Simplify trace span id generation (vercel#32946)

Uses a simple counter for span ids, previously these required to be randomly generated but I've changed the importer script to ensure it gets prepended `0`s to make sure it gets to 16 characters which Jaeger requires.



## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `yarn lint`

Author: timneutkens

packages/next/trace/report/to-json.ts

@@ -12,9 +12,9 @@ const localEndpoint = {
 
 type Event = {
   traceId: string
-  parentId?: string
+  parentId?: number
   name: string
-  id: string
+  id: number
   timestamp: number
   duration: number
   localEndpoint?: typeof localEndpoint
@@ -119,8 +119,8 @@ const reportToLocalHost = (
   name: string,
   duration: number,
   timestamp: number,
-  id: string,
-  parentId?: string,
+  id: number,
+  parentId?: number,
   attrs?: Object
 ) => {
   const distDir = traceGlobals.get('distDir')

packages/next/trace/shared.ts

@@ -1,6 +1,4 @@
-// eslint typescript has a bug with TS enums
-
-export type SpanId = string
+export type SpanId = number
 
 export const traceGlobals: Map<any, any> = new Map()
 export const setGlobal = (key: any, val: any) => {

packages/next/trace/trace.ts

@@ -1,10 +1,12 @@
-import { customAlphabet } from 'next/dist/compiled/nanoid/index.cjs'
 import { SpanId } from './shared'
 import { reporter } from './report'
 
 const NUM_OF_MICROSEC_IN_SEC = BigInt('1000')
-const nanoid = customAlphabet('0123456789abcdefghijklmnopqrstuvwxyz', 8)
-const getId = () => Buffer.from(nanoid(), 'utf8').toString('hex')
+let count = 0
+const getId = () => {
+  count++
+  return count
+}
 
 // eslint typescript has a bug with TS enums
 /* eslint-disable no-shadow */

scripts/send-trace-to-jaeger.mjs

@@ -37,6 +37,15 @@ fn send_json_to_zipkin(zipkin_api: &str, value: String) {
     println!("body = {:?}", res.text());
 }
 
+// function to append zero to a number until 16 characters
+fn pad_zeros(num: u64) -> String {
+    let mut num_str = num.to_string();
+    while num_str.len() < 16 {
+        num_str = format!("0{}", num_str);
+    }
+    num_str
+}
+
 fn main() {
     let service_name = "nextjs";
     let ipv4 = "127.0.0.1";
@@ -68,6 +77,13 @@ fn main() {
                                 logged_url = true;
                             }
                             data["localEndpoint"] = Value::Object(local_endpoint.clone());
+
+                            data["id"] = Value::String(pad_zeros(data["id"].as_u64().unwrap()));
+                            if data["parentId"] != Value::Null {
+                                data["parentId"] =
+                                    Value::String(pad_zeros(data["parentId"].as_u64().unwrap()));
+                            }
+
                             data
                         })
                         .collect::<Value>(),
@@ -79,6 +95,8 @@ fn main() {
 
                 let json_map = serde_json::to_string(&v).expect("Failed to serialize");
 
+                // println!("{:}", json_map);
+
                 send_json_to_zipkin(&zipkin_api, json_map);
             }
         }