public void Listen(Action <string> message)
{
// configuration for kafka to find brokers
var config = new Dictionary <string, object>
{
{
"group.id", "booking_consumer"
},
{
"bootstrap.servers", "localhost:9092"
},
{
"enable.auto.commit", "false"
}
};
// subscribe consumer to producer topics
// null is there because we are not using consumer/producer keys
using (var consumer = new Confluent.Kafka.Consumer <Confluent.Kafka.Null, string>(config, null, new Confluent.Kafka.Serialization.StringDeserializer(Encoding.UTF8)))
{
// consumer subscribing to the topic
consumer.Subscribe("first_topic");
consumer.OnMessage += (_, msg) =>
{
message(msg.Value);
};
while (true)
{
consumer.Poll(100);
}
}
}
/// <summary>
/// In this example
/// - offsets are manually committed.
/// - consumer.Consume is used to consume messages.
/// (all other events are still handled by event handlers)
/// - no extra thread is created for the Poll (Consume) loop.
/// </summary>
public static void Run_Consume(Dictionary <string, object> constructConfig, List <string> topics, CancellationTokenSource cancellationTokenSource)
{
using (var consumer = new Confluent.Kafka.Consumer <Confluent.Kafka.Ignore, string>(constructConfig, null, new StringDeserializer(Encoding.UTF8)))
{
// Note: All event handlers are called on the main thread.
consumer.OnPartitionEOF += (_, end)
=> Console.WriteLine($"Reached end of topic {end.Topic} partition {end.Partition}, next message will be at offset {end.Offset}");
consumer.OnError += (_, error)
=> Console.WriteLine($"Error: {error}");
consumer.OnConsumeError += (_, error)
=> Console.WriteLine($"Consume error: {error}");
consumer.OnPartitionsAssigned += (_, partitions) =>
{
Console.WriteLine($"Assigned partitions: [{string.Join(", ", partitions)}], member id: {consumer.MemberId}");
consumer.Assign(partitions);
};
consumer.OnPartitionsRevoked += (_, partitions) =>
{
Console.WriteLine($"Revoked partitions: [{string.Join(", ", partitions)}]");
consumer.Unassign();
};
consumer.OnStatistics += (_, json)
=> Console.WriteLine($"Statistics: {json}");
consumer.Subscribe(topics);
Console.WriteLine($"Started consumer, Ctrl-C to stop consuming");
//var cancelled = false;
//Console.CancelKeyPress += (_, e) =>
//{
// e.Cancel = true; // prevent the process from terminating.
// cancelled = true;
//};
while (!cancellationTokenSource.IsCancellationRequested)
{
Confluent.Kafka.Message <Confluent.Kafka.Ignore, string> msg;
if (!consumer.Consume(out msg, TimeSpan.FromMilliseconds(100)))
{
continue;
}
Console.WriteLine($"Topic: {msg.Topic} Partition: {msg.Partition} Offset: {msg.Offset} {msg.Value}");
if (msg.Offset % 5 == 0)
{
Console.WriteLine($"Committing offset");
var committedOffsets = consumer.CommitAsync(msg).Result;
Console.WriteLine($"Committed offset: {committedOffsets}");
}
}
}
}
public static void Run_Poll(Dictionary <string, object> constructConfig, List <string> topics, CancellationTokenSource cancellationTokenSource)
{
StartProcess sp = new StartProcess();
try
{
using (var consumer = new Confluent.Kafka.Consumer <Confluent.Kafka.Null, string>(constructConfig, null, new StringDeserializer(Encoding.UTF8)))
{
sp.Log("Run_Poll Start");
// Note: All event handlers are called on the main thread.
consumer.OnMessage += (_, msg) =>
{ /*sp.Log(msg.Value)*/;
ProcessKafkaMessage.InsertInto_StgKafka(msg); };
consumer.OnPartitionEOF += (_, end) =>
{
sp.Log($"Reached end of topic {end.Topic} partition {end.Partition}, next message will be at offset {end.Offset}");
Console.WriteLine($"Reached end of topic {end.Topic} partition {end.Partition}, next message will be at offset {end.Offset}");
checkReachedEnd = true;
};
// Raised on critical errors, e.g. connection failures or all brokers down.
consumer.OnError += (_, error) =>
{
sp.Log($"Error: {error}");
Console.WriteLine($"Error: {error}");
};
// Raised on deserialization errors or when a consumed message has an error != NoError.
consumer.OnConsumeError += (_, msg) =>
{
sp.Log($"Error consuming from topic/partition/offset {msg.Topic}/{msg.Partition}/{msg.Offset}: {msg.Error}");
Console.WriteLine($"Error consuming from topic/partition/offset {msg.Topic}/{msg.Partition}/{msg.Offset}: {msg.Error}");
};
consumer.OnOffsetsCommitted += (_, commit) =>
{
Console.WriteLine($"[{string.Join(", ", commit.Offsets)}]");
sp.Log(string.Join(", ", commit.Offsets));
if (commit.Error)
{
Console.WriteLine($"Failed to commit offsets: {commit.Error}");
}
Console.WriteLine($"Successfully committed offsets: [{string.Join(", ", commit.Offsets)}]");
};
consumer.OnPartitionsAssigned += (_, partitions) =>
{
Console.WriteLine($"Assigned partitions: [{string.Join(", ", partitions)}], member id: {consumer.MemberId}");
//partitions.RemoveAt(2);
//partitions.RemoveAt(1);
consumer.Assign(partitions);
};
consumer.OnPartitionsRevoked += (_, partitions) =>
{
Console.WriteLine($"Revoked partitions: [{string.Join(", ", partitions)}]");
consumer.Unassign();
};
consumer.OnStatistics += (_, json) => Console.WriteLine($"Statistics: {json}");
consumer.Subscribe(topics);
Console.WriteLine($"Subscribed to: [{string.Join(", ", consumer.Subscription)}]");
//var cancelled = false;
//Console.CancelKeyPress += (_, e) =>
//{
// e.Cancel = true; // prevent the process from terminating.
// cancelled = true;
//};
sp.Log("Berfore Wile loop");
Console.WriteLine("Ctrl-C to exit.");
while (!cancellationTokenSource.IsCancellationRequested)
{
consumer.Poll(TimeSpan.FromMilliseconds(1000));
if (checkReachedEnd)
{
break;
}
}
//consumer.CommitAsync();
sp.Log("Run_Poll End");
}
}
catch (Exception ex)
{
sp.Log("Exeception in Run_Poll ");
sp.Log(ex.ToString());
throw;
}
}
static void Main(string[] args)
{
var builder = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appSettings.json");
Configuration = builder.Build();
var brokerList = Configuration.GetSection("brokers").GetChildren().Select(x => x.Value).ToArray();
var config = new Dictionary <string, object>
{
{ "bootstrap.servers", String.Join(" ", brokerList) },
{ "group.id", Configuration["groupId"] },
{ "enable.auto.commit", true },
{ "auto.commit.interval.ms", 5000 },
{ "statistics.interval.ms", 60000 },
{ "default.topic.config", new Dictionary <string, object>()
{
{ "auto.offset.reset", "smallest" }
} }
};
using (var consumer = new Confluent.Kafka.Consumer <Confluent.Kafka.Null, string>(config, null, new StringDeserializer(Encoding.UTF8)))
{
var topicName = Configuration["topicName"];
consumer.Assign(new List <Confluent.Kafka.TopicPartitionOffset> {
new Confluent.Kafka.TopicPartitionOffset(topicName, 0, 0)
});
consumer.OnMessage += (_, msg)
=> Console.WriteLine($"Topic: {msg.Topic} Partition: {msg.Partition} Offset: {msg.Offset} {msg.Value}");
consumer.OnPartitionEOF += (_, end)
=> Console.WriteLine($"Reached end of topic {end.Topic} partition {end.Partition}, next message will be at offset {end.Offset}");
consumer.OnError += (_, error)
=> Console.WriteLine($"Error: {error}");
consumer.OnConsumeError += (_, msg)
=> Console.WriteLine($"Error consuming from topic/partition/offset {msg.Topic}/{msg.Partition}/{msg.Offset}: {msg.Error}");
consumer.OnOffsetsCommitted += (_, commit) =>
{
Console.WriteLine($"[{string.Join(", ", commit.Offsets)}]");
if (commit.Error)
{
Console.WriteLine($"Failed to commit offsets: {commit.Error}");
}
Console.WriteLine($"Successfully committed offsets: [{string.Join(", ", commit.Offsets)}]");
};
consumer.OnPartitionsAssigned += (_, partitions) =>
{
Console.WriteLine($"Assigned partitions: [{string.Join(", ", partitions)}], member id: {consumer.MemberId}");
consumer.Assign(partitions);
};
consumer.OnPartitionsRevoked += (_, partitions) =>
{
Console.WriteLine($"Revoked partitions: [{string.Join(", ", partitions)}]");
consumer.Unassign();
};
consumer.OnStatistics += (_, json)
=> Console.WriteLine($"Statistics: {json}");
consumer.Subscribe(topicName);
Console.WriteLine($"Subscribed to: [{string.Join(", ", consumer.Subscription)}]");
var cancelled = false;
Console.CancelKeyPress += (_, e) => {
e.Cancel = true; // prevent the process from terminating.
cancelled = true;
};
Console.WriteLine("Ctrl-C to exit.");
while (!cancelled)
{
consumer.Poll(TimeSpan.FromMilliseconds(100));
}
}
}
