...
- RAM - allocation of a sufficient amount of memory. It is ideal to reserve memory in a virtual environment, so that memory is not shared between virtual machines (so-called ballooning).
Small D2000 applications need roughly 1 GB of RAM (the minimum for an application server on Windows/Linux is 4-8 GB), large ones several GB to tens of GB, depending on the number of configured objects, processes, and users. If more memory is available, we recommend allocating it to the SQL database for the archive (we recommend PostgreSQL) and the archive cache (we recommend several GB for the so-called isochronous cache). Applications using EDA technology (Energy Databank) benefit from several GB of memory allocated to the EDA server. - CPU - the usage of CPU strongly depends on the nature of the application (constant CPU consumption for SCADA-type applications, significant peaks for balance systems or systems where user-triggered events take place - e.g. preparation of documents for monthly invoicing). In the case of physical servers, today's processors have enough necessary performance. In a virtualized environment, we encountered a case where VMware administrators artificially limited the maximum usable frequency for the balance system, because they thought it "consumed too much CPU". First, they caused significant user dissatisfaction (the preparation of invoicing documents took instead of 30 minutes several hours) and, on the one hand, the analysis showed that a significant part of the performance was consumed by the antivirus (ESET NOD), since it did not have configured exceptions.
For large applications, it is advisable to allocate more vCPUs (4-8-16) - the D2000 architecture allows good parallelization (parallel tasks within the D2000 Kernel, D2000 Event, and D2000 Archive processes [configurable]). - Disk space:
- for the partition with the OS, we recommend approx. 20 GB (Linux) or 100 GB (Windows)
- for the partition with D2000, we recommend at least 40 GB for the start, while the archive database usually has the largest consumption - several GB to several TB (for SELT systems, the monitoring database - up to tens of GB)
- if depository databases are enabled in the D2000 Archive (storage of historical data with unlimited depth), we recommend a separate partition for the depository databases (the size of the depository databases will gradually grow on it). Currently, there are customers with more than 20 TB depository databases, but newer versions of the D2000 allow you to turn on depository data compression, which usually has a compression ratio of 1:10 and better, which significantly saves disk space.
...