You have at least one data race in your program.
https://golang.org/doc/go1.6#runtime
https://blog.golang.org/race-detector
https://golang.org/doc/articles/race_detector.html
Looking at the panic message it looks like your findSupplierOrBuyer method
is updating a map that is part of a User's Dashboard. As the parent method
is called GetDashboard it is possible that you are sharing the same
Dashboard value between mutliple goroutines.
Have a read of the links above, and start running your tests under the race
detector; go test -race.
On Tuesday, 27 June 2017 19:25:57 UTC+10, Nupur Bansal wrote:
>
> Top part says:
>
> fatal error: concurrent map writes
>
> goroutine 23673 [running]:
> runtime.throw(0x95fc7f, 0x15)
> /usr/lib/go/src/runtime/panic.go:566 +0x95 fp=0xc420482708
> sp=0xc4204826e8
> runtime.mapassign1(0x8cb4c0, 0xc4200e8e10, 0xc420482a88, 0xc420482a68)
> /usr/lib/go/src/runtime/hashmap.go:553 +0x2e1 fp=0xc4204827f0
> sp=0xc420482708
> wservce/models.findSupplierOrBuyer(0xc42038812e, 0x6, 0x0, 0x0,
> 0xc42073e270, 0xf, 0xc420388123, 0x2, 0xba9ac0, 0xc42051c800, ...)
> /home/nupur/golang/code/src/wservce/models/userDashboard.go:153 +0xc07
> fp=0xc420482e80 sp=0xc4204827f0
> wservce/models.(*UserDashboard).GetDashboardDetails(0xc4203622a0,
> 0xba9ac0, 0xc42051c800, 0xc42073e270, 0xf, 0x1, 0x125)
> /home/nupur/golang/code/src/wservce/models/userDashboard.go:75 +0x14d
> fp=0xc420483040 sp=0xc420482e80
> wservce/controllers.Request.Dashboard(0xba9ac0, 0xc42051c800,
> 0xc42073e180, 0xf, 0xc4203880f4, 0x40, 0xc4203880f0, 0x3, 0xc42073e270,
> 0xf, ...)
> /home/nupur/golang/code/src/wservce/controllers/users.go:172 +0x106c
> fp=0xc420483410 sp=0xc420483040
> wservce/controllers.(*Request).Dashboard(0xc4202b8660, 0x0, 0x0)
> <autogenerated>:5 +0x6e fp=0xc420483488 sp=0xc420483410
> runtime.call32(0xc4204d09c0, 0xc4205aa060, 0xc420588960, 0x800000018)
>
>
> On Tuesday, June 27, 2017 at 10:04:06 AM UTC+5:30, Dave Cheney wrote:
>>
>> Your stacktrace is truncated; the crucial part appears at the top of the
>> output starting with
>>
>> panic:
>>
>> or
>>
>> runtime error:
>>
>> On Tuesday, 27 June 2017 14:31:57 UTC+10, Nupur Bansal wrote:
>>>
>>> When a load test is run on my service, after about 1000-1500 requests, I
>>> get this stack trace. I am unable to resolve why it was generated.
>>> Yes, the output from the service is passed to an output channel and is
>>> read through that channel.
>>>
>>> I am doing something like this:
>>> package main
>>>
>>> import (
>>> "fmt"
>>> //"time"
>>> )
>>>
>>> func myFunc(done chan string) {
>>> // Doing something in parallel
>>> for i := 0; i < 10; i++ {
>>> fmt.Println(i)
>>> }
>>> fmt.Println("Hey! I do useless stuff!")
>>> done <- "I'm done!" // We send a message on the channel
>>> }
>>>
>>> func main() {
>>> done1 := make(chan string)
>>> done2 := make(chan string)
>>> go myFunc(done1)
>>> go myFunc2(done2)
>>> msg := <-done1
>>> msg2 := <-done2
>>> fmt.Println(msg, msg2)
>>>
>>> fmt.Println("Message received, you were indeed useless..")
>>> }
>>>
>>> func myFunc2(done chan string) {
>>> // Doing something in parallel
>>> for i := 10; i < 20; i++ {
>>> fmt.Println(i)
>>> }
>>> fmt.Println("Hey! Baby!")
>>> done <- "I'm again done!" // We send a message on the channel
>>> }
>>>
>>>
>>> On Thursday, June 22, 2017 at 8:09:33 PM UTC+5:30, Ian Lance Taylor
>>> wrote:
>>>>
>>>> On Wed, Jun 21, 2017 at 10:49 PM, <nupur....@indiamart.com> wrote:
>>>> >
>>>> > I am getting the following error when my services are being load
>>>> tested.
>>>> > I am new to goroutines and may be missing something in my
>>>> implementation.
>>>> > My service on being hit is running 2 goroutines that call an http
>>>> request.
>>>> > After both return , the response from both http requests is returned
>>>> into a
>>>> > channel.
>>>> > What could be the possible reason of the following stack trace of
>>>> error??
>>>>
>>>> What caused the stack trace? I would have expected to see something
>>>> at the start saying why it was generated, but I didn't.
>>>>
>>>> At first glance it looks like you have a deadlock somewhere. Is there
>>>> something reading from the channels?
>>>>
>>>> Ian
>>>>
>>>
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