dgraph server got: "unexpected meta: 0"

[rhinoxi]

• What version of Dgraph are you using?
  v1.0.3 (docker)

• Have you tried reproducing the issue with latest release?
  Yes

• What is the hardware spec (RAM, OS)?
  OS: Fedora release 26
  RAM: 8G

• Steps to reproduce the issue (command/config used to run Dgraph).

  1. load the 1 million movie data
  2. query in dgraph ratel:

  {
    f(func: allofterms(name@., "New")) {
      name@.
    }
  }
  

• Expected behaviour and actual result.
  The docker container of dgraph server crashed.
  log:

  2018/02/08 09:35:46 unexpected meta: 0              
  github.com/dgraph-io/dgraph/x.Fatalf                
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/x/error.go:103                               
  github.com/dgraph-io/dgraph/posting.ReadPostingList 
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/posting/mvcc.go:427                          
  github.com/dgraph-io/dgraph/posting.getNew          
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/posting/mvcc.go:467                          
  github.com/dgraph-io/dgraph/posting.Get             
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/posting/lists.go:253                         
  github.com/dgraph-io/dgraph/worker.handleUidPostings                                                     
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:509                           
  github.com/dgraph-io/dgraph/worker.helpProcessTask  
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:678                           
  github.com/dgraph-io/dgraph/worker.processTask      
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:622                           
  github.com/dgraph-io/dgraph/worker.ProcessTaskOverNetwork                                                
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:149                           
  github.com/dgraph-io/dgraph/query.ProcessGraph      
      /home/travis/gopath/src/github.com/dgraph-io/dgraph/query/query.go:1894                          
  runtime.goexit                                      
      /home/travis/.gimme/versions/go1.9.2.linux.amd64/src/runtime/asm_amd64.s:2337
  

  As I search for another name, the server works well, like

  {
    f(func: allofterms(name@., "The Wolf of Wall Street")) {
      name@.
    }
  }
  

[rhinoxi]

Sorry, I forgot to mention I altered the schema after loading data, as the tutorial guided:

director.film: uid @reverse @count .
genre: uid @reverse .
initial_release_date: dateTime @index(year) .
name: string @index(term) .
starring: uid @count .

[rhinoxi]

I tried to remove all data with:

{"drop_all": true}

and load the data again.
When I tried to alter the schema, the server crashed with:

2018/02/08 10:21:02 unexpected meta: 0              
github.com/dgraph-io/dgraph/x.Fatalf                
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/x/error.go:103                               
github.com/dgraph-io/dgraph/posting.ReadPostingList 
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/posting/mvcc.go:427                          
github.com/dgraph-io/dgraph/posting.RebuildIndex    
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/posting/index.go:895                         
github.com/dgraph-io/dgraph/worker.(*node).rebuildOrDelIndex                                             
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/index.go:38                           
github.com/dgraph-io/dgraph/worker.runSchemaMutationHelper                                               
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/mutation.go:171                       
github.com/dgraph-io/dgraph/worker.runSchemaMutation                                                     
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/mutation.go:96                        
github.com/dgraph-io/dgraph/worker.(*node).processSchemaMutations                                        
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/draft.go:293                          
github.com/dgraph-io/dgraph/worker.(*scheduler).schedule                                                 
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/scheduler.go:152                      
github.com/dgraph-io/dgraph/worker.(*node).processApplyCh                                                
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/draft.go:360                          
runtime.goexit            
        /home/travis/.gimme/versions/go1.9.2.linux.amd64/src/runtime/asm_amd64.s:2337

[rhinoxi]

Weird. As I removed the docker volumes and reload data from beginning, the fatal error didn't occur.

[sboorlagadda]

@bellanchor are you using docker compose? or docker commands? Whats your topology?

[pawanrawal]

This was a bug in v1.0.0 and v1.0.1 and was fixed in v1.0.2. I suppose you were using data from a version before v1.0.2 and that is why you encountered it. It should not occur for data which is freshly loaded in the current version.

[rhinoxi]

@sboorlagadda I am using docker-compose as the tutorial suggests.

[rhinoxi]

@pawanrawal I loaded the data from v1.0.2, and upgraded to v1.0.3 with the same data volume.

[rhinoxi]

@sboorlagadda @pawanrawal Sorry, I can't reproduce the issue now, maybe there is some data from lower version as @pawanrawal said, which I was missing. I think we should close this issue.