non-existing rollback of TRUNCATE PARTITION, causing hang due to errors.

[mjonss]

Bug Report

Please answer these questions before submitting your issue. Thanks!

During state Write Only, TRUNCATE PARTITION should be able to rollback, but currently that is not implemented until #56029 was merged, including a lot of tests. This needs to be fixed in 8.5 as well.

It also blocks insert during some states, see #55819

1. Minimal reproduce step (Required)

Remove the actual code change from #56029 and run TestTiFlashFailTruncatePartition or TestTruncatePartitionListFailuresWithGlobalIndex to see they will never complete, due to missing rollback of TRUNCATE PARTITION. patch like this: truncate_partition.patch

2. What did you expect to see? (Required)

Tests to terminate, preferably with success

3. What did you see instead (Required)

Test entered infinit loop.

From TestTiFlashFailTruncatePartition:

[2024/11/26 10:50:46.591 +01:00] [INFO] [job_worker.go:784] ["run DDL job"] [category=ddl] [jobID=118] [conn=6] [job="ID:118, Type:truncate partition, State:running, SchemaState:write only, SchemaID:2, TableID:110, RowCount:0, ArgLen:0, start time: 2024-11-26 10:34:41.456 +0100 CET, Err:[ddl:-1]enforced error, ErrCount:2643397, SnapshotVersion:0, Version: v2"]

From TestTruncatePartitionListFailuresWithGlobalIndex:

[2024/11/26 11:00:53.203 +01:00] [INFO] [job_worker.go:784] ["run DDL job"] [category=ddl] [jobID=117] [conn=3] [job="ID:117, Type:truncate partition, State:running, SchemaState:write only, SchemaID:2, TableID:110, RowCount:0, ArgLen:0, start time: 2024-11-26 11:00:10.181 +0100 CET, Err:[ddl:-1]Injected error by truncatePartFail1, ErrCount:32766215, SnapshotVersion:0, Version: v2"]

Where you see the ErrCount > 30M errors, without breaking or rolling back, in write only state, where it should be rollbackable

4. What is your TiDB version? (Required)

[mjonss]

Closed by #57724