The drinking has begun as wet weather and enhanced security did not dampen the spirits of beer enthusiasts at the 184th Oktoberfest which opened in Munich on Saturday.   Six million people from all over the world are expected to visit the world's largest beer festival, which runs until October 3.   This year, visitors will be able to download an app that shows nearby tents with available space. It will also help festival goers find lost friends -- which will be useful as the largest tent fits 10,000 people.   Drinkers will face higher beer prices -- a litre of beer will cost up to 10.95 euros ($13), 25 cents higher than last year, when 6.6 million litres of beer were guzzled over the two weeks.   Oktoberfestis hoping more people will come to the festival this year after attendance in 2016 dipped in part due to concern over terror attacks.   Security has since been bolstered at the festival, with backpacks as well as large bags now being banned.   The entrances will be watched over by more than 650 security guards, up by 200 from last year, CCTV cameras have been added and a new loudspeaker system can now be used to alert visitors in three languages: German, English and Bavarian.   Germany was rocked by a number of attacks last summer. In Munich, an 18-year-old shot nine people dead at a shopping mall before turning the gun on himself.   In the southern region of Bavaria, where Munich is located, two other attacks were claimed by the Islamic State group: a failed Syrian asylum seeker blew himself up at a music festival, wounding 15, and a 17-year-old Afghan refugee injured five in an axe attack.   On December 19, 2016, the country was traumatised when a man hijacked a truck and ploughed into shoppers at a Christmas market in Berlin, killing 12 people.