OK I'm sure this one has been asked before too but I have not been able to find it in a search.

How many miles should I put on a chain before it needs to be replaced? I will have over 2000 miles on this chain very soon. A friend told me that a chain should be replaced at around 2000. I will be touring Italy in the fall and will have well over 2000 miles by that time. I do not want to experience problems with my chain while on tour. Should I replace it?