Perkelle

I find reading the Hypixel dev blog very interesting, so I thought I'd write about our internal systems for those who are interested.

First off, I'd like to apologise for the down time to the website and the server yesterday (Saturday) due to these upgrades. So, let's get started!

Let's start with a little context: for Perkelle, we have a dedicated server from SYS with a 4790K and 32GB of RAM, which is enough to run our game servers for now. In addition to this, we have a secondary VPS from OVH (although we're looking to move that to Scaleway) which we host our lightweight backend microservices on so that they have minimal downtime. These microservices include our new Zeus system, our VPN checking system and plugins.

I also have a VPS of my own with a Threadripper 1950X elsewhere that I run Perkelle Bot on and a Gitlab runner for our instance.

Zeus is a our new microservice that is responsible for storing and distributing server info. I originally started writing in Golang for maximum performance, however, I later switch to Kotlin as I wanted to experiment with Ktor, a Kotlin HTTP framework, and also I was able to do development faster as I know Kotlin a lot better than Golang. I opensourced the original version, the code can be viewed on GitHub here: https://github.com/Dot-Rar/MasterController

Next, I wrote Ares, a client for Zeus that is able to run on BungeeCord and on Spigot servers. This adds a layer of abstraction so that our other plugins are able to easily interact with Zeus. I originally started by using KHTTP as the HTTP client library, but later switched to Fuel, and finally Apache Fluent HC. You can see an example of how the internal Ares code looks for connecting to one of the endpoints here:
 

class GamemodeTotalCount(val pl: MultiPlatformPlugin) : Endpoint() {

    override val endpoint = "/gamemode/total"

    override val requestType = RequestType.GET

    fun execute(gamemode: Gamemode, callback: Callback) {
        pl.async {
            try {
                val res = request(queryParams=*arrayOf("gamemode" to gamemode.internalName))

                if(!res.pojo.success) {
                    pl.log("GamemodeTotalCount failed with error code: ${res.pojo.error_code}; Gamemode: $gamemode")
                    pl.wait(2) {
                        execute(gamemode, callback)
                    }
                    return@async
                }

                callback(res.pojo.total!!)
            } catch(ex: Exception) {
                ex.printStackTrace()
                pl.wait(2) {
                    execute(gamemode, callback)
                }
            }
        }
    }

    data class Response(val success: Boolean, val error_code: Int?, val total: Int?)
}

This then allows me to make simple method calls to retrieve data from Zeus.

So, when a Spigot server starts, the following process takes place:
- Contacts Zeus and reports the gamemode, hostname and port of the server.
- Zeus assigns the Spigot server a UUID
- The Ares plugin sends a heartbeat to Zeus every 15 seconds

Then, every 5 seconds, all BungeeCord instances:
- Retrieve a list of servers and all data from Zeus
- Remove dead servers (not sending heartbeat) from the BungeeCord server list
- Add new servers to the BungeeCord server list

And that's pretty much it. It's quite a simple process in reality, however, it opens up a lot of options for us. Having an external microservice controller means that in the future, we are able to scale a lot easier, and also handle inter-server communication without the crude use of Redis pubsub. 

Please let me know if you're interested in me writing more of these in the future, and what you'd like to see!

Today we're overhauling our map system.
We've added 2 new maps, End and Forest.

End, built by Reconfigure, FOODLES_NOODLES and iSynced_:


Forest, built by Reconfigure and iSynced_:



We've also added a map voting system:

When the game finishes, right click your map in the lobby to vote for your favourite map.

Finally, we've also fixed a bug that you're probably sad about us fixing - TNT is no longer infinite in dispensers. It has always been a bug, as donators get auto-fill on their cannons as a perk.

We just launched our server trailed on YouTube, we'd be appreciative if you could all go and give it a like:

You've probably had your inbox flooded recently with companies updating their privacy policies. Unfortunately, due to the GDPR we have to do the same, although this isn't necessarily a bad thing. In a nutshell, here is the data that we store on you:

Website

• Your Minecraft username
• Your Minecraft UUID
• Your IP address
• Your email address

Perkelle Bot

• Your Discord ID

Minecraft Server

• Your Minecraft UUID
• Your Minecraft username
• Your IP address, past and current
• (Staff only) Your authentication password

We will be handling GDPR requests over email only, none of our other channels. You can contact us for GDPR requests only by emailing gdpr@mail.perkelle.com. Abuse will subsequently lead to your messages being reported to your mail provider. You may be asked to verify your identity before we can provide or delete information about you.

Today, we released Perkelle. We're currently running our signature TNT Wars gamemode, which you can come and play by using the IP play.perkelle.com in Minecraft. We're constantly working on improving the game, so we recommend you join our Discord server to give us recommendations and keep up with the latest news!