As long as you respect the residency requirement to renew, you are OK. Two years in Canada out of five years at the moment of renewing your card. Also, there are some exceptions to the rule (for example, working for a Canadian company who sent you abroad counts as in Canada).
What kind of travel document do I need to apply for if I need to stay out of Canada for an extended period of time?
I have been studying and working in Canada for a long time and have become a permanent resident. For personal reasons, I have to leave Canada for at least two years. I am wondering if I need to apply for any kind of travel document before I leave. I don’t want to lose my permanent residency or have any trouble when re-entering the country.