We have released a 2 minute tech tip through the Oracle Technology Network (OTN) which talks through the creation of a simple end to end integration using Oracle’s Integration Cloud Service (ICS).
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ICS pricing is based on two aspects – the number of connections and the number of messages processed. But what constitutes a connection? What happens if I exceed the number of messages or connections?
In the second release of 2017 (17.2.5) ICS will introduce the capability of importing and using custom functions. These functions are created using JavaScript and can be used in transformations, expressions and as a action in Orchestrations. In this definitive guide we will go through all ins and outs of this new capability.
Custom functions – a new pillar of ICS
In our book we talked about the pillars of ICS; Connections, Integrations, Lookups, Agents, Adapters and Packages. This release introduced Libraries. A library is a set of Javascript functions. Keep in mind that the JavaScript functions are running server-side so some browser/client-side capabilities/APIs are not available. Functions can’t be created within ICS, but can be uploaded as part of a library in both JS and JAR file (collection of JS files) formats.
Enriching an integration from data in a database or DBaaS (Database as a Service) is not an unusual requirement. Many integration use cases today need to access a database that is on-premises. The means to connect to the database is fairly obvious – the connection agent. Our book goes into a lot more detail as to why that is, and the implications of using database connections.
However when it comes to Oracle’s DBaaS a service it would be very easy to assume that given that you’re using two different parts of Oracle’s PaaS that it would be straight forward to connect the two together without an agent. However, at least today whether its on-premises or DBaaS you need to use a connection agent. This does mean that you’ll need an IaaS node to host the connection agent.
This quirk is driven by the fact that there are some scenarios that this does actually make sense. For example – the Oracle domains need to have a high level of isolation, so when the DBaaS is in another domain then the decoupling via the agent makes sense. When your database is in a different zone of the cloud – then you’re running DB calls across what is effectively a wide are network – not good.
The question of conditional mapping comes up regularly on the ICS part of community.oracle.com which prompted us to write this blog. So if you want the output of an integration in element X to contain value from element A or B depending upon element C there are a number of answers, each having pros and cons. So let’s look at them before we offer an example of how we would solve the simpler more common problem.. Your choices are ….
- Use the power of XSLT within the mapping,
- Use the conditional option Within a Basic Map Data or an Orchestration pattern,
- Use a custom piece of JavaScript
| XLST | Condition in the flow | Custom Javascript |
| Single path through the integration | Simpler to read and see visually | Can be used either in the condition oer the mapping. Easier to apply than XSLT directly. |
| ICS doesnt make it the easiest to write this, but reading is fairly easy | Easy to visually understand, but means more maintenance effort | Easy to incorporate, but makes the development process multistep |
We have talked about the condition/filtering in the book, and we will tackle the use of JavaScript in its own Definitive Guide, so let’s look at the XSL mapping option, and probably the route that will cover most cases. In many respects this is nothing to do with ICS, and is all about the use of XSLT so you may find it helpful to have an XSLT reference to hand. To this end the following maybe useful:
- W3C – perhaps not the easiest to read, but definitely definitive,
- XMLSchool far more readable but keeps things simple, and focuses on XSLT to create (X)HTML content
In our book we talked about the difference between the agents offered by ICS, namely the Connection and Execution agents. Whilst we differentiated the two, we did focus on the connection agent as this is the type we expect to see used in most cases. However the execution agent still suffers from a level of confusion, and it has been helped by being called ‘ICS on-premises’.
As part of a number of recent conversations the questions and confusion of what the execution agent is and how it works has come up. There is the well known saying ‘a picture is as good as a 1000 words’ which prompted us to develop the diagram below as a power point slide – in its power point form much of the detail is used as an animated build up.
In the last few years Oracle’s iPaaS offerings have progressed significantly from one or two solutions such as Mobile Cloud Service to in excess of 35 offerings. This makes it challenging to decide which product(s) to use. The means for selection depends upon a range of factors including:
- Most suitable licensing model (ICS provides a lower cost of entry than SOA CS as you’re paying by message volumes)
- Development skills and desire to resilience or invest in people (SOA on-premises to SOA CS is easier than a technology change such as ICS)
- The amount of control you have in an environment – JCS offers more control than ACCS for example
The book’s authors presented a brief session on the best practices at a packed Oracle Partner event. The following presentation – shows the material that was presented.
Some of these points are expressed in the book already, others are our Definitive Tips and Guides posts.
Good development practises such as configuration management and naming conventions have been a topic of conversation a number of times recently for us when it comes to ICS. In this post we will look at what configuration management means to ICS and the application of naming standards.
Why Configuration Management?
So why do we need configuration management with a tool such as ICS? The question depends on what stage of the software lifecycle you are, but a few reasons:
- As a developer there have been occasions where we have tried to optimise something and then decided to reverted back to the last secured state in configuration control.
- Deleted something and then regretted it, whilst desktops have the concept of paper basket to recover from, not so in ICS.
- If your providing packages of ICS functionality you may have different released versions – so need to keep master copies of every version available to refer to.
- Sometimes we get ‘configuration drift’ – and therefore need to have a reference point to compare to. This allows us to determine the drift and if it is appropriate to reset an environment. Whilst this may sound less significant, it is enough of a problem for tools like Puppet to incorporate the ability.
- Tracking what versions of integrations are running in a development vs production environment.
In ICS Definitive Guide #2 we looked at the scheduling of integrations and mentioned the possibility of using iCal. In this tip we shall explore advanced iCal facility for defining schedules within ICS.
The iCal format is probably best known for sharing meeting events in tools such as outlook. The format is actually a standard defined by the IETF originally in 1998 (https://www.ietf.org/rfc/rfc2445.txt) and updated several times the latest being 
2015 (https://tools.ietf.org/html/rfc7529). The goal of the definition has been for the purpose of driving standardisation across PIM tools (Personal Information Management) tools which includes Outlook and Thunderbird etc. It is a substantial standard the original document ran to 150 pages, but the section supported by the schweduler’s advanced option purely relates to the reoccurence definition covered by section 4.3.10 of the original RFC, and only takes five pages. If you want to know lots about iCal and the varying revisions then you may find https://icalendar.org/ helpful.
It is worth mentioning that today ICS under the hood exploits Oracle’s Enterprise Scheduler Service (ESS). ESS documentation identifies that it works to the 2445 version of the specification (see here). ESS became a 1st class citizen component with the start of the 12c middleware product stack. As a result, if you see any errors processing an iCal configuration the error codes will reference ESS does.
