lightning might report "verify allocator base failed. local..." using parallel import and they have same task id

[D3Hunter]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

suppose we are using 2 instances to do parallel import, if they start at same time, their task ID will be the same as we use current time as the id, but we expect 2, it might fail when allocating row ids.

tidb/lightning/pkg/server/lightning.go

Line 359 in 7e9f853

taskCfg.TaskID = time.Now().UnixNano()

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

success

3. What did you see instead (Required)

fail

4. What is your TiDB version? (Required)

master

[D3Hunter]

start those instances one by one with some small interval can workaround this

[ei-sugimoto]

I would like to tackle this program. How about using uuid?

[D3Hunter]

I would like to tackle this program. How about using uuid?

lgtm