Cloud endpoints - request failed http status 500

Question

After successful deploy I'm trying to call [xxxxx.appspot.com/_ah/api/*] and I get bad request error:500, It was working till 3 weeks ago, now I'm getting crazy trying to find causes. My custom APIs are not visible on Google Apis Explorer neither (I cleaned cookies too!).

This seems an actual issue, there are questions related but any solution works for me.

Here are the logs:

{
 httpRequest: {
  status:  500   
 }
 insertId:  "5a6781240009209ba6384b12"  
 labels: {
  clone_id:  ""   
 }
 logName:  "projects/millis-v1/logs/appengine.googleapis.com%2Frequest_log"  
 operation: {
  first:  true   
  id:  "5a67812400ff0660347c4c558f0001657e6d696c6c69732d76310001323031383031323374313933333336000100"   
  last:  true   
  producer:  "appengine.googleapis.com/request_id"   
 }
 protoPayload: {
  @type:  "type.googleapis.com/google.appengine.logging.v1.RequestLog"   
  appEngineRelease:  "1.9.54"   
  appId:  "e~millis-v1"   
  endTime:  "2018-01-23T18:38:28.420341Z"   
  finished:  true   
  first:  true   
  host:  "millis-v1.appspot.com"   
  httpVersion:  "HTTP/1.1"   
  ip:  "2a01:c50e:2259:4300:486b:77c:fa4a:a270"   
  latency:  "0.002497s"   
  line: [
   0: {
    logMessage:  "The request failed because the instance could not start successfully"     
    severity:  "ERROR"     
    time:  "2018-01-23T18:38:28.420254Z"     
   }
  ]
  method:  "GET"   
  pendingTime:  "0.002370834s"   
  requestId:  "5a67812400ff0660347c4c558f0001657e6d696c6c69732d76310001323031383031323374313933333336000100"   
  resource:  "/_ah/api/discovery/v1/apis/adminappendpoint/v1/rest?fields=kind%2Cname%2Cversion%2CrootUrl%2CservicePath%2Cresources%2Cparameters%2Cmethods%2CbatchPath%2Cid&pp=0"   
  startTime:  "2018-01-23T18:38:28.417844Z"   
  status:  500   
  traceId:  "7c897e18c63dc7d114cf785474b30545"   
  urlMapEntry:  "unused"   
  userAgent:  "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"   
  versionId:  "20180123t193336"   
 }
 receiveTimestamp:  "2018-01-23T18:38:28.600329615Z"  
 resource: {
  labels: {
   module_id:  "default"    
   project_id:  "millis-v1"    
   version_id:  "20180123t193336"    
   zone:  "eu5"    
  }
  type:  "gae_app"   
 }
 severity:  "ERROR"  
 timestamp:  "2018-01-23T18:38:28.417844Z"  
}

Any hero there? thank you!.

Answer 1

The clue is in that log message: "The request failed because the instance could not start successfully".

Usually this means your app is throwing an exception during the startup of the app, before it can even handle a request. As saiyr suggests, you'll need to look to the application logs for an explanation.