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Fix panic in VTOrc#10519

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GuptaManan100 merged 3 commits intovitessio:mainfrom
planetscale:vtorc-panic-fix
Jun 22, 2022
Merged

Fix panic in VTOrc#10519
GuptaManan100 merged 3 commits intovitessio:mainfrom
planetscale:vtorc-panic-fix

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@GuptaManan100 GuptaManan100 commented Jun 16, 2022 •
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Description

A panic was seen in VTOrc with the following log -

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x58 pc=0xec5205]

goroutine 1444 [running]:
vitess.io/vitess/go/vt/orchestrator/logic.electNewPrimary({_, _}, {{{0xc00134cd70, 0xc}, 0xcea}, {{0xc00134ce80, 0xc}, 0xcea}, 0x2, {0x0, ...}, ...}, ...)
	vitess.io/vitess/go/vt/orchestrator/logic/topology_recovery.go:1778 +0x485
vitess.io/vitess/go/vt/orchestrator/logic.executeCheckAndRecoverFunction({{{0xc00134cd70, 0xc}, 0xcea}, {{0xc00134ce80, 0xc}, 0xcea}, 0x2, {0x0, 0x0, 0x0}, ...}, ...)
	vitess.io/vitess/go/vt/orchestrator/logic/topology_recovery.go:1395 +0xbbe
vitess.io/vitess/go/vt/orchestrator/logic.CheckAndRecover.func1()
	vitess.io/vitess/go/vt/orchestrator/logic/topology_recovery.go:1483 +0x5f
created by vitess.io/vitess/go/vt/orchestrator/logic.CheckAndRecover
	vitess.io/vitess/go/vt/orchestrator/logic/topology_recovery.go:1482 +0x470

On investigation it was found to occur because the *events.Reparent field returned was nil and the code does not check if the field is nil.

This PR fixes this panic by checking if ev is nil before using its fields.

This PR also increases the timeout of the default values of LockShardTimeoutSeconds and WaitReplicasTimeoutSeconds to 30 seconds each.

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  • "Backport me!" label has been added if this change should be backported
  • Tests were added or are not required
  • Documentation was added or is not required

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github-actions bot commented Jun 16, 2022

Review Checklist

Hello reviewers! 👋 Please follow this checklist when reviewing this Pull Request.

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deepthi
deepthi reviewed Jun 17, 2022
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The changes look good.
I'm just wondering if it is possible to write a test for this at all.
If that is too hard, can you confirm that this was verified via manual testing?

@GuptaManan100
test: reproduce the panic as a unit test
3b9a740 
Signed-off-by: Manan Gupta <manan@planetscale.com>
@GuptaManan100
feat: check ev is not nil before using its fields
11d29c0 
Signed-off-by: Manan Gupta <manan@planetscale.com>
@GuptaManan100
feat: increase timeout of LockShard and wait replicas in VTOrc defaul…
fd8f7c6 
…t config

Signed-off-by: Manan Gupta <manan@planetscale.com>
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GuptaManan100 commented Jun 20, 2022

@deepthi Yes, when I found the problem, I jumped and fixed it without adding a reproducing test. I have fixed that now. There is a test which reproduces the panic (and fails on main), which passes after the changes!

@GuptaManan100 GuptaManan100 merged commit 82bfcbc into vitessio:main Jun 22, 2022
@GuptaManan100 GuptaManan100 deleted the vtorc-panic-fix branch June 22, 2022 01:03
GuptaManan100 added a commit to planetscale/vitess that referenced this pull request Jun 22, 2022
@GuptaManan100
Fix panic in VTOrc (vitessio#10519)
538ec19 
* test: reproduce the panic as a unit test

Signed-off-by: Manan Gupta <manan@planetscale.com>

* feat: check ev is not nil before using its fields

Signed-off-by: Manan Gupta <manan@planetscale.com>

* feat: increase timeout of LockShard and wait replicas in VTOrc default config

Signed-off-by: Manan Gupta <manan@planetscale.com>
@GuptaManan100 GuptaManan100 mentioned this pull request Jun 22, 2022
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GuptaManan100 added a commit that referenced this pull request Jun 22, 2022
@GuptaManan100
Fix panic in VTOrc (#10519) (#10564)
6ae6fe2 
* test: reproduce the panic as a unit test

Signed-off-by: Manan Gupta <manan@planetscale.com>

* feat: check ev is not nil before using its fields

Signed-off-by: Manan Gupta <manan@planetscale.com>

* feat: increase timeout of LockShard and wait replicas in VTOrc default config

Signed-off-by: Manan Gupta <manan@planetscale.com>
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@shlomi-noach shlomi-noach Awaiting requested review from shlomi-noach

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