1) "connection refused" - that I noticed a lot for many RIGS ( DDOS protection is too restrictive or server is overloaded ) ;
2) many orphaned blocks caused by too late coin being disabled or bad configuration when there is a chain split
I believe the root of evil is the same for both: the hardware is too weak to handle more than a certain number of miners connections -> when this limit is reached, the stratum server falls off and miners start getting "connection refused" -> when stratum server goes up and miners resume working on the block, that block comes too late and the network refuses it (i.e. it becomes "orphan").
However, it's just my theory, I don't know what actually goes there.
I hope pinpins will select a good server with this CPU: Intel
2x Xeon E5-2680v4 - 28c/56t - 2.4GHz /3.3GHz RAM: 512GB DDR4 ECC 2133 MHz with
2 x 450GB NVME SSD (
https://www.ovh.ie/dedicated_servers/enterprise/1801mg04.xml )
otherwise he will not be able to compete with zpool server that has more than 40000 miners simultaneously.
also :
Recommended installation of yiimp for large pools
Server setup break-down:
Server 1: Web Server
Server 2: DB Server
Server 3: Stratum Server
Server 4: Coin Daemon Server
I would install on the same powerful server both DB and Web Server to avoid network latency delay for each DB request.
Additional Servers can be setup to improve the network performance;
Server 5-7: Can be set as either backup web server,
high diff stratum server, secondary coin server
But the most important part is to have dual Xeon 2x Xeon E5-2680v4 - 28c/56t , because miners are like a swarm of bees, all moving simultanously from one algo to another, and using many smaller servers for different algos does not help, because most fo the time many servers will not be used, but if you have a powerful server it can handle large traffic amounts, specially for stratum to avoid "connection denied" and for web server with NGINX to handle the huge number of api requests form all miners that are downloading statistics via API.
What do you think, pinpins ?