Javascript 在express/nodejs中创建和结束跟踪范围的正确方法
我正在尝试nodejs/express库,并试图重写Istio中的Javascript 在express/nodejs中创建和结束跟踪范围的正确方法,javascript,node.js,express,opentracing,open-telemetry,Javascript,Node.js,Express,Opentracing,Open Telemetry,我正在尝试nodejs/express库,并试图重写Istio中的bookinfo 我遵循下列文件中给出的跟踪程序配置: 我的请求处理程序如下所示: router.get('/:productIdStr', function(req, res, next) { starsReviewer1 = -1 starsReviewer2 = -1 var productId = parseInt(req.params.productIdStr) tracer =
bookinfo
我遵循下列文件中给出的跟踪程序配置:
我的请求处理程序如下所示:
router.get('/:productIdStr', function(req, res, next) {
starsReviewer1 = -1
starsReviewer2 = -1
var productId = parseInt(req.params.productIdStr)
tracer = req.app.locals.tracer
api.context.with(api.propagation.extract(api.ROOT_CONTEXT, req.headers),async () => {
//---
var returnedData=""
span = {}
Promise.all(
[ function(){
span = req.app.locals.tracer.startSpan('calculate-reviews', {
kind: 1, // server
attributes: { star_colour: starColor },
});
let promise;
api.context.with(api.setSpan(api.context.active(), span),async () => {
additionalHeaders = {'Content-Type':'application/json'}
function addHeader(value, index, array) {
if (typeof req.headers[value] !== 'undefined' && req.headers[value] !== null){
additionalHeaders[value] = req.headers[value]}
}
headersToPropogate.forEach(addHeader)
api.propagation.inject(api.context.active(),additionalHeaders)
requstPath='http://'+ratingsService +":"+ratingsServicePort + "/ratings/" + productId
//GetRatings
// Make HTTP Call to the ratings service here.
promise = axios.get(
requstPath,
{headers:additionalHeaders}
)
.then((res) => {
log_info(span,"Get Ratings give value")
span.addEvent('Data available from ratings ');
returnedData=res.data
})
.catch((error) => {
log_info(span,"Get Ratings did not give value, Using default Values")
span.addEvent('Data not available from ratings ');
console.error(error)
})
.finally(() => {
span.end();
});
})
return promise;
}()]
)
.then(() => {
if (returnedData !== ""){
res.writeHead(200, {'Content-type': 'application/json'})
res.end(JSON.stringify(getJsonResponse(productId,returnedData.ratings.Reviewer1, returnedData.ratings.Reviewer1)))
}
else{
res.writeHead(200, {'Content-type': 'application/json'})
res.end(JSON.stringify(getJsonResponse(productId,starsReviewer1, starsReviewer1)))
}
})
.catch((error) => {
res.writeHead(200, {'Content-type': 'application/json'})
res.end(JSON.stringify(getJsonResponse(productId,starsReviewer1, starsReviewer1)))
})
.finally(()=>{
span.end()
})
})
//---
});
我面临的问题是,当我查看生成的痕迹时,它似乎是错误的:
这些问题是:
- “计算评论”范围未关闭
- 如何删除似乎自动添加的“HTTP GET”。我试图覆盖这是我的跟踪设置,但它不起作用。相反,除了
之外,似乎还创建了一个新的httpget
node-express-reviews服务:
- HTTP调用rating.default的范围在
调用之前开始和结束。理想情况下,calculate reviews
评级的范围。默认值应在
计算审核之后开始,在计算审核之前结束。但是在图像中,
span在calcualte reviews
之后开始和结束。我做错了什么?正确的做法是什么ratings.default
- 我在“calculate reviews”下得到的错误“clock skew adjustment disabled;not Applieve calculated delta of-53.6005ms”是什么
router.get('/:productIdStr', async (req, res) => {
const starsReviewer1 = -1;
const starsReviewer2 = -1;
const productId = parseInt(req.params.productIdStr);
const tracer = req.app.locals.tracer;
await new Promise(resolve => api.context.with(api.propagation.extract(api.ROOT_CONTEXT, req.headers), resolve)); // Not sure what this does? It doesn't return anything?
const span = req.app.locals.tracer.startSpan('calculate-reviews', {
kind: 1, // server
attributes: { star_colour: starColor },
});
await new Promise(resolve => api.context.with(api.setSpan(api.context.active(), span), resolve)); // Still not sure what this does, as it still doesn't return anything
const additionalHeaders = { 'Content-Type': 'application/json' };
headersToPropogate.forEach(value => { // headersToPropogate is undefined?
if (typeof req.headers[value] !== 'undefined' && req.headers[value] !== null) {
additionalHeaders[value] = req.headers[value]
}
});
api.propagation.inject(api.context.active(), additionalHeaders); // No idea what this does, it doesn't seem to be asynchronous
const requstPath = 'http://' + ratingsService + ":" + ratingsServicePort + "/ratings/" + productId;
const returnedData = await axios.get(
requstPath,
{ headers: additionalHeaders }
).data;
if (returnedData !== "") {
res.writeHead(200, { 'Content-type': 'application/json' })
res.end(JSON.stringify(getJsonResponse(productId, returnedData.ratings.Reviewer1, returnedData.ratings.Reviewer1)))
}
else {
res.writeHead(200, { 'Content-type': 'application/json' })
res.end(JSON.stringify(getJsonResponse(productId, starsReviewer1, starsReviewer1)))
}
span.end(); // No idea what this is either
});
天哪,这段代码需要一些深层次的重构。你怎么能看出来?在函数内部有带
.then()
的承诺,在函数内部有带的承诺,在数组内部有一个自调用函数内部有回调,在承诺内部有数组。在路由处理程序内部,在定义承诺之前,也可以返回承诺(您在异步回调中定义了它,因此它将在返回后定义)什么是api.context.with
?它接受一个没有参数的回调函数?所以它什么也不返回?但仍然接受一个回调函数?我不明白。还有Promise。所有的都有一个只有一个Promise的数组,所以不需要Promise。总之,一个简单的Promise就可以了。我正在尝试重构和理解这段代码,但是没有有那么多错误和不可理解的东西。api.context.with
不返回任何东西,但仍然使用回调函数?为什么?headersToPropogate
未定义。许多变量在声明时没有常量,这使它们成为全局变量(starsReviewer1
、starsReviewer2
和requstPath
例如)。ratingsService
和ratingsServicePort
未定义。starsReviewer2
未使用,等等。嗨,Jeremy,谢谢你的帮助。你是对的,代码确实需要很多重构。。。(我也在学习如何正确使用承诺)。
router.get('/:productIdStr', async (req, res) => {
const starsReviewer1 = -1;
const starsReviewer2 = -1;
const productId = parseInt(req.params.productIdStr);
const tracer = req.app.locals.tracer;
await new Promise(resolve => api.context.with(api.propagation.extract(api.ROOT_CONTEXT, req.headers), resolve)); // Not sure what this does? It doesn't return anything?
const span = req.app.locals.tracer.startSpan('calculate-reviews', {
kind: 1, // server
attributes: { star_colour: starColor },
});
await new Promise(resolve => api.context.with(api.setSpan(api.context.active(), span), resolve)); // Still not sure what this does, as it still doesn't return anything
const additionalHeaders = { 'Content-Type': 'application/json' };
headersToPropogate.forEach(value => { // headersToPropogate is undefined?
if (typeof req.headers[value] !== 'undefined' && req.headers[value] !== null) {
additionalHeaders[value] = req.headers[value]
}
});
api.propagation.inject(api.context.active(), additionalHeaders); // No idea what this does, it doesn't seem to be asynchronous
const requstPath = 'http://' + ratingsService + ":" + ratingsServicePort + "/ratings/" + productId;
const returnedData = await axios.get(
requstPath,
{ headers: additionalHeaders }
).data;
if (returnedData !== "") {
res.writeHead(200, { 'Content-type': 'application/json' })
res.end(JSON.stringify(getJsonResponse(productId, returnedData.ratings.Reviewer1, returnedData.ratings.Reviewer1)))
}
else {
res.writeHead(200, { 'Content-type': 'application/json' })
res.end(JSON.stringify(getJsonResponse(productId, starsReviewer1, starsReviewer1)))
}
span.end(); // No idea what this is either
});