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GLYPH<SM590000> Communication for business-critical applications: Some operations within an integration architecture do not require ensured delivery, for example ,  read operations or calls to idempotent services where the caller can retry on failure. The convenience of HTTP is a natural protocol for these types of interaction due to its universal availability across platforms, operating systems, and applications. However, when completing non-idempotent data-changing transactions on business-critical applications, HTTP has limitations that can cause frustration and confusion for your clients, and a damaged reputation for the business. We have all experienced the situation when we are completing an order online when suddenly the order goes into an indeterminate state and it is unclear whether the order has occurred. In a stateless integration architecture based on end to end HTTP ,  recovering from fragile networks and application availability that cause the above situations is challenging if not unfeasible. Messaging technologies such as IBM MQ provide ensured delivery, where situations that can cause an end to end failure are reduced, and there is improved recoverability in these cases. 

GLYPH<SM590000> Hybrid multicloud business critical communication: Within a traditional enterprise with a single data center, your business-critical communication between applications is bound to the data center. As enterprises embrace the cloud, this leads to a hybrid multicloud enterprise with applications hosted across on-premises, public, and private clouds. When communicating between clouds, the network becomes the weak link. Here, reliable cross-cloud messaging is critical, enabling applications within each cloud to confidently write messages locally within their own cloud and know that the messaging framework will solve the problem of reliably getting them to their destination cloud once . 

Figure 3-23 shows multicloud messaging. 

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