Is there a service for monitoring readings from sensors?

Question

linux

Task: there are N objects, each of which has a controller, to which M sensors are connected. The controller at each facility sends readings somewhere over the Internet. On the linux controller, so you can send data in any form using any protocol.
Are there normal services in nature (ideally SaaS, of course) to receive and display this information?
- I want to have a grouping, i.e. sensor readings are not piled up, but grouped by controllers. It is also desirable to be able to combine controllers into groups.
- I would like to have graphs for readings of sensors
- We need events. Those. the sensor reading has dropped below the threshold - do something. At least highlight red.
- Data must be sent from the controller, and not vice versa (may be NAT).
- The ability to send commands from the service to the controllers ("light this light") is highly desirable
- ease of configuration, not crazy prices, and, quite ideally, loading the configuration from the server by the controllers are especially welcome.
Services and software found only for network mounting. In theory, of course, it can be used, but it is felt that it was not made for this.
Watched :
- zabbix. Cons: Terrible interface, cannot send commands to controllers, very complex and confusing configuration, no hosted solution.
- something like https://scoutapp.com/subscriptions. It seems beautiful and fits the parameters, but the prices are very inhumane ($15/month for a "host" == controller)
- saup.nag.ru - only for counters, so it doesn't suit us. Included inadequate price and vyrviglazny interface. But it gives an idea of ​​what we would like to see.
Please advise something.

Answer 1

pachube.com zabbix.com/ru/xively.com
adatum.ru/podborka-12-skriptov-dlya-postroeniya-kr...

Answer 2

My advice is don't look for third party services. Maybe for a start you will find something suitable, but then you will want to finish it according to your needs.
Write yourself. Rent a server with a direct IP. For starters, you can try cacti as a means of displaying information and SNMP as an exchange protocol.

Answer 3

Well, set up everything to put in zabbix, everything is there.