I develop the Android watch/phone application pair, where watch and phone communicate using Data API.
I need to pass the messages immediately, or with few minutes delay at most (not 30 minutes). To achieve so, I call setUrgent() on my PutDataRequest.
For the reasons I do not understand, the message still takes very long time to deliver.
The message is delivered immediately if I try to play with the stock Android Wear app changing the watch face. Also, after the first message is delivered, others seem passing immediately. However, after some longer time of inactivity (few hours) the slow delivery problem resumes.
I have updated Google Play Services to 10.2.1, I tried to use GoogleApiClient.reconnect() on every action, I have removed all threading from the connectivity listeners - no help. Even rebooting both watch and phone does not pull out the pair of the stalled communication state.
From watching the logs, seems that one side sends the message, other just does not receive it. The sending side receives own data message instead.
As the communication is bidirectional, and messages may come at any time, I need to keep the connection permanent. The sender tries to connect before sending the message, and the onConnected listener is called, yet the message is not delivered immediately.
Is anything is required to deliver messages immediately, in addition to calling of the setUrgent method? Which kind of magic the Android Wear app does that not only it has no problems of communicating, and even pushes my "forgotten" messages through?
If you needs some additional information for diagnostics, please tell me how to debug.
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I have an mobile application (iOS and Android) and I need send some notification from my server to these, then the mobile app need to make some tasks and when they finish, send a message from mobile to server to confirm. I have thought using Push Notification, but the problem is if the user disable this feature, the app will never receive this notification. Anyone know some direct communication server-app but keeping security?
You may try the long polling technique. But it will drain your battery very fast, so be careful. The main idea is that you set connectionTimeout to a very very long time (30 mins for example) and when not closing that connection until the server says there is something. After receiving an answer or timeout, just reopen it.
Another approach is to make some method like getJobStatus on the server, assign a unique id for your job and ask the server if it's complete every N minutes for example.
When trying to synchronise the client with the server, we usually need to combine both push and pull.
Something you can think of:
The server provides an API that allows the client to get the latest updates.
On the client side, when the app is active, use a timer to try fetching updates every N minutes.
When the app is in the background, use a background fetch to try fetching updates. In this case, the user doesn't care about if the task is done instantly, because his is not using it.
Call the getUpdates when the app becomes active from the background, to make sure handle the updates when the user starts to use it.
I am writing the app that can chat with other. I saw some project : Parse, GCM,... It is exactly good. But I need to know how it work. Because want to use my own.
In my case, I saw when other send his chat, then it's almost display on my screen after 1-2 seconds. Then I think what happened:
My friend post his chat to server, and server send request to app with ID ( unique).
In my app, there have a service, which send request to this server each 1 second to get new chat, or notification. If found, display in my device.
Is my above ideal true? I am going to write about chat with client-server.
Give me reason why down vote.
Thanks :)
In my app, there have a service, which send request to this server each 1 second to get new chat, or notification. If found, display in my device.
Implement as you say lead to energy(own app services use)/IO(every net request each 1 second)/server(large amount request from clients, and most of request is useless because nobody chat in 24h) waste, and message may lost or can't get notification in time if the service is killed by system(or don't start).
However, your method will work if you find a way to keep your service always alive, and make well design for servers to support large amount requests from large multi clients.
For the better, you can use dynamic look-up algorithm that keep a long interval if there is no notification recently.
I've written a small test application which works as a simple chat room using Nearby.MESSAGES_API.
When I subscribe I find that I receive a number of older Messages in my MessageListener (in onFound). If I disconnect and then reconnect (eg. switch to another application) I find that all the messages come through again. Is this meant to happen?
I have changed the application to include UUIDs in my messages and keep a stash of them to check whether I have received the message, but that may not be a good idea from a memory point of view (although I could put them in a database).
I don't understand how the "session" side of Nearby Messages works.
In Google Play Services 7.8 the "sessions" are internally divided into ten minute buckets. You're not the first person to be confused by this, we're looking at options to do this differently in the future. No promises, but we recognize it's an issue.
(I work on the Nearby API)
The issue was that publishAndSubscribe is called when onConnected is called. The issue with this is that onStart attempts to reconnect so publishAndSubscribe needn't be called again.
I'm creating mobile application for iOS and Android. The problem is when any data has changed on server, I cannot notify mobile devices.
I have found 3 solutions, each have minus and pluses.
Use push notifications. Since iOS always shows a notification to user this is not a solution at all. Also I cannot know if the notification will go to device or when it will.
For every X seconds ask server if any change exists. I don't want to do that, because creating too many HTTP connections and closing them is not a good idea I think. Also if the data is changed right after the device asks, the info change on device will occur late.
Use web socket. My application's one time usage expectation is ~2 minutes. So web socket looks like a good choice, because app will be terminated or go to background state quickly and battery consume won't be much. Also all the server side data changes will come to the device just in time. But I don't know much about web socket. Is my opinion acceptable? Also how many concurrent connections can be done by my server. Is it a question too.
Here are my all solutions.
The document would suggest assumption 1. above is incorrect.
If you read the The Notification Payload section, you'll come across this;
The aps dictionary can also contain the content-available property. The content-available property with a value of 1 lets the remote notification act as a “silent” notification. When a silent notification arrives, iOS wakes up your app in the background so that you can get new data from your server or do background information processing. Users aren’t told about the new or changed information that results from a silent notification, but they can find out about it the next time they open your app.
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html
I think for the most part this depends on what your app is doing.
I would say you should use a combination of #1 and #2.
2 - At the very base level if you need information from the server you are going to have to make a request. If this information needs to be up to date then you can proceed to make a request for the information when the ViewController is loaded. If you need this information to update as the ViewController is loaded then you will need to make subsequent requests every X seconds... In addition to this if your user is interacting with this data and sending an update to the server you can check at this point if the data is up to date and alert the user as well as return the current data.
1 - Push Notifications operate off of the 'send and forget' protocol. The notification is sent and is not verified if it is received or not. This is used as a supplement to #2 and is 'nice' but should not be depended upon.
Push notification is the intended way (from both Google through Google Cloud Messaging, and Apple through Apple Push Notification Service).
Both option 2 and 3 are frowned upon as they affect battery life, and they are unnecessary as most cases scenarios can be covered by push notifications.
we've been trying to develop an android application which uses the c2dm service of Google.
When we start the application after clearing all data, the application receives the c2dm messages just fine, but after some time (maybe 2 minutes) the messages refuse to arrive.
We also checked the code we received after pushing the c2dm messages from the server, and the code was successful (code number 200 without error).
After searching relevant posts on Stack Overflow, we came across this post:
Why do Android C2DM push messages not always arrive?
but we verified that we don't register to the c2dm service each time the application starts.
What seems to be the problem in our case?
We use android 2.2 API 8 version .
Thanks in advance,
Mark.
You should always have in mind that Google's C2DM allows a certain limit of messages/day. I'm thinking that sending a large number of messages in 2-3 minutes (a client-chat, or something like that) could be the source of your problem.
And also, have in mind that there is no guarantee whatsoever that messages will arrive. Per Google's C2DM Introduction: C2DM makes no guarantees about delivery or the order of messages. But you probably already know this.
I am thinking that if your 2-3 minute average is a rule, then probably the limitation of the messages could be the cause. Try sending fewer messages and see if the interval doesn't get larger.
"maybe 2 minutes" - you should confirm that first of all. You must clarify:
Is this issue related to this one device?
Does it happen consistently? If not, what triggers it?
Has it happened once, or does it happen every time?
Do bear in mind that C2DM messages are not guaranteed. Some will not arrive.
Also be aware that sometimes Android devices "fall off" c2dm and don't receive messages for a period of time. You will see similar effects on some networks (e.g. in my experience some C2DM messages are not delivered over wifi networks, so try 3G too).