Minecraft Server Installer

Last night, I wrote a script to install the Spigot Minecraft server on a server (or desktop) running CentOS 6. It will install all dependencies on a fresh installation as well as creating a user to isolate the server and setup monitoring with monit, and automatically start the server. This is ideal if you wanted to setup a server from a fresh virtual machine from a VPS provider.

Note that this starts the server with the default Minecraft server settings. You will need to stop the server via the /opt/minecraft/stop.sh script and modify the settings file if you want alternate settings.

Link: minecraft-installer.sh

Updating Postfix Aliases from Horde

Last week, I setup my own mail server using Postfix, Dovecot, and Horde. The only problem I have with this setup is there’s no way to update Postfix’s aliases directly from Horde. This may not really seem like a problem, however I have several email addresses with new addresses being created all the time for email forwarding, etc., so that I can stop mail from being delivered by removing an email address from the aliases file should I somehow lose control of the original email address. To solve this problem, I wrote a script that would pull all horde identities and email aliases and use those to populate the virtual alias maps file.

Note that this only works properly if your horde login is a user on the underlying system that can receive mail, i.e., you’re somehow authenticating directly to the passwd file or indirectly through Dovecot or another server capable of authenticating with the passwd file, though this can probably be modified as well to use virtual identities if that’s what you’re using.

Anyway, here’s the script: https://gitlab.com/snippets/3341 or https://pastebin.com/fCJv217t

DNS

I setup 4 DNS servers on Monday using RamNode and BuyVM, and have been monitoring the performance of them since then. I am running PowerDNS with MySQL backends, replicated from the Atlanta node to all other nodes using MySQL master-slave replication. Additionally, the Atlanta node is running Poweradmin.

The physical node configurations are as follows:

RamNode – Atlanta
512MB RAM
2 CPU Cores – 3.3Ghz
20GB SSD

RamNode – Seattle and Netherlands
256MB RAM
1 CPU Core – 3.3Ghz
10GB SSD

BuyVM – Las Vegas
256MB RAM
2 CPU Cores – 2Ghz
30GB Disk (non-SSD)

Monitoring results from the last 24 hours on each node from another node in RamNode’s Seattle location:

RamNode – Atlanta

dns_ramnode_atlanta

RamNode – Seattle

dns_ramnode_seattle

RamNode – Netherlands

dns_ramnode_netherlands

BuyVM – Las Vegas

dns_buyvm_lasvegas

The RamNode nodes are rather consistent, short of usually small spikes every hour or so. The BuyVM response times vary widely, however; more than I was expecting. To show just how much the responses are varying, here is a 4-hour capture of the response times:

dns_buyvm_lasvegas_4hours

I haven’t looked into why the BuyVM node is performing worse than the RamNode nodes, however I suspect it has something to do with the fact that it has a lower clock speed and its disks are non-SSDs versus the RamNode SSDs.

Update: I moved the BuyVM DNS node to DotVPS’s UK location, and it is performing much better than the BuyVM node. Here is the configuration for that node:

DotVPS – UK
512MB RAM
1 CPU Core – 2.27Ghz
25GB Disk (non-SSD)

And the performance graph for that node:

DotVPS – UK

dns_dotvps_uk

So I’m still not sure what the issue is with BuyVM. It still very sporadic up until I turned off that node. Maybe their upgrade to SSDs will fix them, however I’m not sticking around to find out.

Update: DotVPS is no longer in business and therefore links have been removed.