Cloudflare Developers•10mo ago

Simultaneous fetches over 6 are being dropped instead of being queued.

Hi.
I'm doing multiple Http calls to external server via fetch(). It works locally. But anything over 6 on deployed version throws error instantly. Docs say that additional fetches should be automatically queued and executed when older ones get freed up.

4 Replies

kian•10mo ago

What's the error you're getting?

KOP•10mo ago

"Response closed due to connection limit"

kian•10mo ago

How many calls are you making?

KOP•9mo ago

I've tested with 7, 10 and 30. Even with 7 it throws error. I'm still interested in having this solved I found out that the error happens when trying to resolve fetches in Promise.all() So with this code:

let promises=[];
let results=[]
for (let i =0;i<10;i++){            
    let url = new URL("https://echo.free.beeceptor.com/")
    promises.push(fetch(url, {cf:{cacheEverything: false,cacheTtl:0}}))            

        }

let promises=[];
let results=[]
for (let i =0;i<10;i++){            
    let url = new URL("https://echo.free.beeceptor.com/")
    promises.push(fetch(url, {cf:{cacheEverything: false,cacheTtl:0}}))            

        }

this won't work: await Promise.all(promises).then(results2=>{results = results2}) but this code below works

await Promise.all(
promises.map(
    async (task)=>{
        await task.then(
            async (r)=>{
            results.push(await r.json() )
            })
        })
    )    
console.log(results)

await Promise.all(
promises.map(
    async (task)=>{
        await task.then(
            async (r)=>{
            results.push(await r.json() )
            })
        })
    )    
console.log(results)

Judging by time it takes working code to resolve, it seems to be doing 6 fetches concurrently. I think it might be error in how worker parses code for queing. And promise.all seems to be omitted.

Gaming

Programming

Simultaneous fetches over 6 are being dropped instead of being queued.