A server is sending a message via Redis on a channel composed of some name and a unique id. I need to essentially find this channel and publish something back to it.
So far, I tried reading the documentation and experimenting with PSUBSCRIBE. However, the message that is received doesn't have the full channel name. It just has the pattern that I sent to PSUBSCRIBE. So, how can I go about finding the channel name?
I also included some code below if that would help understand my logic.
red = redis.StrictRedis(...)
pub = red.pubsub()
pub.psubscribe("name_pattern*")
for msg in pub.listen():
if msg["data"] == "...":
channel_name = msg["channel"]
red.publish(channel_name, "SOME MESSAGE")
Related
I am writing a .NET Console application, our goal is keep a message on the queue and read the message. the message header should contain User Name & Password. I try to pass the Message with below code it is not working.
hashTable.Add(MQC.TRANSPORT_PROPERTY, MQC.TRANSPORT_MQSERIES_CLIENT);
hashTable.Add(MQC.HOST_NAME_PROPERTY, strServerName);
hashTable.Add(MQC.CHANNEL_PROPERTY, strChannelName);
hashTable.Add(MQC.PORT_PROPERTY, 1414);
hashTable.Add(MQC.USER_ID_PROPERTY, "XXXXXX");
hashTable.Add(MQC.PASSWORD_PROPERTY, "XXXXXX");
hashTable.Add(MQC.USE_MQCSP_AUTHENTICATION_PROPERTY, true);
queueManager = new MQQueueManager(strQueueManagerName,hashTable);
queue = queueManager.AccessQueue(requestQueue, MQC.MQOO_OUTPUT + MQC.MQOO_FAIL_IF_QUIESCING);
requestMessage = new MQMessage();
requestMessage.WriteString(StrAPICMessage);
requestMessage.Format = MQC.MQFMT_STRING;
requestMessage.MessageType = MQC.MQMT_REQUEST;
requestMessage.Report = MQC.MQRO_COPY_MSG_ID_TO_CORREL_ID;
requestMessage.ReplyToQueueName = responseQueue;
requestMessage.ReplyToQueueManagerName = strQueueManagerName;
queuePutMessageOptions = new MQPutMessageOptions();
queue.Put(requestMessage, queuePutMessageOptions);
In the Message Descriptor it is taking the default value mentioned MQ Server. it is not takeing my UserName "XXXXX"
I have tried using the CSICS Bridge header also unable to send the message with my application Service account + Password.
help me on this scenario.
See "MQCSP authentication mode" here: https://www.ibm.com/docs/en/ibm-mq/latest?topic=authentication-connection-java-client
It says:
In this mode, the client-side user ID is sent as well as the user ID and password to be authenticated, so you are able to use ADOPTCTX(NO). The user ID and password are available to a server-connection security exit in the MQCSP structure that is provided in the MQCXP structure.
"client-side user ID" means the UserId that the application is running under. Therefore, if you are authenticating with a different UserId than the one that the application is running under.
Therefore, you (or your MQAdmin) will need to change ADOPTCTX to YES.
Your program works fine for me, when I fill in the correct values for my qmgr connection.
Except for one change I made: instead of TRANSPORT_MQSERIES_CLIENT I used TRANSPORT_MQSERIES_MANAGED. That keeps everything in the managed .Net space.
Without that change, I was actually getting MQRC_UNSUPPORTED_FUNCTION during the connection which typically means either some kind of mismatch between versions of interfaces, or it couldn't find the C dll that underpins the unmanaged environment. And I wasn't going to take time to dig into that further.
Running amqsbcg against the output queue, I see
UserIdentifier : 'mqguest '
which is the id I had set in the USER_ID_PROPERTY.
There are 2 methods in Telegram API that forward message:
messages.forwardMessage
messages.forwardMessages
I want to use forwardMessage method to forward a message from a channel, group or user to another one. Definition of this method is:
messages.forwardMessage#33963bf9 peer:InputPeer id:int random_id:long = Updates;
As you see this method has 3 input parameters:
peer that represents the channel, group or user that we forward message to. (Destination)
id that is message_id.
random_id that has internal use.
As we know the message_id is a unique number in a chat. so a message_id in a group has refers to a message that differs with the same message_id in other group.
So the main question is that how we determine the source peer of forwarding? Because the source peer is not determined by message_id.
P.S: My question is about methods in Telegram API, not Telegram Bot API.
There seems to an issue with ForwardMessageRequest which doesn't specify the source chat. Obviously message_id is not unique and through my tests I noticed wrong messages will be forwarded by just specifying the message_id. And I noticed message_id is not unique.
But the issue doesn't exist with ForwardMessagesRequest. Following is an example how to use the ForwardMessagesRequest version.
Forwarding Example:
Here is the code I used for testing (I am using Telethon for python, but it won't matter since it's directly calling telegram API):
source_chat = InputPeerChannel(source_chat_id, source_access_hash)
total_count, messages, senders = client.get_message_history(
source_chat, limit=10)
for msg in reversed(messages):
print ("msg:", msg.id, msg)
msg = messages[0]
print ("msg id:", msg.id)
dest_chat = InputPeerChat(dest_chat_id)
result = client.invoke(ForwardMessagesRequest(from_peer=source_chat, id=[msg.id], random_id=[generate_random_long()], to_peer=dest_chat))
I'm trying to write something for my iOS app, using RMQClient that scans for existing exchanges on a rabbitmq server. I came up with this so far.
class AMQPExchangeScanner {
static func scan() {
let connection:RMQConnection = RMQConnection(uri: "amqp://user:user#abc.def.com:5672", delegate: RMQConnectionDelegateLogger())
connection.start()
for exchangeName in Foo.pastExchanges() {
let channel = connection.createChannel()
let exchange = channel.fanout(exchangeName, options: .passive)
"scan \(exchangeName) \(exchange)".print()
channel.close()
}
}
}
I'm not sure how to determine if the exchange actually exists though. The print() statement prints exchange objects. I get a whole bunch of output in the console. I had hoped that I would get back an optional so I could do something like
if let exchange... {
}
But that doesn't appear to be the case. How do I programmatically check if the exchange is real or not? Or get at those errors? Do I need my own connection delegate and have to parse a bunch of text?
The best way to scan for existing exchanges is using rabbitmq management HTTP API - it would be under /api/exchanges.
For a single exchange you could call the declare method, with passive parameter set accordingly (quoting from here):
for the declare method
This method creates an exchange if it does not already exist, and if
the exchange exists, verifies that it is of the correct and expected
class.
for the passive bit
If set, the server will reply with Declare-Ok if the exchange already
exists with the same name, and raise an error if not.
...
If not set and the exchange exists, the server MUST check that the existing exchange has the same values for type, durable, and arguments fields. The server MUST respond with Declare-Ok if the requested exchange matches these fields, and MUST raise a channel exception if not.
I was currently using NMS to develop application based ActiveMQ(5.6).
We have several consumers(exe) trying to recieving massgaes from the same queue(not topic). While all the messages just all go to one consumer though I have make the consumer to sleep for seconds after recieving a message. By the way, we don't want the consumers recieving the same messages other consumers have recieved.
It is mentioned in the official website that we should set Prefetch Limit to decide how many messages can be streamed to a consumer at any point in time. And it can both be configured and coded.
One way I tried is to code using PrefetchPolicy class binding the ConnectionFactory class like bellow.
PrefetchPolicy poli = new PrefetchPolicy();
poli.QueuePrefetch = 0;
ConnectionFactory fac = new ConnectionFactory("activemq:tcp://Localhost:61616?jms.prefetchPolicy.queuePrefetch=1");
fac.PrefetchPolicy = poli;
using (IConnection con = fac.CreateConnection())
{
using (ISession se = con.CreateSession())
{
IDestination destination = SessionUtil.GetDestination(se, queue, DestinationType.Queue);
using (IMessageConsumer consumer = se.CreateConsumer(queue1))
{
con.Start();
while (true)
{
ITextMessage message = consumer.Receive() as ITextMessage;
Thread.Sleep(2000);
if (message != null)
{
Task.Factory.StartNew(() => extractAndSend(message.Text)); //do something
}
else
{
Console.WriteLine("No message received~");
}
}
}
}
}
But no matter what prefetch value I set the behavior of the consumers stay the same as before.
And I've tried the second way tying to get the result, namely configure the server conf file. I change the activemq.xml of the server like bellow.
" producerFlowControl="true" memoryLimit="5mb" />
" producerFlowControl="true" memoryLimit="5mb">
But though I've set the dispatchpolicy the messages still go to one consumer.
I want to know that:
Whether this behavior can be achieved by just configuring the server xml file to enable all the consumers recieve messages from one queue? If so, how to configure this and what is wrong with my configuration? If not, how can I use codes to achieve the goal?
Thanks.
Take a look at "Message Groups" feature.
I had the same problem. Only one consumer processed all messages. I found in my code I used group header during send:
request.Properties["NMSXGroupID"] = "cheese";
According to official docs:
Standard JMS header JMSXGroupID is used to define which message group
the message belongs to. The Message Group feature then ensures that
all messages for the same message group will be sent to the same JMS
consumer - while that consumer stays alive. As soon as the consumer
dies another will be chosen.
See full details at http://activemq.apache.org/message-groups.html
I need to remove/delete my topic subscriber. I found this http://activemq.apache.org/manage-durable-subscribers.html
However, it's not good enough for us. We want to control the timing of removing a subscriber, and no matter there are any message or not. Besides, our program is written by C#. So the best solution for us is NMS API.
Thanks.
Here are the code,
Apache.NMS.ActiveMQ.ConnectionFactory factory = new Apache.NMS.ActiveMQ.ConnectionFactory(m_brokerURI);
m_connection = factory.CreateConnection(username, password);
Apache.NMS.ActiveMQ.Connection con = (Apache.NMS.ActiveMQ.Connection)m_connection;
ISession session = m_connection.CreateSession(AcknowledgementMode.AutoAcknowledge);
try
{
session.DeleteDurableConsumer(strQueueName);
}
catch (Exception ex)
{
// log the error message
}
Update
Our scenario is quite simple.
A client built a queue and subscribed a consumer on a topic.
the client side closed the connection.
delete the consumer on the server side(as the example code in the last update)
Here is the snapshot of activemq broker via jconsole:
jconsole snapshot
We would like to remove the subscriber “7B0FD84D-6A2A-4921-967F-92B215E22751” by following method,
But always got this error "javax.jms.InvalidDestinationException : No durable subscription exists for: 7B0FD84D-6A2A-4921-967F-92B215E22751"
strSubscriberName = “7B0FD84D-6A2A-4921-967F-92B215E22751”
session.DeleteDurableConsumer(strSubscriberName);
To delete a durable subscription from the NMS API you use the DeleteDurableConsumer method defined in ISession. You must call this method from a Connection that uses the same client Id as was used when the subscription was created and you pass the name of the subscription that is to be removed. The method will fail if there is an active subscriber though so be prepared for that exception.
In the sample code you don't set a Client Id on the connection. When working with durable subscriptions you must, must, MUST always use the same client Id and subscription name. So in you same you will get this error until you set the client Id to the same value as the connection that created the subscription in the first place.