Check RabbitMQ queue size from client

问题:

Does anyone know if there's a way to check the number of messages in a RabbitMQ queue from a client application?

I'm using the .NET client library.

回答1:

You actually can retrieve this via the client. When perform a queue_declare operation RabbitMQ returns a three tuple containing (<queue name>, <message count>, <consumer count>). The passive argument to queue_declare allows you to check whether a queue exists without modifying the server state. So you can use queue_declare with the passive option to check queue length. Not sure about .NET, but in Python it looks something like this:

name, jobs, consumers = chan.queue_declare(queue=queuename, passive=True)

回答2:

I am 2 years too late but I was searching for it myself and found that rabbitmq gives u simple script to communicate to erlang nodes..its in sbin folder where the starting script for RabbitMQ is located..so you can basically say

./rabbitmqctl list_queues

this will display the queues along with the count of messages pending to those queues similarly you can also say

./rabbitmqctl list_channels
./rabbitmqctl list_connections

etc. For more info you can visit here

回答3:

If you wanted to do this in .Net, check which version of the Client library you are using.

I'm using the 2.2.0 version and I had to use BasicGet(queue, noAck).
In this version of the Library QueueDeclare() only returns a string containing the queue name.

BasicGetResult result = channel.BasicGet("QueueName", false);
uint count = result != null ? result.MessageCount : 0;

I know from the 2.6.1 version, QueueDeclare() returns an object of type QueueDeclareOk.

QueueDeclareOk result = channel.QueueDeclare();
uint count = result.MessageCount;

Alternatively, you can call from the command line:

<InstallPathToRabbitMq>\sbin\rabbitmqctl.bat list_queues

And you see the following output:

Listing queues...
QueueName 1
...done.

HTH

回答4:

I'm using version 3.3.1 of the .Net Client Library.

I use the following, which is very similar to Ralph Willgoss second suggestion but you can supply the queue name as an argument.

QueueDeclareOk result = channel.QueueDeclarePassive(queueName);
uint count = result != null ? result.MessageCount : 0;

回答5:

Update: it appears that the pika implementation of queue_declare(..) has changed since mmalone's very helpful post.

In python/pika (v0.9.5) it's still possible to check the queue depth via pika, but it requires a slightly more indirect approach.

queue_declare(...) passes a method object into its callback function, which you can then inspect. For example, to check the number of messages and consumers in the queue named 'myQueue':

def cbInspect(qb):
    messagesInQueue = qb.method.message_count
    print "There are %d messages in myQueue" % messagesInQueue

    consumersInQueue = qb.method.consumer_count
    print "There are %d consumers in myQueue" % consumersInQueue

    return

myChannel = channel.queue_declare(callback=cbInspect, queue='myQueue', passive=True)

Hope this helps, and please go easy on me, I'm new around here :-)

回答6:

my little snippet based on Myydrralls' answer. I think if he had code in his answer I might have noticed it much quicker.

public uint GetMessageCount(string queueName)
{
    using (IConnection connection = factory.CreateConnection())
    using (IModel channel = connection.CreateModel())
    {
        return channel.MessageCount(queueName);
    }
}

回答7:

You can use the IModel's MessageCount method, documented here

http://www.rabbitmq.com/releases/rabbitmq-dotnet-client/v3.6.4/rabbitmq-dotnet-client-3.6.4-client-htmldoc/html/type-RabbitMQ.Client.IModel.html#method-M:RabbitMQ.Client.IModel.MessageCount(System.String)

edit: I know this is a very old post, but it is the first google response, and I hope it will help people looking for this answer in the future.

回答8:

At least as of RabbitMQ 3.3.5, you can do this in a C# program without any RabbitMQ client library by calling the RabbitMQ Management HTTP API:

// The last segment of the URL is the RabbitMQ "virtual host name". 
// The default virtual host name is "/", represented urlEncoded by "%2F".
string queuesUrl = "http://MY_RABBITMQ_SERVER:15672/api/queues/%2F";

WebClient webClient = new WebClient { Credentials = new NetworkCredential("MY_RABBITMQ_USERNAME", "MY_RABBITMQ_PASSWORD") };
string response = webClient.DownloadString(queuesUrl);

The username and password are the same as those you use to log into the RabbitMQ management console UI.

Response will be a JSON string with the list of queues, including their message counts, among other properties. (If you like, you can deserialize that JSON into a C# object using a library like Json.NET.)

The API documentation is installed along with the RabbitMQ management console and should be available on that server at http://MY_RABBITMQ_SERVER:15672/api .