Expanding a bit on the title, I ride a 27.5" KTM Peak XT with a 3x10 setup. The chain I'm currently using is of unknown provenience (it was already there when I bought the bike, and it wasn't new). It's been almost one full year with me, probably around 6-7 months with the previous owner and it was never changed.
The chain broke once, but I replaced the broken link with a quick release link and it worked well from that point on. I'm always carrying a QR link with me since that day, in case bad things happen while on track.
Having this said, I am wondering whether or not I should replace my chain ASAP or it's just a normal thing for chains to be reliable for this long.
Also, how often should this (change the chain) happen?