# Panic on tablet move v21.12.0

**URL:** <https://discuss.dgraph.io/t/panic-on-tablet-move-v21-12-0/16373>\
**Category:** Dgraph\
**Tags:** kind:bug\
**Created:** [December 20, 2021, 5:33pm UTC](https://discuss.dgraph.io/t/panic-on-tablet-move-v21-12-0/16373 "2021-12-20T17:33:12Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![iluminae](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/iluminae/32/7367_2.png) [@iluminae](https://discuss.dgraph.io/u/iluminae)\
**Post date:** [December 20, 2021, 5:33pm UTC](https://discuss.dgraph.io/t/panic-on-tablet-move-v21-12-0/16373/1 "2021-12-20T17:33:12Z")

</div>

## Report a Dgraph Bug

### What version of Dgraph are you using?

> **Dgraph Version**
>
> ```auto
> $ dgraph version
>  
> Dgraph version : v21.12.0
> Dgraph codename : zion
> Dgraph SHA-256 : 078c75df9fa1057447c8c8afc10ea57cb0a29dfb22f9e61d8c334882b4b4eb37
> Commit SHA-1 : d62ed5f15
> Commit timestamp : 2021-12-02 21:20:09 +0530
> Branch : HEAD
> Go version : go1.17.3
> jemalloc enabled : true
> 
> ```

### Have you tried reproducing the issue with the latest release?

yes

### What is the hardware spec (RAM, OS)?

k8s 16c 64GiB ram on GKE

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

Use tablet move with large tablet, ~40GiB while ingestion is going.

I did a test tablet move of a smaller tablet that took ~9m to do and wanted to do a bigger tablet move too. Mutations were happening at the time.

### Expected behaviour and actual result.

the target group of the move is now completely messed up, and is crash looping with the following panic:

```auto
I1220 17:13:42.463401 1 schema.go:496] Setting schema for attr 0-XXXXXXXXX: int, tokenizer: [], directive: NONE, count: false

2021/12/20 17:13:42 Unable to find txn with start ts: 1419795
github.com/dgraph-io/dgraph/x.AssertTruef
        /ext-go/1/src/github.com/dgraph-io/dgraph/x/error.go:107
github.com/dgraph-io/dgraph/worker.(*node).applyMutations
        /ext-go/1/src/github.com/dgraph-io/dgraph/worker/draft.go:707
github.com/dgraph-io/dgraph/worker.(*node).applyCommitted
        /ext-go/1/src/github.com/dgraph-io/dgraph/worker/draft.go:744
github.com/dgraph-io/dgraph/worker.(*node).processApplyCh.func1
        /ext-go/1/src/github.com/dgraph-io/dgraph/worker/draft.go:931
github.com/dgraph-io/dgraph/worker.(*node).processApplyCh
        /ext-go/1/src/github.com/dgraph-io/dgraph/worker/draft.go:1020
runtime.goexit
        /usr/local/go/src/runtime/asm_amd64.s:1581

```

Which comes during setting the schema for the new tablet - it is looking for a transaction number that does not exist in the `pendingTransactions` map. So - maybe it was removed from the map for some reason? The tablet move had been running for 20m but was not nearly complete. Here was the last `Sending predicate` log message from the source group:

```auto
Sending predicate: [0-XXXXXXXXX] [19m44s] Scan (8): ~10.0 GiB/39 GiB at 11 MiB/sec. Sent: 10.0 GiB at 12 MiB/sec

```

Maybe the process that periodically aborts old transactions got the predicate move/schema for that move transaction and killed the whole group as a result.

---

<div class="post-metadata">

**Author:** ![alexeevaa](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/alexeevaa/32/8341_2.png) [@alexeevaa](https://discuss.dgraph.io/u/alexeevaa)\
**Post date:** [November 18, 2022, 8:19pm UTC](https://discuss.dgraph.io/t/panic-on-tablet-move-v21-12-0/16373/2 "2022-11-18T20:19:50Z")

</div>

Were you able to restore node after this error?