I’m looking into the limits of your system : I would like to store a lot of values (a lot being around 10 000 points/sec) and I’m starting to hit a wall way lower. What I’m trying to figure out is what is causing this wall hitting. Here are a few words about my config (which I can easily provide as sqlite .db file if you wish).
OpenHistorian version : 2.7.265
Input made by Modbus. To make it more readable and to ensure a proper sampling interval, I chose to read 120 registers per blocks, read a block every second (750ms polling rate, 250ms intersequence). If there is only 1 sequence, is the total read time 1s or 750ms ? I assumed it would based on an another discussion (Maximum number of registers per second), but I’m unsure.
Also : is it ‘easier’ for the historian server to have 2 sequences (500ms polling rate, 2*250ms intersequence), or even more, rather than having multiple devices with only one sequence ?
Type of database : I chose to use a Sqlite configuration database because of its lightweightness and because I’m more familiar with it. Could it be linked to a lower efficiency ? I wouldn’t see why as the number of access on this db is rather low.
Configuration of the devices : to simplify the configuration, I have developped a very small code to add devices/measurement to a .db file. Basically I do a clean install of OpenHistorian and I then add all my devices and measurements to the configuration database and simply restart the service. Everything seems to be working fine when I add 1 to 1000 measurements, but when I start going for 5000, I can’t access anything anymore, although I don’t really understand why : the CPU on my machine seems to be OK, the read and write rates are tolerable, but the web manager can’t reach the login screen, and the ‘normal’ manager doesn’t display any data. Even stopping the service takes at least 1min.
I’ve tried with 1000 points, 2000, 3000, 4000 : it seems that up to 2000 it seems perfect, over I can’t even be sure that it’s logging any data at all.
Can you help me troubleshoot this issue ?
Thanks in advance,