I think XML is better than protobufs when it comes to long-term even storage. Three very big problems with protobufs: (1) Protobufs are not self-describing. Th

I think XML is better than protobufs when it comes to long-term even storage. Three very big problems with protobufs: (1) Protobufs are not self-describing. There is a meta-model but you can't really understand the data unless you have access to the schema. This means just to be safe you might end up storing the schema beside every message or at least a reference to the schema. Welcome to the schema management business. (2) Protobufs aren't extensible. In practice this means any time a system wants to introduce a new field they have to submit a proposal to some sort of highly centralized "Architecture Group." This is followed by lots of debate. Then, if you're lucky, it gets put in and a few systems adopt it. With XML you can slice off namespaces and let people innovate in those namespaces. (3) Protobufs aren't human readable. At the end of the day this means you need special tools to do anything with them. Meanwhile XML can actually be imported directly into Excel. There's a whole ecosystem of powerful technologies around XML that make it work very well in this case. People underestimate how valuable this is because they're still not thinking of the log as its own first-class product. That said, perfect is the enemy of good. This could be a good step in the right direction and migrating to XML in the future would be pretty easy because it becomes a very simple event transformation.