Hi Alan, Thanks for the response and apologies for failing to notice you had posted it some days ago (doh!).
Jonathan Halliday has already explained how Red Hat might want to use this API. Well, what he said, essentially! In particular, this model provides a way of ensuring that raw byte data is able to be persisted coherently from Java with the minimal possible overhead. It would be up to client code above this layer to implement structuring mechanisms for how those raw bytes get populated with data and to manage any associated issues regarding atomicity, consistency and isolation (i.e. to provide the A, C and I of ACID to this API's D). The main point of the JEP is to ensure that this such a performant base capability is available for known important cases where that is needed such as, for example, a transaction manager or a distributed cache. If equivalent middleware written in C can use persistent memory to bring the persistent storage tier nearer to the CPU and, hence, lower data durability overheads then we really need an equivalently performant option in Java or risk Java dropping out as a player in those middleware markets. I am glad to hear that other alternatives might be available and would be happy to consider them. However, I'm not sure that this means this option is not still desirable, especially if it is orthogonal to those other alternatives. Most importantly, this one has the advantage that we know it is ready to use and will provide benefits (we have already implemented a journaled transaction log over it with promising results and someone from our messaging team has already been looking into using it to persist log messages). Indeed, we also know we can use it to provide a base for supporting all the use cases addressed by Intel's libpmem and available to C programmers, e.g. a block store, simply by implementing Java client libraries that provide managed access to the persistent buffer along the same lines as the Intel C libraries. I'm afraid I am not familiar with Panama 'scopes' and 'pointers' so I can't really compare options here. Can you point me at any info that explains what those terms mean and how it might be possible to use them to access off-heap, persistent data. regards, Andrew Dinn ----------- Senior Principal Software Engineer Red Hat UK Ltd Registered in England and Wales under Company Registration No. 03798903 Directors: Michael Cunningham, Michael ("Mike") O'Neill, Eric Shander