Warriors head coach Sean Lineen said of 31-times capped Dougie: "I think Dougie is a quality player. He is a real perfectionist and that rubs off on the rest of the team.
"He tackles well and has so much experience. At this stage of his career, to sign again for Glasgow, just shows you what we're about."
Dougie replied: "We have the players and the desire at Glasgow to win the Magners League and it's something that I want to achieve in my time here.
"Not only do I feel we have the ability to achieve success this season, but with the other players that have committed to the club, I feel we can continue to achieve in the years to come."
On Calum Forrester, Sean continued: "Calum is young, he's hungry and there's an edge to his game.
"He is one of the unsung heroes of this Glasgow squad because he's in there behind the Killer B's (Kelly Brown, John Barclay and Johnnie Beattie). When he gets a good run of games, he can be something special, but unfortunately he's had a few injuries over the last couple of years.
"Calum's also really important to the spirit of the team because you can see that he wants to do well for Glasgow. I'm really excited with the back-row talent we've got."