Request ID

[mstoykov]

Currently in a lot of places we write the address of the handler currently processing the request. This has downsides:

1. no easy and consistent way to trace request between different handlers
2. the address are heavily reused

because of this I propose each request to have it's own ID. that is given to it when the request is accepted in app/net.go. This id can than be put inside the context and used where ever needed.

This raises some additional questions:

• Should the id be just a (unique) number or should it be something that has meaningful information?
• Should there be size limitation on the id and if yes, what?
• If the id is just a number, should when it's created, some meaningful information to be logged about the request?
• Some handlers(mp4/flv) have to make additional new requests. It will be nice to have their own unique ids. Also it will be better if they are related to the original one.
• Should any of this be configurable

Meaningful Information is understood non exclusively to include:

• the url that is requested
• some headers(mostly the Host one)
• the time of the request
• the remote address

[mstoykov]

My proposal is:

• just a number in the app/net.go generated from a counter and some instance specific information, hashed/prefixed id of sorts.
• size limitation of around 20 characters: if the id is hexed that is 655,360,000,000,000,000,000 this is more than 2^64 which is fine, unique for until a 64bit int loops is good enough for me :)
• the id with some meaningful information is logged - the accesslog includes it as well, or just the accesslog depending on what information is logged
• the id is appended in the case of in handler sub requests(mp4/flv). And we hope that no handler chain with a bunch of those is used.

47e220fb5eb29f3ec6bedb881d2424cb
47e220fb5eb29f3ec6bedb881d2424cb->fcc8157a14195d55303ca4846bb9d379

• The server id should probably be a config option of sort. Maybe one for the size of the request id. What information is logged at request id creation could be configurable as well.

[ironsmile]

:+1: I think it would be a great idea to add it in the response headers as an X-* header. Maybe X-RID. This maybe configurable as well. In some situations we may want it, in others - not.