badger: Infinite recursion in Item.yieldItemValue ?

Hi,

I face a difficult to debug problem with badger. It happens in the following situation:

• ingest a lot of data (say 1M key-values)
• delete that data
• stop the program (properly closing the badger database)
• relaunch the program

Then it can happen that when the program reopens the badger database, go panics with a “runtime: goroutine stack exceeds 1000000000-byte limit”.

Further tries to start the program then always face a panic.

The problem might be in my code of course, but I can’t find anything strange. I disabled everything except opening the database and iterating over key values, and panic still happens.

The traces show:

goroutine 1 [running]:
runtime.makeslice(0xef4340, 0x28, 0x28, 0xc425764000, 0x0, 0x7ff73adb46c8)
        /usr/local/go/src/runtime/slice.go:46 +0xf7 fp=0xc44cd70348 sp=0xc44cd70340 pc=0x4470f7
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*blockIterator).parseKV(0xc42d3aa990, 0xf00140000, 0xffffffff)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:114 +0x4bf fp=0xc44cd70430 sp=0xc44cd70348 pc=0xc749cf
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*blockIterator).Next(0xc42d3aa990)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:154 +0x191 fp=0xc44cd70480 sp=0xc44cd70430 pc=0xc74bd1
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*blockIterator).Init(0xc42d3aa990)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:54 +0x3d fp=0xc44cd70498 sp=0xc44cd70480 pc=0xc7414d
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*blockIterator).Seek(0xc42d3aa990, 0xc42d3a4cc0, 0x2b, 0x30, 0x0)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:84 +0x153 fp=0xc44cd704e8 sp=0xc44cd70498 pc=0xc74303
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*Iterator).seekHelper(0xc42d3a2600, 0x0, 0xc42d3a4cc0, 0x2b, 0x30)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:270 +0x11f fp=0xc44cd70550 sp=0xc44cd704e8 pc=0xc7551f
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*Iterator).seekFrom(0xc42d3a2600, 0xc42d3a4cc0, 0x2b, 0x30, 0x0)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:300 +0x12f fp=0xc44cd705b8 sp=0xc44cd70550 pc=0xc756bf
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*Iterator).seek(0xc42d3a2600, 0xc42d3a4cc0, 0x2b, 0x30)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:316 +0x55 fp=0xc44cd705f0 sp=0xc44cd705b8 pc=0xc75815
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table.(*Iterator).Seek(0xc42d3a2600, 0xc42d3a4cc0, 0x2b, 0x30)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/table/iterator.go:417 +0x82 fp=0xc44cd70620 sp=0xc44cd705f0 pc=0xc75f92
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger.(*levelHandler).get(0xc4203ae8a0, 0xc42d3a4cc0, 0x2b, 0x30, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/level_handler.go:253 +0x265 fp=0xc44cd706f8 sp=0xc44cd70620 pc=0xc8acc5
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger.(*levelsController).get(0xc420393e30, 0xc42d3a4cc0, 0x2b, 0x30, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/levels.go:727 +0xf6 fp=0xc44cd70820 sp=0xc44cd706f8 pc=0xc90e76
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger.(*DB).get(0xc42040c700, 0xc42d3a4cc0, 0x2b, 0x30, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/db.go:507 +0x1fd fp=0xc44cd70940 sp=0xc44cd70820 pc=0xc818fd
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger.(*Item).yieldItemValue(0xc4204202c0, 0xc42d3a4c30, 0x2b, 0x30, 0x2, 0x0, 0xc42d392c23)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/iterator.go:169 +0x414 fp=0xc44cd70aa8 sp=0xc44cd70940 pc=0xc86f94
github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger.(*Item).yieldItemValue(0xc4204202c0, 0xc42d3a4ba0, 0x2b, 0x30, 0x2, 0x0, 0xc42d392c03)
        /home/stef/skewer-gopath/src/github.com/stephane-martin/skewer/vendor/github.com/dgraph-io/badger/iterator.go:178 +0x4d2 fp=0xc44cd70c10 sp=0xc44cd70aa8 pc=0xc87052

And so on afterward. The calls to yieldItemValue stack until explosion.