Chronicle Map vs market data distributor,

Question

I am trying to understand the concept of Market data distributor(MDD) which comes with Chronicle Enterprise.

In my opinion both Map and MDD always holds the latest value of a key and since chronicle Map is implementation of Concurrent Hashmap you certainly don't have any concurrency factor.

What advantages are there using MDD over chronicle Map. All I understood is, it gives better latency for Contended keys. Is there anything else which can be a primary factor for using MDD over Map ?

Answer 1

It's hard to compare apples to oranges. MDD and Map are two completely different and independent products, with completely different purposes.

• MDD is designed to distribute rapidly changing data to consumers (referred to as readers). This solution provides low latency market data distribution, based upon a subscription, to a number of processes on the same host. The subscription takes a key, which for market data is likely to be an instrument identifier. The implementation also has the added requirement that reads should not block writes and vice versa.
• Map doesn't provide subscription mechanism, does block readers on writes, and its performance characteristics are very much different.