Having logs is good. But just like a lot of information on Internet, it is not really useful if you don't know which link has the right information for you. It has become easier because of search engines telling us which pages have more relevant content. Similarly, logs of live applications, especially when there is a log of many services together, will not be that helpful. There will be a lot of logs. So, in order to make them usable, you should store your logs in way in which they can be searched for and be easily understood when you see them.