We are using emonCMS up to now to collect data. We are getting bigger, with 50 IotaWatt working soon. We have read the documentation (Uploading to Servers — IoTaWatt 02_03_20 documentation), but what is the DB you would advise for us? We are considering InfluxDB as it looks popular among IoTaWatt users.
Our requirements are:
High data amount (50 IotaWatt now, hundreds in a near future)
If possible we would like to host it (but open to use cloud services as well)
Both Emoncms and influxDB are fully capable of satisfying the basic requirements that you list above.
Other consideration that could differentiate might be:
Ability to segregate data by users or groups.
Ability to use a query language to extract data.
Resources required to host.
Resources required to administrate at scale.
Cost of needed hosting platform or managed cloud service.
Backup capabilities.
Speed and capacity at present and projected scale.
These are things that I’m sure you will consider. Emoncms cloud is billed per feed. I have been uploading to influxCloud for the past month and run up a tab of about $1.20 US for 18 measurements at 10 second intervals. That very loosely translates to about $1 per measurement per year. Emoncms is $1.40 for roughly the same.
When I do the math and consider the real costs of hosting and administration, cloud services start to look good to me. At your scale, I think both options are probably negotiable.
One other consideration is long term viability of the chosen platform.
I think both options will be available for a long time. Both are open source, so you can host yourself, or pay someone to do it for you.
I use both for different things. I have been using OEM for a decade or more. I started when they were free and moved a bunch of stuff over to them when SmartEnergyGroups (from Australia) started charging. I probably would have stayed at SEG, if they had had reasonable pricing and easy billing. But, that was not the case. OEM started charging €1/feed/year with easy billing (but credits, which are deducted by usage). I think I still have about 50 active feeds. I really should get rid of some more of them, since I don’t really use some of them. They have historical data and are inexpensive enough that I have been lazy.
The better question to ask is which one provides the information you and your customers need in the easiest to understand way. InfluxDB integrates well with Grafana, which makes it possible to create some beautiful charts/interfaces. It might be possible to do that with OEM, but I don’t believe it is built in.
Of course, with that great capability comes the responsibility of creating the interface. I like InfluxDB/Grafana because I can aggregate the data from multiple IotaWatt units.