If you are creating a new function, see the Console Quickstart on Cloud Run. The content on this page only applies to existing legacy functions created with the Cloud Functions v1 API.

Report runtime function errors (1st gen)

You should handle and report runtime errors that occur in Cloud Run functions. Uncaught exceptions or executions that crash the process can result in cold starts , which you should generally try to minimize.

The recommended way for a function to signal an error depends on the function type:

HTTP functions should return appropriate HTTP status codes which denote an error. See HTTP Functions for more information.
Event-driven functions should log and return an error message. See Write event-driven functions for more information.

If errors are appropriately handled, then function instances that encounter errors can remain active and available to serve requests.

Emit errors to Error Reporting

You can emit an error from a Cloud Run function to Error Reporting as shown in the following:

Node.js

  // These WILL be reported to Error Reporting 
 throw 
  
 new 
  
 Error 
 ( 
 'I failed you' 
 ); 
  
 // Will cause a cold start if not caught

Python

  @functions_framework 
 . 
 http 
 def 
  
 hello_error_1 
 ( 
 request 
 ): 
 # This WILL be reported to Error Reporting, 
 # and WILL NOT show up in logs or 
 # terminate the function. 
 from 
  
 google.cloud 
  
 import 
 error_reporting 
 client 
 = 
 error_reporting 
 . 
  Client 
 
 () 
 try 
 : 
 raise 
 RuntimeError 
 ( 
 "I failed you" 
 ) 
 except 
 RuntimeError 
 : 
  client 
 
 . 
  report_exception 
 
 () 
 # This WILL be reported to Error Reporting, 
 # and WILL terminate the function 
 raise 
 RuntimeError 
 ( 
 "I failed you" 
 ) 
 @functions_framework 
 . 
 http 
 def 
  
 hello_error_2 
 ( 
 request 
 ): 
 # These errors WILL NOT be reported to Error 
 # Reporting, but will show up in logs. 
 import 
  
 logging 
 import 
  
 sys 
 print 
 ( 
 RuntimeError 
 ( 
 "I failed you (print to stdout)" 
 )) 
 logging 
 . 
 warning 
 ( 
 RuntimeError 
 ( 
 "I failed you (logging.warning)" 
 )) 
 logging 
 . 
 error 
 ( 
 RuntimeError 
 ( 
 "I failed you (logging.error)" 
 )) 
 sys 
 . 
 stderr 
 . 
 write 
 ( 
 "I failed you (sys.stderr.write) 
 \n 
 " 
 ) 
 # This is considered a successful execution and WILL NOT be reported 
 # to Error Reporting, but the status code (500) WILL be logged. 
 from 
  
 flask 
  
 import 
 abort 
 return 
 abort 
 ( 
 500 
 )

Go

  package 
  
 tips 
 import 
  
 ( 
  
 "fmt" 
  
 "net/http" 
  
 "os" 
  
 "github.com/GoogleCloudPlatform/functions-framework-go/functions" 
 ) 
 func 
  
 init 
 () 
  
 { 
  
 functions 
 . 
 HTTP 
 ( 
 "HTTPError" 
 , 
  
 HTTPError 
 ) 
 } 
 // HTTPError describes how errors are handled in an HTTP function. 
 func 
  
 HTTPError 
 ( 
 w 
  
 http 
 . 
 ResponseWriter 
 , 
  
 r 
  
 * 
 http 
 . 
 Request 
 ) 
  
 { 
  
 // An error response code is NOT reported to Error Reporting. 
  
 // http.Error(w, "An error occurred", http.StatusInternalServerError) 
  
 // Printing to stdout and stderr is NOT reported to Error Reporting. 
  
 fmt 
 . 
 Println 
 ( 
 "An error occurred (stdout)" 
 ) 
  
 fmt 
 . 
 Fprintln 
 ( 
 os 
 . 
 Stderr 
 , 
  
 "An error occurred (stderr)" 
 ) 
  
 // Calling log.Fatal sets a non-zero exit code and is NOT reported to Error 
  
 // Reporting. 
  
 // log.Fatal("An error occurred (log.Fatal)") 
  
 // Panics are reported to Error Reporting. 
  
 panic 
 ( 
 "An error occurred (panic)" 
 ) 
 }

Java

  import 
  
 com.google.cloud.functions.HttpFunction 
 ; 
 import 
  
 com.google.cloud.functions.HttpRequest 
 ; 
 import 
  
 com.google.cloud.functions.HttpResponse 
 ; 
 import 
  
 java.io.IOException 
 ; 
 import 
  
 java.util.logging.Logger 
 ; 
 public 
  
 class 
 HelloError 
  
 implements 
  
 HttpFunction 
  
 { 
  
 private 
  
 static 
  
 final 
  
 Logger 
  
 logger 
  
 = 
  
 Logger 
 . 
 getLogger 
 ( 
 HelloError 
 . 
 class 
 . 
 getName 
 ()); 
  
 @Override 
  
 public 
  
 void 
  
 service 
 ( 
 HttpRequest 
  
 request 
 , 
  
 HttpResponse 
  
 response 
 ) 
  
 throws 
  
 IOException 
  
 { 
  
 // These will NOT be reported to Error Reporting 
  
 System 
 . 
 err 
 . 
 println 
 ( 
 "I failed you" 
 ); 
  
 logger 
 . 
 severe 
 ( 
 "I failed you" 
 ); 
  
 // This WILL be reported to Error Reporting 
  
 throw 
  
 new 
  
 RuntimeException 
 ( 
 "I failed you" 
 ); 
  
 } 
 }

If you would like more fine-grained error reporting, you can use the Error Reporting client libraries .

You can view the reported errors in Error Reporting in the Google Cloud console. You can also see the errors reported from a particular function when you select it from the list of functions in the Google Cloud console.

Uncaught exceptions produced by your function will appear in Error Reporting. Note that some types of uncaught exceptions (such as those thrown asynchronously) will cause a cold start to occur upon a future function invocation. This increases the amount of time your function will take to run.