public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("Pull Subscription using primitive Expires In", args, Usage) .DefaultStream("fetch-uc-stream") .DefaultSubject("fetch-uc-subject") .DefaultDurable("fetch-uc-durable") .DefaultCount(15) .Build(); try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // Use the utility to create a stream stored in memory. JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, helper.Subject); // Create our JetStream context. IJetStream js = c.CreateJetStreamContext(); // Build our consumer configuration and subscription options. // make sure the ack wait is sufficient to handle the reading and processing of the batch. // Durable is REQUIRED for pull based subscriptions ConsumerConfiguration cc = ConsumerConfiguration.Builder() .WithAckWait(2500) .Build(); PullSubscribeOptions pullOptions = PullSubscribeOptions.Builder() .WithDurable(helper.Durable) // required .WithConfiguration(cc) .Build(); // 0.1 Initialize. subscription // 0.2 Flush outgoing communication with/to the server, useful when app is both JsUtils.Publishing and subscribing. Console.WriteLine("\n----------\n0. Initialize the subscription and pull."); IJetStreamPullSubscription sub = js.PullSubscribe(helper.Subject, pullOptions); c.Flush(1000); // 1. Fetch, but there are no messages yet. // - Read the messages, get them all (0) Console.WriteLine("----------\n1. There are no messages yet"); IList <Msg> messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 0 total messages, we received: " + messages.Count); // 2. Publish 10 messages // - Fetch messages, get 10 Console.WriteLine("----------\n2. Publish 10 which satisfies the batch"); JsUtils.Publish(js, helper.Subject, "A", 10); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 3. Publish 20 messages // - Fetch messages, only get 10 Console.WriteLine("----------\n3. Publish 20 which is larger than the batch size."); JsUtils.Publish(js, helper.Subject, "B", 20); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 4. There are still messages left from the last // - Fetch messages, get 10 Console.WriteLine("----------\n4. Get the rest of the JsUtils.Publish."); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 5. Publish 5 messages // - Fetch messages, get 5 // - Since there are less than batch size we only get what the server has. Console.WriteLine("----------\n5. Publish 5 which is less than batch size."); JsUtils.Publish(js, helper.Subject, "C", 5); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 5 total messages, we received: " + messages.Count); // 6. Publish 15 messages // - Fetch messages, only get 10 Console.WriteLine("----------\n6. Publish 15 which is more than the batch size."); JsUtils.Publish(js, helper.Subject, "D", 15); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 7. There are 5 messages left // - Fetch messages, only get 5 Console.WriteLine("----------\n7. There are 5 messages left."); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 5 messages, we received: " + messages.Count); // 8. Read but don't ack. // - Fetch messages, get 10, but either take too long to ack them or don't ack them Console.WriteLine("----------\n8. Fetch but don't ack."); JsUtils.Publish(js, helper.Subject, "E", 10); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); Console.WriteLine("We should have received 10 message, we received: " + messages.Count); Thread.Sleep(3000); // longer than the ackWait // 9. Fetch messages, // - get the 10 messages we didn't ack Console.WriteLine("----------\n9. Fetch, get the messages we did not ack."); messages = sub.Fetch(10, 3000); JsUtils.Report(messages); foreach (Msg m in messages) { m.Ack(); } Console.WriteLine("We should have received 10 message, we received: " + messages.Count); Console.WriteLine("----------\n"); // delete the stream since we are done with it. jsm.DeleteStream(helper.Stream); } } catch (Exception ex) { helper.ReportException(ex); } }
public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("JetStream Manage Streams", args, Usage) .DefaultStream("manage-stream-") .DefaultSubject("manage-subject-") .Build(); string stream1 = helper.Stream + "1"; string stream2 = helper.Stream + "2"; string subject1 = helper.Subject + "1"; string subject2 = helper.Subject + "2"; string subject3 = helper.Subject + "3"; string subject4 = helper.Subject + "4"; try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // we want to be able to completely create and delete the streams // so don't want to work with existing streams JsUtils.ExitIfStreamExists(jsm, stream1); JsUtils.ExitIfStreamExists(jsm, stream2); // 1. Create (add) a stream with a subject Console.WriteLine("\n----------\n1. Configure And Add Stream 1"); StreamConfiguration streamConfig = StreamConfiguration.Builder() .WithName(stream1) .WithSubjects(subject1) // .WithRetentionPolicy(...) // .WithMaxConsumers(...) // .WithMaxBytes(...) // .WithMaxAge(...) // .WithMaxMsgSize(...) .WithStorageType(StorageType.Memory) // .WithReplicas(...) // .WithNoAck(...) // .WithTemplateOwner(...) // .WithDiscardPolicy(...) .Build(); StreamInfo streamInfo = jsm.AddStream(streamConfig); PrintUtils.PrintStreamInfo(streamInfo); // 2. Update stream, in this case add a subject // Thre are very few properties that can actually // - StreamConfiguration is immutable once created // - but the builder can help with that. Console.WriteLine("----------\n2. Update Stream 1"); streamConfig = StreamConfiguration.Builder(streamInfo.Config) .AddSubjects(subject2).Build(); streamInfo = jsm.UpdateStream(streamConfig); PrintUtils.PrintStreamInfo(streamInfo); // 3. Create (add) another stream with 2 subjects Console.WriteLine("----------\n3. Configure And Add Stream 2"); streamConfig = StreamConfiguration.Builder() .WithName(stream2) .WithSubjects(subject3, subject4) .WithStorageType(StorageType.Memory) .Build(); streamInfo = jsm.AddStream(streamConfig); PrintUtils.PrintStreamInfo(streamInfo); // 4. Get information on streams // 4.0 publish some message for more interesting stream state information // - SUBJECT1 is associated with STREAM1 // 4.1 getStreamInfo on a specific stream // 4.2 get a list of all streams // 4.3 get a list of StreamInfo's for all streams Console.WriteLine("----------\n4.1 getStreamInfo"); JsUtils.Publish(c, subject1, 5); streamInfo = jsm.GetStreamInfo(stream1); PrintUtils.PrintStreamInfo(streamInfo); Console.WriteLine("----------\n4.2 getStreamNames"); IList <String> streamNames = jsm.GetStreamNames(); PrintUtils.PrintObject(streamNames); Console.WriteLine("----------\n4.3 getStreams"); IList <StreamInfo> streamInfos = jsm.GetStreams(); PrintUtils.PrintStreamInfoList(streamInfos); // 5. Purge a stream of it's messages Console.WriteLine("----------\n5. Purge stream"); PurgeResponse purgeResponse = jsm.PurgeStream(stream1); PrintUtils.PrintObject(purgeResponse); // 6. Delete the streams // Subsequent calls to getStreamInfo, deleteStream or purgeStream // will throw a JetStreamApiException "stream not found [10059]" Console.WriteLine("----------\n6. Delete streams"); jsm.DeleteStream(stream1); jsm.DeleteStream(stream2); // 7. Try to delete the consumer again and get the exception Console.WriteLine("----------\n7. Delete stream again"); try { jsm.DeleteStream(stream1); } catch (NATSJetStreamException e) { Console.WriteLine($"Exception was: '{e.ErrorDescription}'"); } Console.WriteLine("----------\n"); } } catch (Exception ex) { helper.ReportException(ex); } }
public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("NATS JetStream Push Subscribe Bind Durable", args, Usage) .DefaultStream("fs-stream") .DefaultSubject("fs-subject") .Build(); string subjectWild = helper.Subject + ".*"; string subjectA = helper.Subject + ".A"; string subjectB = helper.Subject + ".B"; try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // Use the utility to create a stream stored in memory. JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, subjectWild); // Create our JetStream context to publish and receive JetStream messages. IJetStream js = c.CreateJetStreamContext(); JsUtils.Publish(js, subjectA, 1); JsUtils.Publish(js, subjectB, 1); JsUtils.Publish(js, subjectA, 1); JsUtils.Publish(js, subjectB, 1); // 1. create a subscription that subscribes to the wildcard subject ConsumerConfiguration cc = ConsumerConfiguration.Builder() .WithAckPolicy(AckPolicy.None) // don't want to worry about acking messages. .Build(); PushSubscribeOptions pso = PushSubscribeOptions.Builder() .WithConfiguration(cc) .Build(); IJetStreamPushSyncSubscription sub = js.PushSubscribeSync(subjectWild, pso); c.Flush(5000); Msg m = sub.NextMessage(1000); Console.WriteLine("\n1A1. Message should be from '" + subjectA + "', Sequence #1. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); m = sub.NextMessage(1000); Console.WriteLine("1B2. Message should be from '" + subjectB + "', Sequence #2. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); m = sub.NextMessage(1000); Console.WriteLine("1A3. Message should be from '" + subjectA + "', Sequence #3. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); m = sub.NextMessage(1000); Console.WriteLine("1B4. Message should be from '" + subjectB + "', Sequence #4. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); // 2. create a subscription that subscribes only to the A subject cc = ConsumerConfiguration.Builder() .WithAckPolicy(AckPolicy.None) // don't want to worry about acking messages. .WithFilterSubject(subjectA) .Build(); pso = PushSubscribeOptions.Builder() .WithConfiguration(cc) .Build(); sub = js.PushSubscribeSync(subjectWild, pso); c.Flush(5000); m = sub.NextMessage(1000); Console.WriteLine("\n2A1. Message should be from '" + subjectA + "', Sequence #1. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); m = sub.NextMessage(1000); Console.WriteLine("2A3. Message should be from '" + subjectA + "', Sequence #3. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); try { sub.NextMessage(1000); Console.WriteLine("2x. NOPE! Should not have gotten here"); } catch (NATSTimeoutException) // timeout means there are no messages available { Console.WriteLine("2x. There was no message available."); } // 3. create a subscription that subscribes only to the A subject cc = ConsumerConfiguration.Builder() .WithAckPolicy(AckPolicy.None) // don't want to worry about acking messages. .WithFilterSubject(subjectB) .Build(); pso = PushSubscribeOptions.Builder() .WithConfiguration(cc) .Build(); sub = js.PushSubscribeSync(subjectWild, pso); c.Flush(5000); m = sub.NextMessage(1000); Console.WriteLine("\n3A2. Message should be from '" + subjectB + "', Sequence #2. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); m = sub.NextMessage(1000); Console.WriteLine("3A4. Message should be from '" + subjectB + "', Sequence #4. " + "It was: '" + m.Subject + "', Seq #" + m.MetaData.StreamSequence); try { sub.NextMessage(1000); Console.WriteLine("3x. NOPE! Should not have gotten here"); } catch (NATSTimeoutException) // timeout means there are no messages available { Console.WriteLine("3x. There was no message available."); } Console.WriteLine(); // delete the stream since we are done with it. jsm.DeleteStream(helper.Stream); } } catch (Exception ex) { helper.ReportException(ex); } }
public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("Pull Subscription using primitive Expires In, Use Cases", args, Usage) .DefaultStream("expires-in-uc-stream") .DefaultSubject("expires-in-uc-subject") .DefaultDurable("expires-in-uc-durable") .Build(); try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // Use the utility to create a stream stored in memory. JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, helper.Subject); // Create our JetStream context. IJetStream js = c.CreateJetStreamContext(); // Build our subscription options. Durable is REQUIRED for pull based subscriptions PullSubscribeOptions pullOptions = PullSubscribeOptions.Builder() .WithDurable(helper.Durable) // required .Build(); // 0.1 Initialize. subscription // 0.2 Flush outgoing communication with/to the server, useful when app is both JsUtils.Publishing and subscribing. // 0.3 Start the pull, you don't have to call this again because AckMode.NEXT // - When we ack a batch message the server starts preparing or adding to the next batch. Console.WriteLine("\n----------\n0. Initialize the subscription and pull."); IJetStreamPullSubscription sub = js.PullSubscribe(helper.Subject, pullOptions); c.Flush(1000); // 1. Publish some that is less than the batch size. Console.WriteLine("\n----------\n1. Publish some amount of messages, but not entire batch size."); JsUtils.Publish(js, helper.Subject, "A", 6); sub.PullExpiresIn(10, 1200); IList <Msg> messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 6 total messages, we received: " + messages.Count); // 2. Publish some more covering our pull size... Console.WriteLine("----------\n2. Publish more than the batch size."); sub.PullExpiresIn(10, 1200); JsUtils.Publish(js, helper.Subject, "B", 14); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 3. There are still 4 messages from B, but the batch was finished // - won't get any messages until a pull is issued. Console.WriteLine("----------\n3. Read without issuing a pull."); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 0 total messages, we received: " + messages.Count); // 4. re-issue the pull to get the last 4 Console.WriteLine("----------\n4. Issue the pull to get the last 4."); sub.PullExpiresIn(10, 1200); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 4 total messages, we received: " + messages.Count); // 5. publish a lot of messages Console.WriteLine("----------\n5. Publish a lot of messages. The last pull was under the batch size."); Console.WriteLine(" Issue another pull with batch size less than number of messages."); JsUtils.Publish(js, helper.Subject, "C", 25); sub.PullExpiresIn(10, 1200); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 6. there are still more messages Console.WriteLine("----------\n6. Still more messages. Issue another pull with batch size less than number of messages."); sub.PullExpiresIn(10, 1200); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 7. there are still more messages Console.WriteLine("----------\n7. Still more messages. Issue another pull with batch size more than number of messages."); sub.PullExpiresIn(10, 1200); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 5 total messages, we received: " + messages.Count); // 8. we got them all Console.WriteLine("----------\n8. No messages left."); sub.PullExpiresIn(10, 1200); messages = JsUtils.ReadMessagesAck(sub, timeout: 2000); Console.WriteLine("We should have received 0 total messages, we received: " + messages.Count); Console.WriteLine("----------\n"); // delete the stream since we are done with it. jsm.DeleteStream(helper.Stream); } } catch (Exception ex) { helper.ReportException(ex); } }
public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("Pull Subscription using primitive No Wait, Use Cases", args, Usage) .DefaultStream("nowait-uc-stream") .DefaultSubject("nowait-uc-subject") .DefaultDurable("nowait-uc-durable") .Build(); try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // Use the utility to create a stream stored in memory. JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, helper.Subject); // Create our JetStream context. IJetStream js = c.CreateJetStreamContext(); // Build our subscription options. Durable is REQUIRED for pull based subscriptions PullSubscribeOptions pullOptions = PullSubscribeOptions.Builder() .WithDurable(helper.Durable) // required .Build(); // 0.1 Initialize. subscription // 0.2 DO NOT start the pull, no wait works differently than regular pull. // With no wait, we have to start the pull the first time and every time the // batch size is exhausted or no waits out. // 0.3 Flush outgoing communication with/to the server, useful when app is both publishing and subscribing. Console.WriteLine("\n----------\n0. Initialize the subscription and pull."); IJetStreamPullSubscription sub = js.PullSubscribe(helper.Subject, pullOptions); c.Flush(1000); // 1. Start the pull, but there are no messages yet. // - Read the messages // - Since there are less than the batch size, we get them all (0) Console.WriteLine("----------\n1. There are no messages yet"); sub.PullNoWait(10); IList <Msg> messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 0 total messages, we received: " + messages.Count); // 2. Publish 10 messages // - Start the pull // - Read the messages // - Since there are exactly the batch size we get them all Console.WriteLine("----------\n2. Publish 10 which satisfies the batch"); JsUtils.Publish(js, helper.Subject, "A", 10); sub.PullNoWait(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 3. Publish 20 messages // - Start the pull // - Read the messages Console.WriteLine("----------\n3. Publish 20 which is larger than the batch size."); JsUtils.Publish(js, helper.Subject, "B", 20); sub.PullNoWait(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 4. There are still messages left from the last // - Start the pull // - Read the messages Console.WriteLine("----------\n4. Get the rest of the publish."); sub.PullNoWait(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 5. Publish 5 messages // - Start the pull // - Read the messages Console.WriteLine("----------\n5. Publish 5 which is less than batch size."); JsUtils.Publish(js, helper.Subject, "C", 5); sub.PullNoWait(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 5 total messages, we received: " + messages.Count); // 6. Publish 14 messages // - Start the pull // - Read the messages // - we do NOT get a nowait status message if there are more or equals messages than the batch Console.WriteLine("----------\n6. Publish 14 which is more than the batch size."); JsUtils.Publish(js, helper.Subject, "D", 14); sub.PullNoWait(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count); // 7. There are 4 messages left // - Start the pull // - Read the messages // - Since there are less than batch size the last message we get will be a status 404 message. Console.WriteLine("----------\n7. There are 4 messages left, which is less than the batch size."); sub.PullNoWait(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 4 messages, we received: " + messages.Count); Console.WriteLine("----------\n"); // delete the stream since we are done with it. jsm.DeleteStream(helper.Stream); } } catch (Exception ex) { helper.ReportException(ex); } }
public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("NATS JetStream Push Subscribe Bind Durable", args, Usage) .DefaultStream("fs-stream") .DefaultSubject("fs-subject") .Build(); string subjectNoAck = helper.Subject + "noack"; string subjectAck = helper.Subject + "ack"; string deliverNoAck = helper.DeliverSubject + "noack"; string deliverAck = helper.DeliverSubject + "ack"; try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // Use the utility to create a stream stored in memory. JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, subjectNoAck, subjectAck); // Create our JetStream context. IJetStream js = c.CreateJetStreamContext(); // The server uses the delivery subject as both an inbox for a JetStream subscription // and as a core nats messages subject. // BUT BE CAREFUL. THIS IS STILL A JETSTREAM SUBJECT AND ALL MESSAGES // ADHERE TO THE ACK POLICY // NoAck 1. Set up the noAck consumer / deliver subject configuration ConsumerConfiguration cc = ConsumerConfiguration.Builder() .WithAckPolicy(AckPolicy.None) .WithAckWait(1000) .Build(); PushSubscribeOptions pso = PushSubscribeOptions.Builder() .WithDeliverSubject(deliverNoAck) .WithConfiguration(cc) .Build(); // NoAck 2. Set up the JetStream and core subscriptions // Notice the JetStream subscribes to the real subject // and the core subscribes to the delivery subject // Order matters, you must do the JetStream subscribe first // But you also must make sure the core sub is made // before messages are published IJetStreamPushSyncSubscription jsSub = js.PushSubscribeSync(subjectNoAck, pso); c.Flush(5000); ISyncSubscription coreSub = c.SubscribeSync(deliverNoAck); // NoAck 3. JsUtils.Publish to the real subject JsUtils.Publish(js, subjectNoAck, "A", 1); // NoAck 4. Read the message with the js no ack subscription. No need to ack Msg msg = jsSub.NextMessage(1000); PrintMessage("\nNoAck 4. Read w/JetStream sub", msg); // NoAck 5. Read the message with the core subscription on the // no ack deliver subject. Since this message is a JetStream // message we could ack. But we don't have to since the consumer // was setup as AckPolicy None msg = coreSub.NextMessage(1000); PrintMessage("NoAck 5. Read w/core sub", msg); // NoAck 6. Thread.Sleep longer than the ack wait period to check and make sure the // message is not replayed Thread.Sleep(1100); try { coreSub.NextMessage(1000); Console.WriteLine("NoAck 6. NOPE! Should not have gotten here"); } catch (NATSTimeoutException) // timeout means there are no messages available { Console.WriteLine("NoAck 6. Read w/core sub.\nAck Policy is none so no replay even though message was not Ack'd.\nThere was no message available."); } // Ack 1. Set up the Ack consumer / deliver subject configuration cc = ConsumerConfiguration.Builder() .WithAckPolicy(AckPolicy.Explicit) .WithAckWait(1000) .Build(); pso = PushSubscribeOptions.Builder() .WithDeliverSubject(deliverAck) .WithConfiguration(cc) .Build(); // Ack 2. Set up the JetStream and core subscriptions jsSub = js.PushSubscribeSync(subjectAck, pso); c.Flush(5000); coreSub = c.SubscribeSync(deliverAck); // Ack 3. JsUtils.Publish to the real subject JsUtils.Publish(js, subjectAck, "B", 1); // Ack 4. Read the message with the js no ack subscription. No need to ack msg = jsSub.NextMessage(1000); PrintMessage("\nAck 4. Read w/JetStream sub", msg); // Ack 5. Read the message with the core subscription on the // ack deliver subject. // Even though it is read on a core subscription // it still is a JetStream message. Don't ack this time msg = coreSub.NextMessage(1000); PrintMessage("Ack 5. Read w/core sub", msg); // Ack 6. Thread.Sleep longer than the ack wait period to check and // see that the message is re-delivered. Ack this time. Thread.Sleep(1100); msg = coreSub.NextMessage(1000); msg.Ack(); PrintMessage("Ack 6. Read w/core sub.\nWasn't Ack'd after step 'Ack 5.' so message was replayed.", msg); // Ack 7. Thread.Sleep longer than the ack wait period. The message // is not re-delivered this time Thread.Sleep(1100); try { coreSub.NextMessage(1000); Console.WriteLine("Ack 7. NOPE! Should not have gotten here"); } catch (NATSTimeoutException) // timeout means there are no messages available { Console.WriteLine("Ack 7. Read w/core sub.\nMessage received by core sub in step 'Ack 6.' was JetStream so it was Ack'd and therefore not replayed.\nThere was no message available.", msg); } // delete the stream since we are done with it. jsm.DeleteStream(helper.Stream); } } catch (Exception ex) { helper.ReportException(ex); } }
public static void Main(string[] args) { ArgumentHelper helper = new ArgumentHelperBuilder("Pull Subscription using primitive Batch Size, Use Cases", args, Usage) .DefaultStream("pull-stream") .DefaultSubject("pull-subject") .DefaultDurable("pull-durable") .Build(); try { using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions())) { // Create a JetStreamManagement context. IJetStreamManagement jsm = c.CreateJetStreamManagementContext(); // Use the utility to create a stream stored in memory. JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, helper.Subject); // Create our JetStream context. IJetStream js = c.CreateJetStreamContext(); // Build our subscription options. Durable is REQUIRED for pull based subscriptions PullSubscribeOptions pullOptions = PullSubscribeOptions.Builder() .WithDurable(helper.Durable) // required .Build(); // 0.1 Initialize. subscription // 0.2 Flush outgoing communication with/to the server, useful when app is both JsUtils.Publishing and subscribing. // 0.3 Start the pull, you don't have to call this again because AckMode.NEXT // - When we ack a batch message the server starts preparing or adding to the next batch. Console.WriteLine("\n----------\n0. Initialize the subscription and pull."); IJetStreamPullSubscription sub = js.PullSubscribe(helper.Subject, pullOptions); c.Flush(1000); sub.Pull(10); // 1. JsUtils.Publish some that is less than the batch size. // - Do this first as data will typically be published first. Console.WriteLine("----------\n1. JsUtils.Publish some amount of messages, but not entire batch size."); JsUtils.Publish(js, helper.Subject, "A", 4); IList <Msg> messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 4 total messages, we received: " + messages.Count); // 2. JsUtils.Publish some more covering our pull size... // - Read what is available, expect only 6 b/c 4 + 6 = 10 Console.WriteLine("----------\n2. JsUtils.Publish more than the remaining batch size."); JsUtils.Publish(js, helper.Subject, "B", 10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 6 total messages, we received: " + messages.Count); // 3. There are still 4 messages from B, but the batch was finished // - won't get any messages until a pull is issued. Console.WriteLine("----------\n3. Read without re-issue."); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 0 total messages, we received: " + messages.Count); // 4. re-issue the pull to get the last 4 Console.WriteLine("----------\n4. Re-issue to get the last 4."); sub.Pull(10); messages = JsUtils.ReadMessagesAck(sub); Console.WriteLine("We should have received 4 total messages, we received: " + messages.Count); Console.WriteLine("----------\n"); // delete the stream since we are done with it. jsm.DeleteStream(helper.Stream); } } catch (Exception ex) { helper.ReportException(ex); } }