App Connect

When we create REST API in ACE or IIB why it will create 3 additional instances by default? Is this related with the common CRUD Methods (POST, PUT, GET & DELETE)? If that is the case if we have only one METHOD example GET in the REST API will all the additional instance will be available for the GET method?

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Abrha Weldetinsae
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Hi Abrha,

The bar file which gets generated from the REST API does carries  additional instance count  as 3 for it. This value can be changed at the bar file level as needed anywhere from 0 to 256. 

When REST API is created in IIB or ACE after importing swagger file, then the message flow gets created with one HTTP input node in it.
Then the swagger can have multiple operations inside it like GET, POST, DELETE etc. These multiple operations are implemented as subflows.
The count of the subflows (operations) is not relevant to the number of additional instances (because they are not carrying any input node in them).
what matters is the: -
1) number of input nodes the flows is having. Which is one in case of REST API i.e. HTTP input node.
2) the number of additional instances defined at the bar file/message flow level/node level. By default the addition instance count is 0.
Check these links as to how the maximum number of threads get counted: - 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-level 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-node-level 


------------------------------
Gursharan Singh
------------------------------

Original Message:
Sent: Thu April 28, 2022 10:28 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

When we create REST API in ACE or IIB why it will create 3 additional instances by default? Is this related with the common CRUD Methods (POST, PUT, GET & DELETE)? If that is the case if we have only one METHOD example GET in the REST API will all the additional instance will be available for the GET method?

------------------------------
Abrha Weldetinsae
------------------------------

Original Message:
Sent: 4/29/2022 3:49:00 AM
From: Gursharan Singh
Subject: RE: Why REST API in ACE or IIB have 3 additional instances by default?

Hi Abrha,
The REST API doesn't have 3 additional instance by default unless it is explicitly mentioned in the additional instance count.

When REST API is created in IIB or ACE after importing swagger file, then the message flow gets created with one HTTP input node in it.
Then the swagger can have multiple operations inside it like GET, POST, DELETE etc. These multiple operations are implemented as subflows.
The count of the subflows (operations) is not relevant to the number of additional instances (because they are not carrying any input node in them).
what matters is the: -
1) number of input nodes the flows is having. Which is one in case of REST API i.e. HTTP input node.
2) the number of additional instances defined at the bar file/message flow level/node level. By default the addition instance count is 0.
Check these links as to how the maximum number of threads get counted: - 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-level 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-node-level 
Thanks,
Gursharan Singh

------------------------------
Gursharan Singh
------------------------------

Original Message:
Sent: Thu April 28, 2022 10:28 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

When we create REST API in ACE or IIB why it will create 3 additional instances by default? Is this related with the common CRUD Methods (POST, PUT, GET & DELETE)? If that is the case if we have only one METHOD example GET in the REST API will all the additional instance will be available for the GET method?

------------------------------
Abrha Weldetinsae
------------------------------

Hi Singh

I just tried it in ace 12.0.4.0 and I also have the 3 additional instances.
I have 3 operations and 1 input node. After bar creation I see the following property

gen.TestAPI#additionalInstances = 3​

------------------------------
Regards
Matthias Blomme
------------------------------

Original Message:
Sent: Fri April 29, 2022 12:27 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

Hi Singh,

Thank you for the reply. 

Did you get a chance to create a REST API from swagger and check? Even i tried to import some of the REST API from the Toolkit tutorials and it behaves the same for me.

Kind Regards,

Abrha Weldetinsae

Original Message:
Sent: 4/29/2022 3:49:00 AM
From: Gursharan Singh
Subject: RE: Why REST API in ACE or IIB have 3 additional instances by default?

Hi Abrha,
The REST API doesn't have 3 additional instance by default unless it is explicitly mentioned in the additional instance count.

When REST API is created in IIB or ACE after importing swagger file, then the message flow gets created with one HTTP input node in it.
Then the swagger can have multiple operations inside it like GET, POST, DELETE etc. These multiple operations are implemented as subflows.
The count of the subflows (operations) is not relevant to the number of additional instances (because they are not carrying any input node in them).
what matters is the: -
1) number of input nodes the flows is having. Which is one in case of REST API i.e. HTTP input node.
2) the number of additional instances defined at the bar file/message flow level/node level. By default the addition instance count is 0.
Check these links as to how the maximum number of threads get counted: - 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-level 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-node-level 
Thanks,
Gursharan Singh

------------------------------
Gursharan Singh

Original Message:
Sent: Thu April 28, 2022 10:28 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

When we create REST API in ACE or IIB why it will create 3 additional instances by default? Is this related with the common CRUD Methods (POST, PUT, GET & DELETE)? If that is the case if we have only one METHOD example GET in the REST API will all the additional instance will be available for the GET method?

------------------------------
Abrha Weldetinsae
------------------------------

Hi Matthias,
The bar file created for REST API does carry additional instance of 3 (as default). This additional instance count is not related to the number of operations which are there in the REST API; it is just default value. If the REST API was carrying one operation or say10 operations in it, even then at the bar file level you will see additional instance count of 3. 
REST APIs are meant handle multiple parallel invocations, so this behavior of having additional instance count of 3 as default (and not 0) is justified.


------------------------------
Gursharan Singh
------------------------------

Original Message:
Sent: Thu May 19, 2022 08:43 AM
From: Matthias Blomme
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

Hi Singh

I just tried it in ace 12.0.4.0 and I also have the 3 additional instances.
I have 3 operations and 1 input node. After bar creation I see the following property

gen.TestAPI#additionalInstances = 3​

------------------------------
Regards
Matthias Blomme

Original Message:
Sent: Fri April 29, 2022 12:27 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

Hi Singh,

Thank you for the reply. 

Did you get a chance to create a REST API from swagger and check? Even i tried to import some of the REST API from the Toolkit tutorials and it behaves the same for me.

Kind Regards,

Abrha Weldetinsae

Original Message:
Sent: 4/29/2022 3:49:00 AM
From: Gursharan Singh
Subject: RE: Why REST API in ACE or IIB have 3 additional instances by default?

Hi Abrha,
The REST API doesn't have 3 additional instance by default unless it is explicitly mentioned in the additional instance count.

When REST API is created in IIB or ACE after importing swagger file, then the message flow gets created with one HTTP input node in it.
Then the swagger can have multiple operations inside it like GET, POST, DELETE etc. These multiple operations are implemented as subflows.
The count of the subflows (operations) is not relevant to the number of additional instances (because they are not carrying any input node in them).
what matters is the: -
1) number of input nodes the flows is having. Which is one in case of REST API i.e. HTTP input node.
2) the number of additional instances defined at the bar file/message flow level/node level. By default the addition instance count is 0.
Check these links as to how the maximum number of threads get counted: - 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-level 
https://www.ibm.com/docs/en/integration-bus/9.0.0?topic=subflows-adding-additional-instances-message-flow-node-level 
Thanks,
Gursharan Singh

------------------------------
Gursharan Singh

Original Message:
Sent: Thu April 28, 2022 10:28 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

When we create REST API in ACE or IIB why it will create 3 additional instances by default? Is this related with the common CRUD Methods (POST, PUT, GET & DELETE)? If that is the case if we have only one METHOD example GET in the REST API will all the additional instance will be available for the GET method?

------------------------------
Abrha Weldetinsae
------------------------------

Original Message:
Sent: 4/28/2022 10:28:00 PM
From: Abrha Weldetinsae
Subject: Why REST API in ACE or IIB have 3 additional instances by default?

When we create REST API in ACE or IIB why it will create 3 additional instances by default? Is this related with the common CRUD Methods (POST, PUT, GET & DELETE)? If that is the case if we have only one METHOD example GET in the REST API will all the additional instance will be available for the GET method?

------------------------------
Abrha Weldetinsae
------------------------------