Monitoring and alerting tool for sebak

[Charleslee522]

We need a tool for monitoring and alerting for SEBAK The monitoring all nodes list is,

• height
• n of txs in TransactionPool
• node state(consensus, sync)
• node time

The alerting list is,

• Next block is not stacked for more than n seconds
• n of txs in TransactionPool is bigger than n
• m nodes are not in consensus state in all n nodes
• m nodes have different height with the others
• ...
• #674 checking all addresses and balances
• fix #571 or monitoring it

[Charleslee522]

Feel free to add to the list :)

[anarcher]

#548

Prometheus has their own alerting system with metric based. (https://prometheus.io/docs/practices/alerting/)