The 4D Community is one of the reason of the success of 4D. Brent Raymond, Senior Software Architect from the Art Institute of Chicago, presents at 4D Summit Portland 2016 the 4DMethod user group: its role, what topics are discussed, how meetings are held…
Cache management is actually a key element of the database management, Laurent Ribardière presents at 4D Summit Portland 2016 the new cache manager he implemented in the 4D v16 64-bit version.
Before watching the technical presentation with details about the implementation, we recommend to start with these two blog posts, describing the feature benefit itself:
64-bit is the way where everybody needs to go. 64-bit allows you to take advantage of the power of the 64-bit machines and of the latest native system features for your business application.
With 4D v16 R2, 4D has reached a major milestone as 4D Developer Edition and the 4D Volume Desktop Windows 64-bit are now released as “Final” and are thus ready for production.
Start early, use it now and share your feedback through in the beta version forum from 4D Forums!
If your users are running your application as a virtualized application, chances are high they use VMWare vSphere (Hypervisor ESXi) and are using snapshots.
4D v16 R2 will automatically install a VSS writer service. VSS stands here for Volume Shadow Copy Service. When the VMWare administrator starts a snapshot, VMWare informs the guest, which informs the VSS writer, which will inform 4D Server to flush the cache and wait for one second. Then it will inform the OS that the .4DD, .4DIndx and .Journal files belong together and must be snapshot at the same time. The OS will handle this and 4D Server can continue to handle client requests. The “freeze” lasts around a second, usually not even noticed by connected users.
4D v16 introduced a new fully optimized cache manager for the 64-bit product line. 4D v16 R2 is giving power to our advanced 4D developers to take control by themselves!
The cache manager internal algorithm is based on a priority concept associated to each object type to store in the cache memory. By default, the cache manager algorithm assigns a higher priority value for an index than for records. And recently used objects (records or indexes) have a higher priority to remain in the cache than objects that have not been used in the last two days, etc…
I am pleased to announce that the beta testing of 4D v16 R2 starts today!
4D v16 R2 delivers the final version of Altura-free 4D Developer Edition Windows 64-bit as well as great improvements, among other things, as listed below:
- Better integration into the enterprise with Virtual Machine Snapshots Support
- More control and higher flexibility for the developer: Cache Manager priority control, new programmatic possibilities for list boxes, search in array in objects using linked arguments,…
- Improved user experience: horizontal ruler in 4D Write Pro, cross table in Quick Report 64-bit editor as well as a revisited Find in Design dialog.
The 4D v16 version has definitely been designed for better performance and scalability. In addition to major features like preemptive multi-threading, 4D v16 64-bit is embedding a brand new cache manager for a optimized handling of objects in cache memory avoiding any fragmentation issues.
The new cache manager improves the usage of very large cache for modern computers (with 64 or even 128 GB of Cache) allowing to take advantage of low RAM prices to have even large databases fully in memory. It also improves the situation of small cache size with very large data files, by decreasing the amount of unloading memory with increased support of priorities for data objects to be hold or released from cache.
From 4D v16, you can define at design phase the way a 4D Write Pro document will be displayed in a 4D Write Pro area. Without writing a single line of code, you can define several view attributes such as the resolution, zoom, page view mode. Advanced properties are also available to define whether you want to show 4D expressions or values for instance. Again no code to write, just a checkbox and it’s done.
With 4D v16, 4D Write Pro is now providing a higher level of protection regarding the evaluation of 4D expressions in documents.
Developers can now fully rely on 4D for checking the evaluation of these expressions. By doing so, end-user machines and databases will be automatically protected from any possible side effects.
A valid 4D expression can be a field, a variable, a 4D command, a statement returning a value, a project method, and so on.
Starting with 4D v16, “unsafe” 4D expressions will no longer be evaluated and an error will be displayed instead.
On the way to provide Windows 64-bit version of the 4D product line we reached a major milestone, an Altura-free version. Altura is a library to emulate MacOS functionality on Windows, which was used to help plug-in developers to provide their products on Windows.
Although internally 4D for the most part did not use Altura any longer for a while, it was still deeply integrated to provide the functionality for 3rd party plug-ins.