By: Gregory Keller
Abstract: Brief paper providing guidance on planning for the growth of Repo's database
This document is intended to serve as a hardware sizing guide for the ER/Studio. It covers the ER/Studio Repository application, the ER/Studio Repository database, the ER/Studio client, and the License Server. This information here supplements that in the ER/Studio Installation Guide and the ER/Studio help. The objective of this document is twofold: first, to provide a top-down sizing approach that is reliable and easy to follow; and second, to provide a conceptual basis for sizing ER/Studio and its associated software components.
ER/Studio Repository Hardware Configuration
Embarcadero does not explicitly support virtual implementations, however we have a number of successful examples inside and outside of Embarcadero, of ER/Studio repositories (and license servers) running within a VMWare environment. It is a fact of life that virtual configurations will carry both a CPU and a memory overhead. Embarcadero does not currently have any benchmarks available to quantify the virtualization overhead for ER/Studio on different virtualization platforms. Vendors generally have their own guidelines, and customers who make extensive use of virtualization will have probably made their own measurements.
Application, Database, and Desktop Location
Collocating the ER/Studio Repository application and the ER/Studio Repository database does enhance overall repository performance. In installations with stringent performance requirements, these components should be not merely in the same physical location (i.e. data center), but if possible on the same server.
Desktop performance is similarly dependent upon the latency and bandwidth of the network between the ER/Studio desktop and the ER/Studio Repository server.
It is recommended that regular users of ER/Studio have at least 1 GB of RAM on their client machines. While 512 MB is enough to effectively navigate a typical diagram, users commonly like to have multiple models open at once (to say nothing of multiple applications!) Additionally, certain operations, such as Compare & Merge, can consume quite a lot of desktop memory, particularly when large models are being compared. Many repository activities require an implicit compare between the version of the model stored in the repository, and that which is on the desktop.
General Recommendation: 1 GB RAM
Floating-license implementations of ER/Studio use an additional software component called the Embarcadero License Server. This lightweight software package provides centralized management of shared ER/Studio licenses, as well as some reporting capabilities around license usage. The License Server can be installed on a separate server from the ER/Studio Repository. Commonly it is installed on the same server as the Repository. Overhead is not significant, except during very small windows where reports are being generated.
The ER/Studio Install Guide provides further detail on sizing and configuration, including tables with bottom-up estimation guidelines, and matrices of supported platforms and minimum requirements for those platforms. Beyond what is noted therein, it is useful to know that branches take up approximately the same amount of space in the repository as the parent diagram, whereas named releases take up approximately 20 – 30% as much space as that of the diagram.
For implementations having more than 50 diagrams, it may be useful to supplement the top-down approach presented here with a more detailed bottom-up sizing, to arrive at a more accurate estimate for Repository database disk utilization. That said, it may be cheaper to simply allocate a few extra GB of disk than to conduct an extremely detailed analysis!
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