Oracle Coherence is very good for a fairly narrow problem area. Building the solution requires investment. The ownership cost might also be considerable. I would recommend making the decision to use Oracle Coherence only with strong technical argumentation and a fair comparison with other alternatives.

My main concern with this product is one of stability, so they need to reduce the number of issues and bugs that there are.

I would rate this solution a five out of ten.

To a similar client looking for advice, I’d say that this is a great product, but you need to pay the price for it. If you are willing to pay the price, you will be satisfied with the product quality. It has more than what you need.

At the enterprise level, if you have all your own data center, Oracle, Coherence, and if you are willing to spend that much money, Oracle is great.

But if you are a small business, going with open source, there are a lot of things available. EH cache is the most popular open source thing with its caching mechanism. That worked well for us on a smaller scale. You need to determine whether that’s going to work for you.

There are multiple products out there. The main determining factors are whether you want to have a local or distributed cache; and whether you want to use it in the Cloud or locally. If you are using it in the Cloud, you can explore multiple options. If you’re use Oracle, they are going to advise you. You are going to need to plan out and implement the caching and system customizations.

Coherence is the most mature product in this space, with the backing of a large support organization.

For a long period, they led the field and are arguably still leading it, but there are other smaller, newer technologies that are catching up fast.

Get a cheaper price and consider your code stack – it fits best with Java-based companies.

You can evaluate Hazelcast, which looks promising.

Do good decisions on serialization and versioning of objects and don't rely on it as the sole source of data, no matter how much energy output it takes to keep its cluster up and running. Rolling out updates can be challenging if you have to write-behind in place. For example, you need to be able to identify that there is nothing waiting before a full shutdown.

Look attentively at other NoSQL solutions, and if they really need a caching solution, then look at Hazelcast.

You need a person with expertise to ramp up quickly. As I’ve mentioned, there is a stiff learning curve, and it can only be avoided with the right person.

It is very important to understand the cache size requirement. Do read the cache size calculation from the documentation to ensure you have enough memory/storage for your data.

Learn distributed computing first. It's not worth using only as a key-value cache. If interrupted business operations is an important consideration, think about deploying the grid along with an application in WebLogic instead of building a separate and independent cluster.

Get a good expert on the technology, because the learning curve can be high.

Take the time to learn it and test all assumptions. For example, I was using push replication [PR] to satisfy a client's disaster recovery [DR] requirement. All of a sudden the primary cluster collapsed - ran out of memory despite having high watermarks configured. As it turned out the DR site connection went down and PR calls started to queue. The high watermark calculation did not know about the PR queue. This was very subtle use case as I didn’t consider what would happen to the PR calls if the other end wasn't available.

Look into Coherence’s features. Get a demo first and evaluate whether you can really make use of this product.

It is a very powerful tool but is very expensive, so if you don´t have enough money, just choose another solution.

My advice to those looking to implement Coherence is to hire someone who has used it extensively in the past, and to create sufficient documentation internally to bring developers up to speed with how to integrate it into their applications. The learning curve to get comfortable with the configuration/deployment/mapping was the single biggest pain point for our project, and greater than I would expect of a third-party integration like this.

The product is great, simple, and easy to use and integrate. See if your infrastructure supports it; if there are ways to make it work. Do a PoC before deciding.

Caching in an important element in order to gain a stable and high-performing system. Therefore, it is important that this product, which is designed to help, should be implemented in the correct way. There are different architectural patterns that can be referred before using cache, best practises regarding cache and invalidation schemes around objects. It is also important to consider the reliability of the object state during usage and also to make sure that its usage is compliant with Oracle’s best practises regarding cache.

Make sure you understand which edition gives which capability, and how that maps to your current needs and your long-term infrastructure evolution. Build wrapper libraries abstracting your actual caching implementation to make it easier for moving across editions and even vendors in the future.

Coherence uses key value pair logic to put data to cache and fetch. If you use immutable object in the cache is it very fast, it takes a nanosecond to put it. It uses PortableObject instead of serialization. PortableObject is lightweight compared to implementing serialization.

Look for open source with better support on monitoring, auditing, and cloud support.

Before you can master Coherence, you must study how a data grid works. So, start learning about common data grid patterns. The next step is Coherence documentation, which is clear, but huge.

My advice would be for Oracle to prepare a database with already existing configurations from clients. This would help future clients to have templates for various solutions already instead of reinventing the wheel. Generally Oracle fails at this chapter as opposed to open source solutions. It is very painful to start from scratch with little or no concrete solutions posted online (full solutions with commercial value).

You can go ahead with this product blindly if you are looking for a memory grid kind of solution. The license is there for sure.

Invest in your network if you use Coherence cluster. Serious!

Oracle Coherence is a very good product which helps to create internet-scale applications using a high-performance grid.

First compare the product to the more open source competitors, like Apache Ignite and Hazelcast.