I noticed that Digitalocean adds these lines to /etc/sysctl.conf every time a droplet is created:
# Digital Ocean Recommended Settings:
net.ipv4.tcp_rmem= 10240 87380 12582912
net.ipv4.tcp_wmem= 10240 87380 12582912
But there's a bug which adds these lines to droplets which are created from snapshots as well, this results in multiple entries for same setting, in my case, I already tuned these settings. I think its okay to add these lines, but commented out. Furthermore, you should consider snapshots as perfectly crafted piece of backups, and try NOT to modify any file in case of snapshots.
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