The Dürkheimer Wurstmarkt is held in the town of Bad Durkheim, on the German Wine Road. Dates this year are 6-10, 13-16 September. This is a major event, with tourists from all over. Not as large as Munich Octoberfest, but bigger than most major cities main festivals.
Bad Durkheim is a very attractive town on it's own, and worth visiting. But if you're anywhere near during the dates in September you should plan to visit. Parking can be an issue, and nothing is open before 1100, but weekends get busy around mid-day and weekdays after 1600.
The local "schorle" is a half liter of wine mixed with mineral water, and this is very popular. Wine is also sold by the normal glass, carafe, or bottle by dozens of vintners, each with their own tents.
https://www.bad-duerkheim.de/kultur-tourismus/veranstaltungen-feste/duerkheimer-wurstmarkt/