I am deploying two Java application with JMX server. The two sending message to JMX Client. However I can't differentiate where the message come from.
How to retrieve IP address of JMX Notification message?
There's no built in way to determine this, but here's a couple of suggestions :
On the notification sender side, add an app id to the notifications user-data or the source so the listener can distinguish between senders.
On the listener side, you could specify the same identifier as the handback object when you register the listener. That way you will know which source the notification came from.
Related
I'm using mosquitto as broker and paho(python) as client. I'm trying to make subscriber to receive offline messages.
For that I made following changes:
Fixed client ID
qos level 2
but, still the subscriber is not able to receive messages.
any help?
Thanks,
Rahul
In order to have your client as a durable client and receive messages that were sent to topics when it was offline, you need to meet the following criteria:
Fixed client ID (as you've done)
Always connect with clean_session=False
Subscriptions must be made with QoS>0
Messages published must have QoS>0
The mistake that I make most frequently is to forget either one of points 3 and 4, so I'm publishing with QoS=0 or subscribing with QoS=0, either of which would cause messages not to be stored.
You could also look at the queue_qos0_messages option to tell the broker to store QoS=0 messages as well. Note that this is an implementation detail that may be specific to mosquitto.
Check if you have set the retain flag to true when publishing message to topic, with retain=true, new connected client which subscribes the topic will receive the retained message.
I am working on an application which GET and POST information to a server. I am doing so using AFNetworking framework. My aim is to push a notification to a client whenever someone posts new info to the server. Eg: a new grade is published, the student who's grade was published must receive a notification on his iDevice.
Although I am not familiar with how Apple Push Notification works, from what I read I concluded that I need to add server side code in order to trigger a notification.
Note that I don't have access to the server. Service is provided by Fedena.
Any suggestions or hints from where to start?
APNS needs a server in order to work. The usual flow goes like this:
The iOS Application asks user to enable push notifications
Upon access granted, a device token is generated and then must be sent to the server.
Your server must be setup with the proper APNS certificates generated from the Apple Developer site
Then in your server's, when a new post is created, you need to add some logic where you load all the APNS token you've received already and then send the notification to the devices.
This is a very simple flow description but I guess you understood that you need to have access to the server to be able to do what you are trying to achieve.
Some third parties exists to handle push notifications (like Urban Airship), but those push notifications are usually pushed manually from a person, and not triggered from a server event
I recommend that you can use secondary server of your own as intermediate and use it as infrastructure back bone.You can use SignalR library. Use secondary server as to create connection between two devises. One client will push events and another client will listen to events.
Here is the link to the signalR library code written in IOS.
I am currently using these library. What you can do is start hub and connection using these library.
This library allows invoking method on server. Something like this.
[_hub invoke:#"MehtodName" withArgs:params];
What i would do is to create event registry on server. So one client can listen to event on server and other can push events or vice versa.
So your student device can invoke method "subscribe to events" and server will add it into the registry list. You can create secondary service "Publish Events". Grade publisher can publish via calling this method. Here publish events will look up registry and find interested clients and call desired method on client.
Read more about signalr through this site.
Benefit of using Signalr Over APNS.
Cost Effective. As this will save you money which you might have to pay to Apple for pushing notification.
Can Easily make it cross plateform in future. Just have to impletement similar library in Android/Windows.
Quicker as the data does not travel to apple server from your server.
Worst case you can fallback to apns any day, just put push notification code in any of your secondary server methods.
I have done battery and performance testing as well and works perfectly fine.
If you wanna know, here how it handles connection which is very reliable.
SRAutoTransport chooses the best supported transport for both client
and server. This achieved by falling back to less performant
transports. The default transport fallback is:
SRWebSocketTransport
SRServerSentEventsTransport
SRLongPollingTransport
Let me know if you have anyother question. i am currently doing similar work, might be able to help you with your issue.
i went through this question
Lost messages over XMPP on device disconnected
but there is no answer.
When a connection is lost due to some network issue then the server is not able to recognize it and keeps on sending messages to disconnected receiver which are permanently lost.
I have a workaround in which i ping the client from server and when the client gets disconnected server is able to recognize it after 10 sec and save further messages in queue preventing them from being lost.
my question is can 100% fail save message delivery be achieved by using some other way i know psi and many other xmpp client are doing it.
on ios side i am using xmppframework
One way is to employ the Advanced Message Processing (AMP) on your server; another one is to employ the Message Delivery Receipts on your clients.
The former one requires an AMP-enabled server implementation and the initiating client has to be able to tell the server what kind of delivery status reports it wants (it wants an error to be returned if the delivery is not possible). Note that this is not bullet-proof anyway as there is a window between the moment the target client losts its connectivity with the server and the moment the TCP stack on the server's machine detects this and tells the server about it: during this window, everything sent to the client is considered by the server to be sent okay because there's no concept of message boundaries in the TCP layer and hence if the server process managed to stuff a message stanza's XML into the system buffers of its TCP connection, it considers that stanza to be sent—there's no way for it to know which bits of its stream did not get to the receiver once the TCP stack says the connection is lost.
The latter one is bullet-proof as the clients rely on explicit notifications about message reception. This does increase chattiness though. In return, no server support for this feature is required—it's implemented solely in the clients.
go with XEP-0198 and enjoy...
http://xmpp.org/extensions/xep-0198.html
For a XMPP client I'm working on, the following mechanism is used:
Add Reachability to the project, to detect quickly when the phone is having connectivity problems.
Use a modified version of XEP-0198, adding a confirmation sent by the server. So, the client sends a message, the server confirms with a receipt. Later on, the receiving user will also confirm with a receipt. For each message you send, you get two confirmations, one from the server, one from the client. This requires modifications on the server of course.
When the app is not connected to the XMPP server, messages are queued.
When the app is logged in again to the XMPP server, the app takes all messages which were not confirmed by the server and sends them again.
For this to work, you have to locally store the messages in the app with three possible states: "Not sent", "Confirmed by server", "Confirmed by user"
I've been looking for an answer everywhere to no avail. I've developed an app for a client. This client works with money online so he has great security on his servers and the normal security policies, one of these policies is restricting external connections from domains, so the only way to register connections is by specific IP addresses. My problem is that the framework responsible of sending push notifications waits for an answer from the server to know if the push notification was delivered to a user, if the server response timeouts or the response says the notification was undelivered, the framework tries to send that notification again. This process is tried three times and after the third the framework doesn't even check for delivery status anymore and keeps working on the rest of notifications. The problem is that apple responses come from different IPs and if the IP responding is not one of the IPs registered on the client's security policy, the final user will receive three push notifications instead of just one.
I`ve been trying to get the IPs by trial and error but it is frustrating and I've got more than 30 different IPs so far. Is there any documentation of the IPs Apple uses to respond to push notifications? Has anyone got a list of IPs by any other means?
Sorry for the long post.
According to this technical note from Apple:
The IP address range for the push service is subject to change; the expectation is that providers will connect by hostname rather than IP address. The push service uses a load balancing scheme that yields a different IP address for the same hostname. However, the entire 17.0.0.0/8 address block is assigned to Apple, so you can specify that range in your firewall rules.
If I am writing a MIDlet, and if the device supports SMS push registration (i.e. supports WMA 1.1 spec), I will be able to send push messages to the application that is installed on the phone and is listening to SMS messages at the assigned port.
However, if I am writing a Blackberry application, can I still go ahead and use the procedure that applies to MIDP 2.0 devices. If so, can I specify static SMS push registration in JAD file, as we do for a MIDlet?
Would the appropriate JAD property be still specified as MIDlet-Push-1:{}?
Another question, that is not totally unrelated is- are there any bulk SMS providers that allow SMS bearers specify the destination ports that can be integrated with this kind of a solution?
Thanks
A regular blackberry application does not support the push registry. You'll have to keep a DatagramConnection open and listen for the incoming SMS messages that way.
DatagramConnection connection = (DatagramConnection)Connector.open("sms://:1234");
Datagram dgram = connection.newDatagram(connection.getMaximumLength());
connection.receive(dgram); // blocking call so this should be in a separate thread
String message = new String(dgram.getData());
where 1234 is the port you're listening on.
As to you're second question I'm not entirely sure, but I think mblox supports port directed SMS.
For the second question, if the bulk SMS service provider provides you with HTTP API which included the UDH field, you can send messages to application listening in that particular port