* As per definition of API by Mulesoft , it is Application Programming Interface using HTTP-based protocols. Non-HTTP-based programmatic interfaces are not APIs.
* HTTP-based programmatic interfaces are APIs even if they don't use REST or JSON. Hence implementation based on Java RMI, CORBA/IIOP, raw TCP/IP interfaces are not API's as they are not using HTTP.
* One more thing to note is FTP was not built to be secure. It is generally considered to be an insecure protocol because it relies on clear-text usernames and passwords for authentication and does not use encryption.
* Data sent via FTP is vulnerable to sniffing, spoofing, and brute force attacks, among other basic attack methods.
Considering the above points only correct option is
-XML over ActiveMQ
- XML over SFTP
- XML/REST over HTTPS

* JMS (Java Message Service): JMS is a robust messaging standard that supports reliable and asynchronous communication. It allows message producers and consumers to exchange messages via a common message broker.
* Transactions with Automatic Acknowledgements: Utilizing JMS transactions ensures that messages are processed reliably. The automatic acknowledgement mode means that once the consumer receives the message, it acknowledges the broker automatically, ensuring that no messages are lost.
* Performance and Reliability: JMS transactions offer both high performance and reliability. By enabling transactions, each message processing step can be committed or rolled back, ensuring data integrity.
* Cross-Cluster Messaging: For a stock trading company dealing with millions of trades, using JMS transactions allows for consistent and reliable message delivery across different clusters in their network. This approach is more suitable compared to non-transactional or VM queues due to the scale and reliability requirements.
* Event-Driven APIs: The APIs can leverage the transactional nature of JMS to ensure that messages exchanged between different services are reliable and can recover gracefully from failures.
References:
* MuleSoft Documentation on JMS Connector: MuleSoft JMS Connector
* JMS 2.0 Specification: Oracle JMS 2.0

* Setting a transaction timeout for the Bitronix transaction manager
Set the transaction timeout either
- In wrapper.conf
- In CloudHub in the Properties tab of the Mule application deployment
The default is 60 secs. It is defined as
mule.bitronix.transactiontimeout = 120
* This property defines the timeout for each transaction created for this manager.
If the transaction has not terminated before the timeout expires it will be automatically rolled back.
--------------------------------------------------------------------------------------------------------------------- Additional Info around Transaction Management:
Bitronix is available as the XA transaction manager for Mule applications To use Bitronix, declare it as a global configuration element in the Mule application
<bti:transaction-manager />
Each Mule runtime can have only one instance of a Bitronix transaction manager, which is shared by all Mule applications For customer-hosted deployments, define the XA transaction manager in a Mule domain
- Then share this global element among all Mule applications in the Mule runtime Graphical user interface, table Description automatically generated with medium confidence