Perform multiple updates at once via Twitter4J on sincle account - exception

The Java class here works fine for me. My problem is that I can't perform more than 1 updates at once. In fact, Java throws a try-catch exception every time it reaches the following lines for second time:
try {
// get request token.
// this will throw IllegalStateException if access token is already available
RequestToken requestToken = twitter.getOAuthRequestToken();
...
As you can imagine, the class is being called multiple times within a for loop. So, any ideas?
PS: Hope not having messed up my question. :D

This should be done like this (pseudo code)
GetAccessToken
AuthenticateUser
Loop
doUpdate
CleanUp
Twitter4J "holds" a session for the authenticated user, so starting with a new, different user needs a new instance of the Twitter4J.

Related

My messages are delivered out of flow sequence order and how do I compensate?

I wish to use Twilio in the context of an adventure game. As the gamer (Geocacher) progresses on an actual treasure (cache) hunt, clues are given by text when certain code words or numbers are entered as part of the thread. I am very comfortable creating the flow in Studio and have a working flow that is debugged and ready to go.
Not so fast, grasshopper! Strange things started to happen when beta testing the flow. Basically texts that show as being sent arrive to the user out of sequence in the thread. The SM logs show everything is working correctly (message sent) but, what I call Zombie messages arrive to the user after a previous message has arrived. The Zombies are legitimate messages from the Flow but out of the correct sequence and that makes the thread unusable for my purposes.
I learned too late in my "programming" that Twilio states, "If you send multiple SMS messages to the same user in a short time, Twilio cannot guarantee that those messages will arrive in the order that you sent them." Ugh!
So , I started with the Help Techs at Twillio and one solution is to create a subflow that basically is inserted after a Send Message Widget. This sub flow basically Fetches the message via the SMS SID to check for SMS status. If status is "delivered", we can safely say the message has been received by the recipient and then permit the next message in the flow.
That sound great but I am not a programmer and will never be able to integrate the suggested code much less debug it when things don't work. There might be many other approaches that you guys can suggest. The task is 1.) Send a message, 2.) Run a subflow that checks for message delivery, 3.) send the next message in the sequence.
I need to move on to implementation and this type of sub flow is out of my wheelhouse. I am willing to pay for programming help.
I can post the JSON code that was created as a straw man but have no idea how to use it and if it is the optimum solution if that is of help. It would seem that a lot of folks experience this issue and would like a solution. A nice tight JSON subflow with directions on how to insert would seem to be a necessary part of the Widget toolkit provided by Twillio in Studio.
Please Help Me! =)
As you stated, the delivery of the message cannot be guaranteed. Checking the status of the sent message is the most reliable, using a subflow, a Twilio Function, or a combination. Just keep in mind that Twilio Functions have a 10s execution time limit. I don't expect delivering the SMS will take longer than 10s is most cases. If you're worried about edge cases, you'd have to loop the check for the status multiple times. I'll share a proof of concept later for this.
An easier way, but it still doesn't guarantee delivery order, would be to add some delay between each message. There's no built-in delay widget, but here's code on how to create a Twilio Function to add delays, up to 10s.
A more hacky way to implement delays without having to use this Twilio Function, is to use the Send & Wait For Reply Widget and configure the "Stop Gathering After" property to the amount of delay you'd like to add. If the user responds, connect to the next widget, if they don't also connect to the widget.
As mentioned earlier, here's th Subflow + Function proof of concept I hacked together:
First, create a Twilio Functions Service, in the service create two functions:
/delay:
// Helper function for quickly adding await-able "pauses" to JavaScript
const sleep = (delay) => new Promise((resolve) => setTimeout(resolve, delay));
exports.handler = async (context, event, callback) => {
// A custom delay value could be passed to the Function, either via
// request parameters or by the Run Function Widget
// Default to a 5 second delay
const delay = event.delay || 5000;
// Pause Function for the specified number of ms
await sleep(delay);
// Once the delay has passed, return a success message, TwiML, or
// any other content to whatever invoked this Function.
return callback(null, `Timer up: ${delay}ms`);
};
/get-message:
exports.handler = function(context, event, callback) {
const messageSid = event.message_sid,
client = context.getTwilioClient();
if(!event.message_sid) throw "message_sid parameter is required.";
client.messages(messageSid)
.fetch()
.then(message => callback(null, message))
.catch((error) => {
console.error(error);
return callback(error);
});
};
Then, create a Studio Flow named something like "Send and Wait until Delivered".
In this flow, you send the message, grabbing the message body passed in from the parent flow, {{trigger.parent.parameters.message_body}}.
Then, you run the /get-message Function, and check the message status.
If delivered, set status variable to delivered. This variable will be passed back to the parent flow. If any of these accepted,queued,sending,sent, then the message is still in route, so wait a second using the /delay function, then loop back to the /get-message function.
If any other status, it is assumed there's something wrong and status is set to error.
Now you can create your parent flow where you call the subflow, specifying the message_body parameter. Then you can check the status variable for the subflow, whether it is 'delivered' or 'error'.
You can find the export for the subflow and the parent flow in this GitHub Gist. You can import it and it could be useful as a reference.
Personally, I'd add the /delay function, and use that after every message, adding a couple of seconds delay. I'd personally assume the delay adds enough buffer for no zombie messages to appear.
Note: The code, proof of concept, and advice is offered as is without liability to me or Twilio. It is not tested against a production workload, so make sure you test this thoroughly for your use case!

How to handle "Unexpected EOF at target" error from API calls?

I'm creating a Forge application which needs to get version information from a BIM 360 hub. Sometimes it works, but sometimes (usually after the code has already been run once this session) I get the following error:
Exception thrown: 'Autodesk.Forge.Client.ApiException' in mscorlib.dll
Additional information: Error calling GetItem: {
"fault":{
"faultstring":"Unexpected EOF at target",
"detail": {
"errorcode":"messaging.adaptors.http.flow.UnexpectedEOFAtTarget"
}
}
}
The above error will be thrown from a call to an api, such as one of these:
dynamic item = await itemApi.GetItemAsync(projectId, itemId);
dynamic folder = await folderApi.GetFolderAsync(projectId, folderId);
var folders = await projectApi.GetProjectTopFoldersAsync(hubId, projectId);
Where the apis are initialized as follows:
ItemsApi itemApi = new ItemsApi();
itemApi.Configuration.AccessToken = Credentials.TokenInternal;
The Ids (such as 'projectId', 'itemId', etc.) don't seem to be any different when this error is thrown and when it isn't, so I'm not sure what is causing the error.
I based my application on the .Net version of this tutorial: http://learnforge.autodesk.io/#/datamanagement/hubs/net
But I adapted it so I can retrieve multiple nodes asynchronously (for example, all of the nodes a user has access to) without changing the jstree. I did this to allow extracting information in the background without disrupting the user's workflow. The main change I made was to add another Route on the server side that calls "GetTreeNodeAsync" (from the tutorial) asynchronously on the root of the tree and then calls it on each of the returned children, then each of their children, and so on. The function waits until all of the nodes are processed using Task.WhenAll, then returns data from each of the nodes to the client;
This means that there could be many api calls running asynchronously, and there might be duplicate api calls if a node was already opened in the jstree and then it's information is requested for the background extraction, or if the background extraction happens more than once. This seems to be when the error is most likely to happen.
I was wondering if anyone else has encountered this error, and if you know what I can do to avoid it, or how to recover when it is caught. Currently, after this error occurs, it seems that every other api call will throw this error as well, and the only way I've found to fix it is to rerun the code (I use Visual Studio so I just rerun the server and client, and my browser launches automatically)
Those are sporadic errors from our apigee router due to latency issues in the authorization process that we are currently looking into internally.
When they occur please cease all your upcoming requests, wait for a few minutes and retry again. Take a look at stuff like this or this to help you out.
And our existing reports calling out similar errors seem to point to concurrency as one of the factors leading up to the issue so you might also want to limit your concurrent requests and see if that mitigate the issue.

How to bulk insert rows into realm database from web (JSON) in Xamarin

This is my very first attempt to work with Xamarin studio with Realm (to make app for both iOS and Android) and I am stuck at this situation since last 24 hours.
My online database-table has 30,000 rows. Earlier when I used to work in Android studio, I used to import those rows in app's 1st run with the help of JSON, GSON and insert into SQLite db.
But I am unable to do so in Realm & Xamarin. I know, I have not provided any code snippet (my effort), but honestly even after searching a lot about this, I couldn't find how should I proceed?
I've already answered that in the Github issue, but in case someone else stumbles across it, the best way to do that without blocking the UI thread, is to use the Realm.WriteAsync API. Basically, you'll do something like:
var items = await service.GetAllItems();
// I assume items are already deserialized RealmObject-s
var realm = Realm.GetInstance();
await realm.WriteAsync(r =>
{
foreach (var item in items)
{
r.Manage(item);
}
}
/* Data is loaded, show message or process it in other ways */
One thing to note is that within the WriteAsync lambda, we're using the r instance and not the original realm one. The reason is that because realms are not thread safe and the asynchronous write will happen on another thread, so it implicitly creates another instance and passes it as an argument of the action parameter.

sfErrorNotifierPlugin: The "default" context does not exist

I have installed the sfErrorNotifierPlugin. When both options reportErrors/reportPHPErrors reportPHPWarnings/reportWarnings are set to false, everything is ok. But I want to catch PHP exceptions and warnings to receive E-mails, but then all my tasks fail, including clear-cache. After few hours of tests I'm 100% sure that the problem is with set_exception_handler/set_error_handler.
There's a similar question:
sfErrorNotifierPlugin on symfony task but the author there is having problems with a custom task. In my case, even built-in tasks fail.
I haven't used sfErrorNotifierPlugin, but I have run into 'The “default” context does not exist.' messages before. It happens when a call is made to sfContext::getInstance() and the context simply doesn't exist. I've had this happen a lot from within custom tasks. One solution is to add sfContext::createInstance() before the call to sfContext::getInstance(). This will ensure that a context exists.
There's an interesting blog post on 'Why sfContext::getInstance() is bad' that goes into more detail - http://webmozarts.com/2009/07/01/why-sfcontextgetinstance-is-bad/
Well, the problem could not be solved this way, unfortunately. Using sfErrorNotifierPlugin, I have enabled reporting PHP warning/errors (apart from symfony exceptions) and this resulted in huge problems, e.g. built-in tasks such as clear-cache failed.
The solution I chose was to load the plugin only in non-task mode (project configuration class):
public function setup()
{
$this->enableAllPluginsExcept('sfPropelPlugin');
if ('cli' == php_sapi_name()) $this->disablePlugins('sfErrorNotifierPlugin');
}
WHen a task is executed, everything works normally. When an app is fired from the browser, emails are sent when exception/warning occurs (maybe someone will find it useful).
Arms has explained the problem correctly. But usually context does not exist when executing backend/maintenance tasks on the console. And it is easier if you handle the condition yourself.
Check, if you really need the context?
If you do, what exactly do you need it for?
Sometimes you only want a user to populate a created_by field. You can work around by hard-coding a user ID.
If you want to do something more integrated, create a page (which will have a context) and trigger the task from there.
you can test the existance of the instance before doing something inside a class. Like:
if(sfContext::hasInstance())
$this->microsite_id = sfContext::getInstance()->getUser()->getAttribute('active_microsite');
I've been experiencing the same problem using the plugin sfErrorNotifier.
In my specific case, I noticed a warning was raised:
Warning: ob_start(): function '' not found or invalid function name in /var/www/ncsoft_qa/lib/vendor/symfony/lib/config/sfApplicationConfiguration.class.php on line 155
Notice: ob_start(): failed to create buffer in /var/www/ncsoft_qa/lib/vendor/symfony/lib/config/sfApplicationConfiguration.class.php on line 155
So, checking the file: sfApplicationConfiguration.class.php class, line 155,
I've replaced the ' ' for a null, then the warnings disappears, and also the error!
ob_start(sfConfig::get('sf_compressed') ? 'ob_gzhandler' : ''); bad
ob_start(sfConfig::get('sf_compressed') ? 'ob_gzhandler' : null); good

NServiceBus: Messages handled multiple times

I am at a complete loss as to why I am experiencing this problem. I am new to NServiceBus and have so far set up a dead simple 'server' which listens for messages sent by a web application. The server asks for custom initialisation (IWantCustomInitialization) and uses a custom builder for Castle Windsor 2.5.1. This custom builder is basically a copy of the one that comes with the NServiceBus source code, with two minor changes to move away from methods deprecated in Windsor 2.5.
Note that my code shares the container instance with NServiceBus.
The problem I experience is that every message sent by the web application is processed five (5) times by the server. The log files have five entries for each attempt, with the fifth attempt looking like this:
2011-03-28 16:04:10,326 [Worker.8] DEBUG NServiceBus.Unicast.UnicastBus [] - Calling 'HandleEndMessage' on NServiceBus.SagaPersisters.NHibernate.NHibernateMessageModule
2011-03-28 16:04:10,327 [Worker.8] DEBUG NServiceBus.Unicast.UnicastBus [] - Calling 'HandleEndMessage' on Server.NHibernateSessionMessageModule
2011-03-28 16:04:10,341 [Worker.8] DEBUG NServiceBus.Unicast.UnicastBus [] - Calling 'HandleError' on NServiceBus.SagaPersisters.NHibernate.NHibernateMessageModule
2011-03-28 16:04:10,342 [Worker.8] DEBUG NServiceBus.Unicast.UnicastBus [] - Calling 'HandleError' on Server.NHibernateSessionMessageModule
2011-03-28 16:04:10,344 [Worker.8] ERROR NServiceBus.Unicast.Transport.Msmq.MsmqTransport [] - Message has failed the maximum number of times allowed, ID=80cffd98-a5bd-43e0-a482-a2d96ca42b22\20677.
I have no indication why the message fails, and I don't know where to dig for more information/output.
The configuration 'endpoint' looks like this:
public void Init()
{
container = Windsor.Container;
NServiceBus.Configure.With().CastleWindsor251Builder(container).XmlSerializer().MsmqTransport().IsolationLevel(System.Transactions.IsolationLevel.Unspecified);
var masterInstaller = new NotificationServerInstaller();
masterInstaller.Install(container, null);
}
The message handler is, at this stage, really contrived, and looks like this:
public class NewUserMessageHandler : IHandleMessages<NotifyNewUserMessage>
{
private readonly IGetUserQuery _getUserQuery;
public NewUserMessageHandler(IGetUserQuery getUserQuery)
{
_getUserQuery = getUserQuery;
}
public void Handle(NotifyNewUserMessage message)
{
var result = _getUserQuery.Invoke(new GetUserRequest { Id = new Guid("C10D0684-D25F-4E5E-A347-16F85DB7BFBF") });
Console.WriteLine("New message received: {0}", message.UserSystemId);
}
}
If the first line in the handler method is commented out, the message is processed only once.
I have found some posts/threads on the web (including StackOverflow) which talk about similar issues, notably http://tech.groups.yahoo.com/group/nservicebus/message/5977 and Anyone using Ninject 2.0 as the nServiceBus ObjectBuilder? - but I haven't had any success in making my problem go away.
I'd be most obliged for any help. I'm a n00b at NServiceBus!
NServiceBus isn't handling it multiple times by default it will retry 5 times if an exception occurs, you can set this in a config file. Have you got distributed transactions turned on? Because you are committing to a database and you have an open transaction (the queue transaction) when you open another transaction it will try and upgrade it to a distributed transaction, I think that may be the issue. Have you run with the console app? You should see some out put on there.
I would recommend wrapping the body of the Handle method in a try/catch and add a break point to the catch and see what is wrong.
Once you work it out, remove the try/catch.