
+
+    @Override
+    public String toString() {
+        return "QueueStats{" +
+                "totalMessageCount=" + totalMessageCount +
+                ", okMessageCount=" + okMessageCount +
+                ", failedMessageCount=" + failedMessageCount +
+                ", missedMessageCount=" + missedMessageCount +
+                ", scheduledMessageCount=" + scheduledMessageCount +
+                '}';
+    }
+}
diff --git a/src/main/java/io/trygvis/async/TaskFailureException.java b/src/main/java/io/trygvis/async/TaskFailureException.java
new file mode 100644
index 0000000..7278e17
--- /dev/null
+++ b/src/main/java/io/trygvis/async/TaskFailureException.java
@@ -0,0 +1,7 @@
+package io.trygvis.async;
+
+class TaskFailureException extends RuntimeException {
+    public TaskFailureException(Exception e) {
+        super(e);
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/JdbcQueueService.java b/src/main/java/io/trygvis/queue/JdbcQueueService.java
new file mode 100644
index 0000000..ef0b5bb
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/JdbcQueueService.java
@@ -0,0 +1,55 @@
+package io.trygvis.queue;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class JdbcQueueService {
+
+    private final QueueSystem queueSystem;
+
+    private final SqlEffectExecutor sqlEffectExecutor;
+
+    private final Map<String, QueueExecutor> queues = new HashMap<>();
+
+    JdbcQueueService(QueueSystem queueSystem) {
+        this.queueSystem = queueSystem;
+        this.sqlEffectExecutor = queueSystem.sqlEffectExecutor;
+    }
+
+    public synchronized QueueExecutor getQueue(String name) {
+        QueueExecutor queueExecutor = queues.get(name);
+
+        if (queueExecutor != null) {
+            return queueExecutor;
+        }
+
+        throw new IllegalArgumentException("No such queue: " + name);
+    }
+
+    public synchronized QueueExecutor lookupQueue(Connection c, String name, long interval, boolean autoCreate) throws SQLException {
+        QueueExecutor queueExecutor = queues.get(name);
+
+        if (queueExecutor != null) {
+            return queueExecutor;
+        }
+
+        QueueDao queueDao = queueSystem.createQueueDao(c);
+
+        Queue q = queueDao.findByName(name);
+
+        if (q == null) {
+            if (!autoCreate) {
+                throw new SQLException("No such queue: '" + name + "'.");
+            }
+
+            q = new Queue(name, interval);
+            queueDao.insert(q);
+        }
+
+        queueExecutor = new QueueExecutor(queueSystem, sqlEffectExecutor, q);
+        queues.put(name, queueExecutor);
+        return queueExecutor;
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/Queue.java b/src/main/java/io/trygvis/queue/Queue.java
new file mode 100755
index 0000000..15003f7
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/Queue.java
@@ -0,0 +1,24 @@
+package io.trygvis.queue;
+
+public class Queue {
+
+    public final String name;
+
+    public final long interval;
+
+    public Queue(String name, long interval) {
+        this.name = name;
+        this.interval = interval;
+    }
+
+    public Queue withInterval(int interval) {
+        return new Queue(name, interval);
+    }
+
+    public String toString() {
+        return "Queue{" +
+                "name='" + name + '\'' +
+                ", interval=" + interval +
+                '}';
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/QueueDao.java b/src/main/java/io/trygvis/queue/QueueDao.java
new file mode 100644
index 0000000..2f69e11
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/QueueDao.java
@@ -0,0 +1,45 @@
+package io.trygvis.queue;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class QueueDao {
+
+    private final Connection connection;
+
+    public QueueDao(Connection connection) {
+        this.connection = connection;
+    }
+
+    public Queue findByName(String name) throws SQLException {
+        try (PreparedStatement stmt = connection.prepareStatement("SELECT name, interval FROM queue WHERE name=?")) {
+            stmt.setString(1, name);
+            ResultSet rs = stmt.executeQuery();
+            return rs.next() ? mapRow(rs) : null;
+        }
+    }
+
+    public void insert(Queue q) throws SQLException {
+        try (PreparedStatement stmt = connection.prepareStatement("INSERT INTO queue(name, interval) VALUES(?, ?)")) {
+            int i = 1;
+            stmt.setString(i++, q.name);
+            stmt.setLong(i, q.interval);
+            stmt.executeUpdate();
+        }
+    }
+
+    public void update(Queue q) throws SQLException {
+        try (PreparedStatement stmt = connection.prepareStatement("UPDATE queue SET interval=? WHERE name=?")) {
+            int i = 1;
+            stmt.setLong(i++, q.interval);
+            stmt.setString(i, q.name);
+            stmt.executeUpdate();
+        }
+    }
+
+    public Queue mapRow(ResultSet rs) throws SQLException {
+        return new Queue(rs.getString(1), rs.getLong(2));
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/QueueExecutor.java b/src/main/java/io/trygvis/queue/QueueExecutor.java
new file mode 100644
index 0000000..88e5b46
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/QueueExecutor.java
@@ -0,0 +1,177 @@
+package io.trygvis.queue;
+
+import io.trygvis.async.QueueStats;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+
+import static io.trygvis.queue.QueueExecutor.TaskExecutionResult.*;
+import static io.trygvis.queue.Task.TaskState.NEW;
+
+public class QueueExecutor {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private final QueueSystem queueSystem;
+
+    private final SqlEffectExecutor sqlEffectExecutor;
+
+    public final Queue queue;
+
+    private final Stats stats = new Stats();
+
+    public enum TaskExecutionResult {
+        OK,
+        FAILED,
+        MISSED
+    }
+
+    public QueueExecutor(QueueSystem queueSystem, SqlEffectExecutor sqlEffectExecutor, Queue queue) {
+        this.queueSystem = queueSystem;
+        this.sqlEffectExecutor = sqlEffectExecutor;
+        this.queue = queue;
+    }
+
+    private static class Stats {
+        public int total;
+        public int ok;
+        public int failed;
+        public int scheduled;
+        public int missed;
+
+        public synchronized QueueStats toStats() {
+            return new QueueStats(total, ok, failed, missed, scheduled);
+        }
+    }
+
+    public QueueStats getStats() {
+        return stats.toStats();
+    }
+
+    public void consumeAll(final QueueService.TaskExecutionRequest req, final TaskEffect effect) throws SQLException {
+        log.info("Consuming tasks: request={}", req);
+
+        List<Task> tasks;
+        do {
+            tasks = sqlEffectExecutor.transaction(new SqlEffect<List<Task>>() {
+                @Override
+                public List<Task> doInConnection(Connection c) throws SQLException {
+                    return queueSystem.createTaskDao(c).findByQueueAndState(queue.name, NEW, req.chunkSize);
+                }
+            });
+
+            log.info("Consuming chunk with {} tasks", tasks.size());
+
+            applyTasks(req, effect, tasks);
+        } while (tasks.size() > 0);
+    }
+
+    public void applyTasks(QueueService.TaskExecutionRequest req, TaskEffect effect, List<Task> tasks) {
+        for (Task task : tasks) {
+            TaskExecutionResult result = applyTask(effect, task);
+
+            if (result == FAILED && req.stopOnError) {
+                throw new RuntimeException("Error while executing task, id=" + task.id());
+            }
+        }
+    }
+
+    /**
+     * Executed each task in its own transaction.
+     * <p/>
+     * If the task fails, the status is set to error in a separate transaction.
+     */
+    public TaskExecutionResult applyTask(TaskEffect effect, final Task task) {
+        try {
+            Integer count = sqlEffectExecutor.transaction(new SqlEffect<Integer>() {
+                @Override
+                public Integer doInConnection(Connection c) throws SQLException {
+                    return queueSystem.createTaskDao(c).update(task.markProcessing(), NEW);
+                }
+            });
+
+            if (count == 0) {
+                log.warn("Missed task {}", task.id());
+                synchronized (stats) {
+                    stats.missed++;
+                }
+                return MISSED;
+            }
+
+            log.info("Executing task {}", task.id());
+
+            final List<Task> newTasks = effect.apply(task);
+
+            final Date now = new Date();
+
+            log.info("Executed task {} at {}, newTasks: {}", task.id(), now, newTasks.size());
+
+            sqlEffectExecutor.transaction(new SqlEffect.Void() {
+                @Override
+                public void doInConnection(Connection c) throws SQLException {
+                    for (Task newTask : newTasks) {
+                        schedule(c, newTask);
+                    }
+
+                    queueSystem.createTaskDao(c).update(task.markOk(now));
+                }
+            });
+
+            synchronized (stats) {
+                stats.total++;
+                stats.ok++;
+            }
+
+            return OK;
+        } catch (Exception e) {
+            final Date now = new Date();
+            log.error("Unable to execute task, id=" + task.id(), e);
+
+            synchronized (stats) {
+                stats.total++;
+                stats.failed++;
+            }
+
+            try {
+                sqlEffectExecutor.transaction(new SqlEffect.Void() {
+                    @Override
+                    public void doInConnection(Connection c) throws SQLException {
+                        TaskDao taskDao = queueSystem.createTaskDao(c);
+                        taskDao.update(task.markFailed(now));
+                    }
+                });
+            } catch (SQLException e1) {
+                log.error("Error while marking task as failed.", e1);
+            }
+
+            return FAILED;
+        }
+    }
+
+    public void schedule(Connection c, Task task) throws SQLException {
+        schedule(c, task.queue, task.parent, task.scheduled, task.arguments);
+    }
+
+    public Task schedule(Connection c, Date scheduled, List<String> arguments) throws SQLException {
+        return schedule(c, queue.name, null, scheduled, arguments);
+    }
+
+    public Task schedule(Connection c, long parent, Date scheduled, List<String> arguments) throws SQLException {
+        return schedule(c, queue.name, parent, scheduled, arguments);
+    }
+
+    private Task schedule(Connection c, String queue, Long parent, Date scheduled, List<String> arguments) throws SQLException {
+        TaskDao taskDao = queueSystem.createTaskDao(c);
+
+        long id = taskDao.insert(parent, queue, NEW, scheduled, arguments);
+
+        synchronized (stats) {
+            stats.scheduled++;
+        }
+
+        return new Task(id, parent, queue, NEW, scheduled, null, 0, null, arguments);
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/QueueService.java b/src/main/java/io/trygvis/queue/QueueService.java
new file mode 100644
index 0000000..1c38f1f
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/QueueService.java
@@ -0,0 +1,54 @@
+package io.trygvis.queue;
+
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+
+public interface QueueService {
+    QueueExecutor getQueue(String name, int interval, boolean autoCreate) throws SQLException;
+
+    void schedule(Queue queue, Date scheduled, List<String> arguments) throws SQLException;
+
+    public static class TaskExecutionRequest {
+        public final long chunkSize;
+        public final boolean stopOnError;
+        public final Long interval;
+        public final boolean continueOnFullChunk;
+        // TODO: saveExceptions
+
+        public TaskExecutionRequest(long chunkSize, boolean stopOnError) {
+            this(chunkSize, stopOnError, null, true);
+        }
+
+        private TaskExecutionRequest(long chunkSize, boolean stopOnError, Long interval, boolean continueOnFullChunk) {
+            this.chunkSize = chunkSize;
+            this.stopOnError = stopOnError;
+            this.interval = interval;
+            this.continueOnFullChunk = continueOnFullChunk;
+        }
+
+        public TaskExecutionRequest interval(long interval) {
+            return new TaskExecutionRequest(chunkSize, stopOnError, interval, continueOnFullChunk);
+        }
+
+        public TaskExecutionRequest continueOnFullChunk(boolean continueOnFullChunk) {
+            return new TaskExecutionRequest(chunkSize, stopOnError, interval, continueOnFullChunk);
+        }
+
+        @Override
+        public String toString() {
+            return "TaskExecutionRequest{" +
+                    "chunkSize=" + chunkSize +
+                    ", stopOnError=" + stopOnError +
+                    '}';
+        }
+
+        public long interval(Queue queue) {
+            if (interval != null) {
+                return interval;
+            }
+
+            return queue.interval;
+        }
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/QueueStats.java b/src/main/java/io/trygvis/queue/QueueStats.java
new file mode 100644
index 0000000..5b048b3
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/QueueStats.java
@@ -0,0 +1,20 @@
+package io.trygvis.queue;
+
+import java.util.EnumMap;
+
+public class QueueStats {
+    public final String name;
+    public final long totalTaskCount;
+    public final EnumMap<Task.TaskState, Long> states;
+
+    public QueueStats(String name, EnumMap<Task.TaskState, Long> states) {
+        this.name = name;
+        this.states = states;
+
+        long c = 0;
+        for (Long l : states.values()) {
+            c += l;
+        }
+        this.totalTaskCount = c;
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/QueueSystem.java b/src/main/java/io/trygvis/queue/QueueSystem.java
new file mode 100644
index 0000000..5954526
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/QueueSystem.java
@@ -0,0 +1,61 @@
+package io.trygvis.queue;
+
+import io.trygvis.async.JdbcAsyncService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.SQLException;
+
+public class QueueSystem {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    public final SqlEffectExecutor sqlEffectExecutor;
+
+    private final JdbcQueueService queueService;
+
+    private QueueSystem(SqlEffectExecutor sqlEffectExecutor) throws SQLException {
+        sqlEffectExecutor.transaction(new SqlEffect.Void() {
+            @Override
+            public void doInConnection(Connection c) throws SQLException {
+                if (c.getAutoCommit()) {
+                    throw new SQLException("The connection cannot be in auto-commit mode.");
+                }
+
+                DatabaseMetaData metaData = c.getMetaData();
+                String productName = metaData.getDatabaseProductName();
+                String productVersion = metaData.getDatabaseProductVersion();
+
+                log.info("productName = " + productName);
+                log.info("productVersion = " + productVersion);
+            }
+        });
+
+        this.sqlEffectExecutor = sqlEffectExecutor;
+        queueService = new JdbcQueueService(this);
+    }
+
+    /**
+     * Initializes the queue system. Use this as the first thing do as it will validate the database.
+     */
+    public static QueueSystem initialize(SqlEffectExecutor sqlEffectExecutor) throws SQLException {
+        return new QueueSystem(sqlEffectExecutor);
+    }
+
+    public JdbcQueueService createQueueService() {
+        return queueService;
+    }
+
+    public QueueDao createQueueDao(Connection c) {
+        return new QueueDao(c);
+    }
+
+    public TaskDao createTaskDao(Connection c) {
+        return new TaskDao(c);
+    }
+
+    public JdbcAsyncService createAsyncService() {
+        return new JdbcAsyncService(this);
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/SqlEffect.java b/src/main/java/io/trygvis/queue/SqlEffect.java
new file mode 100644
index 0000000..7864bcd
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/SqlEffect.java
@@ -0,0 +1,12 @@
+package io.trygvis.queue;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+public interface SqlEffect<A> {
+    A doInConnection(Connection c) throws SQLException;
+
+    interface Void {
+        void doInConnection(Connection c) throws SQLException;
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/SqlEffectExecutor.java b/src/main/java/io/trygvis/queue/SqlEffectExecutor.java
new file mode 100644
index 0000000..92802da
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/SqlEffectExecutor.java
@@ -0,0 +1,50 @@
+package io.trygvis.queue;
+
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.SQLException;
+
+public class SqlEffectExecutor {
+
+    private final DataSource dataSource;
+
+    public SqlEffectExecutor(DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    public <A> A transaction(SqlEffect<A> effect) throws SQLException {
+//        int pid;
+
+        try (Connection c = dataSource.getConnection()) {
+//            pid = getPid(c);
+//            System.out.println("pid = " + pid);
+
+            boolean ok = false;
+            try {
+                A a = effect.doInConnection(c);
+                c.commit();
+                ok = true;
+                return a;
+            } finally {
+//                System.out.println("Closing, pid = " + pid);
+                if (!ok) {
+                    try {
+                        c.rollback();
+                    } catch (SQLException e) {
+                        // ignore
+                    }
+                }
+            }
+        }
+    }
+
+    public void transaction(final SqlEffect.Void effect) throws SQLException {
+        transaction(new SqlEffect<Object>() {
+            @Override
+            public Object doInConnection(Connection c) throws SQLException {
+                effect.doInConnection(c);
+                return null;
+            }
+        });
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/Task.java b/src/main/java/io/trygvis/queue/Task.java
new file mode 100755
index 0000000..8038050
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/Task.java
@@ -0,0 +1,117 @@
+package io.trygvis.queue;
+
+import java.util.Date;
+import java.util.List;
+
+import static io.trygvis.queue.Task.TaskState.*;
+import static java.util.Arrays.asList;
+
+public class Task {
+
+    public enum TaskState {
+        NEW,
+        PROCESSING,
+        OK,
+        FAILED
+    }
+
+    private final long id;
+
+    public final Long parent;
+
+    public final String queue;
+
+    public final TaskState state;
+
+    public final Date scheduled;
+
+    public final Date lastRun;
+
+    public final int runCount;
+
+    public final Date completed;
+
+    public final List<String> arguments;
+
+    public Task(long id, Long parent, String queue, TaskState state, Date scheduled, Date lastRun, int runCount, Date completed, List<String> arguments) {
+        this.id = id;
+        this.parent = parent;
+        this.queue = queue;
+        this.state = state;
+        this.scheduled = scheduled;
+        this.lastRun = lastRun;
+        this.runCount = runCount;
+        this.completed = completed;
+
+        this.arguments = arguments;
+    }
+
+    public Task markProcessing() {
+        return new Task(id, parent, queue, PROCESSING, scheduled, new Date(), runCount + 1, completed, arguments);
+    }
+
+    public Task markOk(Date completed) {
+        return new Task(id, parent, queue, OK, scheduled, lastRun, runCount, completed, arguments);
+    }
+
+    public Task markFailed(Date now) {
+        return new Task(id, parent, queue, FAILED, scheduled, lastRun, runCount, completed, arguments);
+    }
+
+    public String toString() {
+        return "Task{" +
+                "id=" + id +
+                ", parent=" + parent +
+                ", queue=" + queue +
+                ", state=" + state +
+                ", scheduled=" + scheduled +
+                ", lastRun=" + lastRun +
+                ", runCount=" + runCount +
+                ", completed=" + completed +
+                ", arguments='" + arguments + '\'' +
+                '}';
+    }
+
+    public long id() {
+        if (id == 0) {
+            throw new RuntimeException("This task has not been persisted yet.");
+        }
+
+        return id;
+    }
+
+    public boolean isDone() {
+        return completed != null;
+    }
+
+    public Task childTask(String queue, Date scheduled, String... arguments) {
+        return new Task(0, id(), queue, NEW, scheduled, null, 0, null, asList(arguments));
+    }
+
+    public static Task newTask(String queue, Date scheduled, String... arguments) {
+        return new Task(0, null, queue, NEW, scheduled, null, 0, null, asList(arguments));
+    }
+
+    public static Task newTask(String queue, Date scheduled, List<String> arguments) {
+        return new Task(0, null, queue, NEW, scheduled, null, 0, null, arguments);
+    }
+
+    public static List<String> stringToArguments(String arguments) {
+        return asList(arguments.split(","));
+    }
+
+    public static String argumentsToString(List<String> arguments) {
+        StringBuilder builder = new StringBuilder();
+        for (int i = 0, argumentsLength = arguments.size(); i < argumentsLength; i++) {
+            String argument = arguments.get(i);
+            if (argument.contains(",")) {
+                throw new RuntimeException("The argument string can't contain a comma.");
+            }
+            if (i > 0) {
+                builder.append(',');
+            }
+            builder.append(argument);
+        }
+        return builder.toString();
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/TaskDao.java b/src/main/java/io/trygvis/queue/TaskDao.java
new file mode 100644
index 0000000..365b44b
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/TaskDao.java
@@ -0,0 +1,148 @@
+package io.trygvis.queue;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Timestamp;
+import java.sql.Types;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Date;
+import java.util.EnumMap;
+import java.util.List;
+
+import static io.trygvis.queue.Task.*;
+
+public class TaskDao {
+
+    private final Connection c;
+
+    public static final String fields = "id, parent, queue, state, scheduled, last_run, run_count, completed, arguments";
+
+    TaskDao(Connection c) {
+        this.c = c;
+    }
+
+    public long insert(Long parent, String queue, TaskState state, Date scheduled, List<String> arguments) throws SQLException {
+        String sql = "INSERT INTO task(id, parent, run_count, queue, state, scheduled, arguments) " +
+                "VALUES(nextval('task_seq'), ?, 0, ?, ?, ?, ?)";
+        try (PreparedStatement stmt = c.prepareStatement(sql)) {
+            int i = 1;
+            if (parent == null) {
+                stmt.setNull(i++, Types.BIGINT);
+            } else {
+                stmt.setLong(i++, parent);
+            }
+            stmt.setString(i++, queue);
+            stmt.setString(i++, state.name());
+            stmt.setTimestamp(i++, new Timestamp(scheduled.getTime()));
+            stmt.setString(i, argumentsToString(arguments));
+            stmt.executeUpdate();
+        }
+        try (PreparedStatement stmt = c.prepareStatement("SELECT currval('task_seq')")) {
+            ResultSet rs = stmt.executeQuery();
+            rs.next();
+            return rs.getLong(1);
+        }
+    }
+
+    public Task findById(long id) throws SQLException {
+        try (PreparedStatement stmt = c.prepareStatement("SELECT " + fields + " FROM task WHERE id=?")) {
+            stmt.setLong(1, id);
+            ResultSet rs = stmt.executeQuery();
+            return rs.next() ? mapRow(rs) : null;
+        }
+    }
+
+    public List<Task> findByQueueAndState(String queue, TaskState state, long limit) throws SQLException {
+        try (PreparedStatement stmt = c.prepareStatement("SELECT " + fields + " FROM task WHERE queue=? AND state=? LIMIT ?")) {
+            int i = 1;
+            stmt.setString(i++, queue);
+            stmt.setString(i++, state.name());
+            stmt.setLong(i, limit);
+            ResultSet rs = stmt.executeQuery();
+            List<Task> list = new ArrayList<>();
+            while (rs.next()) {
+                list.add(mapRow(rs));
+            }
+            return list;
+        }
+    }
+
+    public QueueStats findQueueStatsByName(String queue) throws SQLException {
+        try (PreparedStatement stmt = c.prepareStatement("SELECT state, COUNT(id) FROM task WHERE queue=? GROUP BY state")) {
+            int i = 1;
+            stmt.setString(i, queue);
+            ResultSet rs = stmt.executeQuery();
+            EnumMap<TaskState, Long> states = new EnumMap<>(TaskState.class);
+            while (rs.next()) {
+                states.put(TaskState.valueOf(rs.getString(1)), rs.getLong(2));
+            }
+            return new QueueStats(queue, states);
+        }
+    }
+
+    public int update(Task task) throws SQLException {
+        return update(task, null);
+    }
+
+    public int update(Task task, TaskState state) throws SQLException {
+        String sql = "UPDATE task SET state=?, scheduled=?, last_run=?, run_count=?, completed=? WHERE id=?";
+
+        if (state != null) {
+            sql += " AND state=?";
+        }
+
+        try (PreparedStatement stmt = c.prepareStatement(sql)) {
+            int i = 1;
+            stmt.setString(i++, task.state.name());
+            stmt.setTimestamp(i++, new Timestamp(task.scheduled.getTime()));
+            setTimestamp(stmt, i++, task.lastRun);
+            stmt.setInt(i++, task.runCount);
+            setTimestamp(stmt, i++, task.completed);
+            stmt.setLong(i++, task.id());
+            if (state != null) {
+                stmt.setString(i, state.name());
+            }
+            return stmt.executeUpdate();
+        }
+    }
+
+    public void setState(Task task, TaskState state) throws SQLException {
+        try (PreparedStatement stmt = c.prepareStatement("UPDATE task SET state=? WHERE id = ?")) {
+            int i = 1;
+            stmt.setString(i++, state.name());
+            stmt.setLong(i, task.id());
+            stmt.executeUpdate();
+        }
+    }
+
+    private static void setTimestamp(PreparedStatement stmt, int parameterIndex, Date date) throws SQLException {
+        if (date == null) {
+            stmt.setNull(parameterIndex, Types.TIMESTAMP);
+        } else {
+            stmt.setTimestamp(parameterIndex, new Timestamp(date.getTime()));
+        }
+    }
+
+    public Task mapRow(ResultSet rs) throws SQLException {
+        String arguments = rs.getString(9);
+        int i = 1;
+        return new Task(
+                rs.getLong(i++),
+                rs.getLong(i++),
+                rs.getString(i++),
+                TaskState.valueOf(rs.getString(i++)),
+                rs.getTimestamp(i++),
+                rs.getTimestamp(i++),
+                rs.getInt(i++),
+                rs.getTimestamp(i),
+                arguments != null ? stringToArguments(arguments) : Collections.<String>emptyList());
+    }
+
+    public void rollback() throws SQLException {
+        c.rollback();
+        c.close();
+    }
+}
diff --git a/src/main/java/io/trygvis/queue/TaskEffect.java b/src/main/java/io/trygvis/queue/TaskEffect.java
new file mode 100644
index 0000000..186797f
--- /dev/null
+++ b/src/main/java/io/trygvis/queue/TaskEffect.java
@@ -0,0 +1,7 @@
+package io.trygvis.queue;
+
+import java.util.List;
+
+public interface TaskEffect {
+    List<Task> apply(Task task) throws Exception;
+}
diff --git a/src/main/java/io/trygvis/spring/DefaultConfig.java b/src/main/java/io/trygvis/spring/DefaultConfig.java
new file mode 100644
index 0000000..6890d58
--- /dev/null
+++ b/src/main/java/io/trygvis/spring/DefaultConfig.java
@@ -0,0 +1,31 @@
+package io.trygvis.spring;
+
+import io.trygvis.async.AsyncService;
+import io.trygvis.queue.SqlEffectExecutor;
+import io.trygvis.queue.QueueService;
+import io.trygvis.queue.QueueSystem;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+import javax.sql.DataSource;
+import java.sql.SQLException;
+
+@Configuration
+public class DefaultConfig {
+
+    @Bean
+    public QueueSystem queueSystem(DataSource ds) throws SQLException {
+        return QueueSystem.initialize(new SqlEffectExecutor(ds));
+    }
+
+    @Bean
+    public AsyncService asyncService(QueueSystem queueSystem, JdbcTemplate jdbcTemplate) {
+        return new SpringJdbcAsyncService(queueSystem, jdbcTemplate);
+    }
+
+    @Bean
+    public QueueService queueService(QueueSystem queueSystem, JdbcTemplate jdbcTemplate) {
+        return new SpringQueueService(queueSystem, jdbcTemplate);
+    }
+}
diff --git a/src/main/java/io/trygvis/spring/SpringJdbcAsyncService.java b/src/main/java/io/trygvis/spring/SpringJdbcAsyncService.java
new file mode 100644
index 0000000..12dc71e
--- /dev/null
+++ b/src/main/java/io/trygvis/spring/SpringJdbcAsyncService.java
@@ -0,0 +1,110 @@
+package io.trygvis.spring;
+
+import io.trygvis.async.AsyncService;
+import io.trygvis.async.JdbcAsyncService;
+import io.trygvis.async.QueueController;
+import io.trygvis.queue.SqlEffect;
+import io.trygvis.queue.JdbcQueueService;
+import io.trygvis.queue.Queue;
+import io.trygvis.queue.QueueExecutor;
+import io.trygvis.queue.QueueService;
+import io.trygvis.queue.QueueSystem;
+import io.trygvis.queue.Task;
+import io.trygvis.queue.TaskEffect;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.jdbc.core.ConnectionCallback;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationAdapter;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+
+import static org.springframework.transaction.annotation.Propagation.REQUIRED;
+import static org.springframework.transaction.support.TransactionSynchronizationManager.registerSynchronization;
+
+public class SpringJdbcAsyncService implements AsyncService {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private final ScheduledThreadPoolExecutor executor;
+
+    private final JdbcTemplate jdbcTemplate;
+
+    private final JdbcAsyncService jdbcAsyncService;
+
+    private final JdbcQueueService queueService;
+
+    private final QueueSystem queueSystem;
+
+    public SpringJdbcAsyncService(QueueSystem queueSystem, JdbcTemplate jdbcTemplate) {
+        this.queueSystem = queueSystem;
+        this.jdbcTemplate = jdbcTemplate;
+        jdbcAsyncService = new JdbcAsyncService(queueSystem);
+        queueService = queueSystem.createQueueService();
+        executor = new ScheduledThreadPoolExecutor(10, Executors.defaultThreadFactory());
+    }
+
+    @Transactional(propagation = REQUIRED)
+    public QueueController registerQueue(final Queue queue, final QueueService.TaskExecutionRequest req, final TaskEffect processor) throws SQLException {
+        QueueExecutor queueExecutor = queueSystem.sqlEffectExecutor.transaction(new SqlEffect<QueueExecutor>() {
+            @Override
+            public QueueExecutor doInConnection(Connection c) throws SQLException {
+                return queueService.lookupQueue(c, queue.name, queue.interval, true);
+            }
+        });
+
+        final QueueController queueController = jdbcAsyncService.registerQueue(queueExecutor, req, processor);
+
+        registerSynchronization(new TransactionSynchronizationAdapter() {
+            public void afterCompletion(int status) {
+                log.info("Transaction completed with status = {}", status);
+                if (status == TransactionSynchronization.STATUS_COMMITTED) {
+                    queueController.start(executor);
+                }
+            }
+        });
+
+        return queueController;
+    }
+
+    public QueueExecutor getQueue(String name) {
+        return jdbcAsyncService.getQueue(name);
+    }
+
+    @Transactional(propagation = REQUIRED)
+    public Task schedule(final Queue queue, final Date scheduled, final List<String> args) {
+        return jdbcTemplate.execute(new ConnectionCallback<Task>() {
+            @Override
+            public Task doInConnection(Connection c) throws SQLException {
+                QueueExecutor queueExecutor = queueService.getQueue(queue.name);
+                return queueExecutor.schedule(c, scheduled, args);
+            }
+        });
+    }
+
+    public Task schedule(final Queue queue, final long parent, final Date scheduled, final List<String> args) {
+        return jdbcTemplate.execute(new ConnectionCallback<Task>() {
+            @Override
+            public Task doInConnection(Connection c) throws SQLException {
+                QueueExecutor queueExecutor = queueService.getQueue(queue.name);
+                return queueExecutor.schedule(c, parent, scheduled, args);
+            }
+        });
+    }
+
+    @Transactional(readOnly = true)
+    public Task update(final Task ref) {
+        return jdbcTemplate.execute(new ConnectionCallback<Task>() {
+            @Override
+            public Task doInConnection(Connection c) throws SQLException {
+                return jdbcAsyncService.update(c, ref);
+            }
+        });
+    }
+}
diff --git a/src/main/java/io/trygvis/spring/SpringQueueService.java b/src/main/java/io/trygvis/spring/SpringQueueService.java
new file mode 100644
index 0000000..2027ab5
--- /dev/null
+++ b/src/main/java/io/trygvis/spring/SpringQueueService.java
@@ -0,0 +1,49 @@
+package io.trygvis.spring;
+
+import io.trygvis.queue.JdbcQueueService;
+import io.trygvis.queue.Queue;
+import io.trygvis.queue.QueueExecutor;
+import io.trygvis.queue.QueueService;
+import io.trygvis.queue.QueueSystem;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.core.ConnectionCallback;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Date;
+import java.util.List;
+
+public class SpringQueueService implements QueueService {
+
+    public final JdbcTemplate jdbcTemplate;
+
+    public JdbcQueueService queueService;
+
+    public SpringQueueService(QueueSystem queueSystem, JdbcTemplate jdbcTemplate) {
+        this.jdbcTemplate = jdbcTemplate;
+        this.queueService = queueSystem.createQueueService();
+    }
+
+    @Transactional
+    public QueueExecutor getQueue(final String name, final int interval, final boolean autoCreate) throws SQLException {
+        return jdbcTemplate.execute(new ConnectionCallback<QueueExecutor>() {
+            @Override
+            public QueueExecutor doInConnection(Connection c) throws SQLException, DataAccessException {
+                return queueService.lookupQueue(c, name, interval, autoCreate);
+            }
+        });
+    }
+
+    @Transactional
+    public void schedule(final Queue queue, final Date scheduled, final List<String> arguments) throws SQLException {
+        jdbcTemplate.execute(new ConnectionCallback<Object>() {
+            @Override
+            public Object doInConnection(Connection c) throws SQLException, DataAccessException {
+                queueService.getQueue(queue.name).schedule(c, scheduled, arguments);
+                return null;
+            }
+        });
+    }
+}
diff --git a/src/main/resources/create-postgresql.sql b/src/main/resources/create-postgresql.sql
new file mode 100644
index 0000000..a0739c2
--- /dev/null
+++ b/src/main/resources/create-postgresql.sql
@@ -0,0 +1,32 @@
+BEGIN;
+
+DROP TABLE IF EXISTS task;
+DROP TABLE IF EXISTS queue;
+DROP SEQUENCE IF EXISTS task_seq;
+
+CREATE TABLE queue (
+  name     VARCHAR(100) NOT NULL,
+  interval INTEGER      NOT NULL,
+  CONSTRAINT pk_queue PRIMARY KEY (name)
+);
+
+CREATE TABLE task (
+  id        BIGINT       NOT NULL,
+  parent    BIGINT,
+  queue     VARCHAR(100) NOT NULL,
+  state     VARCHAR(10)  NOT NULL,
+  scheduled TIMESTAMP    NOT NULL,
+  last_run  TIMESTAMP,
+  run_count INT          NOT NULL,
+  completed TIMESTAMP,
+  arguments VARCHAR(100),
+  CONSTRAINT pk_task PRIMARY KEY (id),
+  CONSTRAINT fk_task__queue FOREIGN KEY (queue) REFERENCES queue (name),
+  CONSTRAINT fk_task__parent FOREIGN KEY (parent) REFERENCES task (id)
+);
+
+CREATE INDEX ix_task__queue__state ON task (queue, state);
+
+CREATE SEQUENCE task_seq;
+
+COMMIT;