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| uncodead |
 Posted: Thu Jul 20, 2017 12:38 pm Post subject: Pub/Sub - Publish without using an MQInput/Output |
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Novice
Joined: 28 Mar 2017
Posts: 10
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In a REST application, i need to publish a message in this flow:
RESTApi -> ComputeNode -> Publication -> ...
Can I publish without using an MQInput / Output? |
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| Vitor |
| Posted: Thu Jul 20, 2017 1:32 pm Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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What does the "Subscription Point" property of the Publication node do?
How would you get anything out of a broker with an MQInput node?
If you in fact mean "Can I subscribe to a publication without using an MQInput node?" then no, IIB lacks a Subscription node. It needs to pick up publications from a queue but can then interpret all of the publication details (Topic name and so forth) as if it had subscribed.
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Insanity is the best defence. |
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| uncodead |
| Posted: Thu Jul 20, 2017 1:44 pm Post subject: |
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Novice
Joined: 28 Mar 2017
Posts: 10
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| Vitor wrote: |
What does the "Subscription Point" property of the Publication node do?
How would you get anything out of a broker with an MQInput node?
If you in fact mean "Can I subscribe to a publication without using an MQInput node?" then no, IIB lacks a Subscription node. It needs to pick up publications from a queue but can then interpret all of the publication details (Topic name and so forth) as if it had subscribed. |
My scenario is the following:
I get a rest request and I need to post the received message to a topic. But I would not want to put the message in a queue and then publish it using: MQInput node -> Publication node. |
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| mqjeff |
| Posted: Thu Jul 20, 2017 3:01 pm Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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So you need
1) A node to receive an HTTP REST request
2) A node to transform your data
3) A node to publish a message.
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| uncodead |
| Posted: Thu Jul 20, 2017 3:40 pm Post subject: |
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Novice
Joined: 28 Mar 2017
Posts: 10
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| mqjeff wrote: |
So you need
1) A node to receive an HTTP REST request
2) A node to transform your data
3) A node to publish a message. |
the question is how can i do it in esql only |
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| mqjeff |
| Posted: Thu Jul 20, 2017 6:00 pm Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| uncodead wrote: |
| mqjeff wrote: |
So you need
1) A node to receive an HTTP REST request
2) A node to transform your data
3) A node to publish a message. |
the question is how can i do it in esql only |
Do what? Publish a message?
Use the propagate statement, that sends the message to an output node.
You haven't even said what transport you are using to do pub/sub on. MQ? MQLight? MQTT? Kafka? RabbitMQ? JMS? Unknown raw TCP format? Homing Pigeons?
So, yes, you can publish a message without using an MQInput node and an MQOutput node, or even a Publication node...
But ESQL doesn't let you directly send data to an external transport.
So if you need to publish a message, you need a node to publish it.
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| uncodead |
| Posted: Thu Jul 20, 2017 6:19 pm Post subject: |
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Novice
Joined: 28 Mar 2017
Posts: 10
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| mqjeff wrote: |
| uncodead wrote: |
| mqjeff wrote: |
So you need
1) A node to receive an HTTP REST request
2) A node to transform your data
3) A node to publish a message. |
the question is how can i do it in esql only |
Do what? Publish a message?
Use the propagate statement, that sends the message to an output node.
You haven't even said what transport you are using to do pub/sub on. MQ? MQLight? MQTT? Kafka? RabbitMQ? JMS? Unknown raw TCP format? Homing Pigeons?
So, yes, you can publish a message without using an MQInput node and an MQOutput node, or even a Publication node...
But ESQL doesn't let you directly send data to an external transport.
So if you need to publish a message, you need a node to publish it. |
ok, i'm using MQ, i need to know what i need to do in esql to publish the message to a topic. |
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| fjb_saper |
| Posted: Thu Jul 20, 2017 8:16 pm Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| uncodead wrote: |
ok, i'm using MQ, i need to know what i need to do in esql to publish the message to a topic. |
You need to have an RFH2 header on the message, specifying the topic you want to publish to and you need to make your next node be the publish node.
If you want to know if you got published, make it a request message, and read the return code from the publish, in the RFH2 of the reply message...
Have fun 
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| smdavies99 |
| Posted: Fri Jul 21, 2017 12:30 am Post subject: |
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Jedi Council
Joined: 10 Feb 2003
Posts: 6076
Location: Somewhere over the Rainbow this side of Never-never land.
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| fjb_saper wrote: |
| uncodead wrote: |
ok, i'm using MQ, i need to know what i need to do in esql to publish the message to a topic. |
You need to have an RFH2 header on the message, specifying the topic you want to publish to and you need to make your next node be the publish node.
If you want to know if you got published, make it a request message, and read the return code from the publish, in the RFH2 of the reply message...
Have fun |
Or simply write the message to a correctly configured ALIAS Queue. 
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Every time you reinvent the wheel the more square it gets (anon). If in doubt think and investigate before you ask silly questions. |
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| timber |
| Posted: Fri Jul 21, 2017 3:00 am Post subject: |
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Grand Master
Joined: 25 Aug 2015
Posts: 1292
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| Quote: |
| the question is how can i do it in esql only |
You cannot. You have to use a Publication node. Why do you want to do it in ESQL only? |
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| mqjeff |
| Posted: Fri Jul 21, 2017 3:48 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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In IIB v9, you do not need an MQRFH2
Again.
ESQL does not let you send data to any transport.
You can call procedures in other languages. Those other languages can send data to different transports.
It's very poor design to use, for example, a JavaCompute node to publish a message to an MQ topic using JMS. Or use any other language to send data to any transport that already has an Output node for that.
It's a very poor design.
Use the product. Stop trying to skip steps and make your code much harder to read.
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| Android 23 |
| Posted: Fri Jul 28, 2017 1:43 am Post subject: |
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Apprentice
Joined: 27 Mar 2017
Posts: 38
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| Quote: |
Can I publish without using an MQInput / Output? |
Yes, you publish the message because Pub/Sub is not related to the message flow.
| Quote: |
My scenario is the following:
I get a rest request and I need to post the received message to a topic. But I would not want to put the message in a queue and then publish it using: MQInput node -> Publication node. |
No need of MQ nodes because we directly subscribe to the topic in it.
And the message moves into Subscription queue.
Thanks & Regards
Android 23 |
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| Vitor |
| Posted: Fri Jul 28, 2017 5:02 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| Android 23 wrote: |
No need of MQ nodes because we directly subscribe to the topic in it.
And the message moves into Subscription queue. |
I'll bite - how are you getting IIB to "directly subscribe" to the topic without using any of the MQ nodes?
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Honesty is the best policy.
Insanity is the best defence. |
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| mqjeff |
| Posted: Fri Jul 28, 2017 5:11 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| Vitor wrote: |
| Android 23 wrote: |
No need of MQ nodes because we directly subscribe to the topic in it.
And the message moves into Subscription queue. |
I'll bite - how are you getting IIB to "directly subscribe" to the topic without using any of the MQ nodes? |
JMSInput...
KafkaConsume...
LoopBBackRequest, with an appropriate Loop Back connector...
MQTTInput
.NETinput (for MSMQ)....
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| zpat |
| Posted: Fri Jul 28, 2017 7:02 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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Avoidance of MQ is not exactly a virtue.
You get a MQ license with broker and it is by far the most proven and reliable messaging product to use. Pub/sub is built-in, support is excellent and it's widely used by large companies. It has been here 20 years and should be here well into the future (unlike some).
Apparently it even has a helpful user community.
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Well, I don't think there is any question about it. It can only be attributable to human error. This sort of thing has cropped up before, and it has always been due to human error. |
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