I wanted to make the cepheus cep receive incoming events from the context broker rather than the cepheus broker but then I checked the cepheus-cep logs when I uploaded the config.json file and found that it doesn't subscribe to the entities in the context broker as there's no subscription launched. Also when I tried send the subscription manually on behalf of the cepheus-cep and started to send messages to the entities in the context broker, the Cepheus-cep treated the notifications as mere post request not as eventin messages that should be processed and it displays a message stating "POST method not supported".
So, what could be the solution for both issues regarding the Cep subscription to context broker and the manual subscription I made?
Related
I want to implement a connected OAuth app in Salesforce which should trigger push events in case some entities changed, for example an opportunity was closed.
Zapier implemented something similar
https://zapier.com/apps/salesforce/integrations/webhook
Could not find something I need which is a simple way to subscribe to entity changes using the OAuth client's token and passing a webhook endpoint. I read about apex callouts, streaming API and outbound messages.
Yeah, we solved this exact problem at Fusebit and I can help you understand the process as well.
Typically speaking here's what you need to do:
Create triggers on the Salesforce Objects you want to get updates for
Upload Apex class that will send an outgoing message to a pre-determined URL
Enable Remote Site Setting for the Domain you want to send the message to
Add in Secret Verification (or other auth method) to prevent spamming of your external URL
If you're leveraging javascript, then you can use the jsforce sdk & salesforce tooling API to push the code into the salesforce instance AFTER the Auth flow has occurred AND on Salesforce Instances that have API access enabled (typically - this is enterprise and above OR professional with API enabled).
This will be helpful for you to look through: https://jamesward.com/2014/06/30/create-webhooks-on-salesforce-com/
FYI - Zapier's webhooks implementation is actually polling every 15 minutes, instead of real-time incoming events.
In which programming language?
For consuming outbound messages you just need to be able to accept an XML message and send back "Ack" message to acknowledge receiving, otherwise SF will keep trying to resend it for 24h.
For consuming platform events / streaming API / Change Data Capture (CDC) you'll need to raise the event in SF (Platform Event you could raise from code, flow, process builder, CDC would happen automatically, you just tell it which objects it should track).
And then in client app you'd need to login to SF (SOAP or REST API), subscribe to channel (any library that supports cometd should be fine). Have you seen "EMP Connector", mentioned for example in https://trailhead.salesforce.com/en/content/learn/modules/change-data-capture/subscribe-to-events?trail_id=architect-solutions-with-the-right-api ?
Picking right messaging way is an art, there's free course that can help: https://trailhead.salesforce.com/en/content/learn/trails/architect-solutions-with-the-right-api
And pretty awesome PDF if you want to study for certification: https://resources.docs.salesforce.com/sfdc/pdf/integration_patterns_and_practices.pdf
I have watch/subscribed to the topic using the following code.
request = {
'labelIds': ['INBOX'],
'topicName': 'projects/myproject/topics/mytopic'
}
gmail.users().watch(userId='me', body=request).execute()
How can I get the status of the topic at any given point in time? The problem is, sometimes I am not getting the push from Gmail for any incoming emails.
From the Cloud Pub/Sub perspective, if you want to check on the status of messages, you could look at metrics via Stackdriver. There are many Cloud Pub/Sub metrics that are available. You can create graphs on any of the metrics that will be mentioned later by going to Stackdriver, creating a new dashboard, clicking on "Add Chart," and then typing in the name of the metric in the "Find resource type and metric box:
The first thing you have to determine is whether the issue is on the publish side (from Gmail into your topic) or on the subscribe side (from the subscription to your push endpoint). To determine if the topic is receiving messages, look at the topic/send_message_operation_count metric. This should be non-zero at points where messages were sent from Gmail to the topic. If it is always zero, then it is likely that the connection from Gmail to Cloud Pub/Sub is not set up properly, e.g., you need to grant publish rights to the topic. Note that results are delayed, so from the time you expect a message to have been sent to when it would be reflected on the graph could be up to 5 minutes.
If the messages are successfully being sent to Pub/Sub, then you'll want to see the status of attempts to receive those messages. If your subscription is a push subscription, then you'll want to look at subscription/push_request_count for the subscription. Results are grouped by response code. If the responses are in the 400 or 500 ranges, then Cloud Pub/Sub is attempting to deliver messages to your subscriber, but the subscriber is returning errors. In this case, it is likely an issue with your subscriber itself.
If you are using the Cloud Pub/Sub client libraries, then you'll want to look at properties like subscription/streaming_pull_message_operation_count to determine if your subscriber is managing to try to fetch messages for a subscription. If you are calling the pull method directly in your subscriber, then you'll want to look at subscription/pull_message_operation_count to see if there are pull requests returning successfully to your subscriber.
If the metrics for push, pull, or streaming pull indicate errors, that should help to narrow down the problem. If there are no requests at all, then it indicates that the subscribers may not There could be permission problems, e.g., the subscriber is running as a user that doesn't have permission to read from subscriptions.
I have a micro-service which subscribes to a topic in WebSphere MQ. The subscription is managed and durable. I explicitly set the subscription name, so that it can be used to connect back to the queue, after recovering from any micro service failure. The subscription works as expected.
But I might have to scale up the micro service and run multiple instances. In this case I will end up with having multiple consumers to the same topic. But here it fails with error 2429 : MQRC_SUBSCRIPTION_IN_USE. I am not able to run more than one consumer to the topic subscription. Note : A message should be sent only to one of the consumers.
Any thought ?
IBM Websphere Version : 7.5
I use the C-client API to connect to the MQ.
When using a subscriber what you describe is only supported via the IBM MQ Classes for JMS API. In v7.0 and later you can use Cloned subscriptions (this is a IBM extension to the JMS spec), in addition in MQ v8.0 and later you can alternately use Shared subscriptions which is part of the JMS 2.0 spec. With these two options, multiple subscribers can be connected to the same subscription and only one of them will receive each published message.
UPDATE 20170710
According to this APAR IV96489: XMS.NET DOESN'T ALLOW SHARED SUBSCRIPTIONS EVEN WHEN CLONESUP PROPERTY IS ENABLED, XMS.NET is also supposed to support Cloned subscriptions but due to a defect this is will not be supported until 8.0.0.8 or 9.0.0.2 or if you request the IFIX for the APAR above.
You can accomplish something similar with other APIs like C by converting your micro-service to get from a queue instead of subscribing to a topic.
To get the published messages to the queue you have two options:
Setup a administrative subscription on the queue manager. You can do this a few different ways. The example below would be using a MQSC command.
DEFINE SUB('XYZ') TOPICSTR('SOME/TOPIC') DEST(SOME.QUEUE)
Create a utility app that can open a queue and create a durable subscription with that provided queue, the only purpose of this app would be to subscribe and unsubscribe a provided queue, it would not be used to consume any of the published messages.
Using the above method, each published message can only be read (GET) from the queue by one process or thread.
In my Apache Camel application, I have a very simple route:
from("aws-sqs://...")
.aggregate(constant(true), new AggregationStrategy())
.completionSize(100)
.to("SEND_AGGREGATE_VIA_HTTP");
That is, it takes messages from AWS SQS, groups them in batches of 100, and sends them via HTTP somewhere.
Exchanges with messages from SQS are completed successfully on getting into the aggregate stage, and SqsConsumer deletes them from the queue at this point.
The problem is that something might happen with an aggregated exchange (it might be delivered with an error), and messages will be lost. I would really like these original exchanges to be completed successfully (messages to be deleted from a queue) only when an aggregated exchange they're in is also completed successfully (a batch of messages is delivered). Is there a way to do this?
Thank you.
You could set deleteAfterRead to false and manually delete the messages after you've sent them to you HTTP endpoint; You could use a bean or a processor and send the proper SQS delete requests through the AWS SDK library. It's a workaround, granted, but I don't see a better way of doing it.
I created a working Google Channel AP and now I would like to send a message to all clients.
I have two servlets. The first creates the channel and tells the clients the userid and token. The second one is called by an http post and should send the message.
To send a message to a client, I use:
channelService.sendMessage(new ChannelMessage(channelUserId, "This is a server message!"));
This sends the message just to one client. How could I send this to all?
Have I to store every Id which I use to create a channel and send the message for every id? How could I pass the Ids to the second servlet?
Using Channel API it is not possible to create one channel and then having many subscribers to it. The server creates a unique channel for individual JavaScript clients, so if you have the same Client ID the messages will be received only by one.
If you want to send the same message to multiple clients, in short, you will have to keep a track of active clients and send the same message to all of them.
If that approach sounds scary and messy, consider using PubNub for your push notification messages, where you can easily create one channel and have many subscribers. To make it run on Google App Engine is not that hard, since they support almost any platform or device.
I know this is an old question, but I just finished an open source project that uses the Channel API to implement a publish/subscribe model, i.e. you can have multiple users subscribe to a single topic, and then all those subscribers will be notified when anyone publishes a message to the topic. It also has some nice features like automatic message persistence if desired, and "return receipts", where a subscriber can be notified whenever OTHER subscribers receive that message. See https://github.com/adevine/gaewebpubsub#gae-web-pubsub. Licensed under Apache 2.0 license.