[Bug]: wrong operate to drop collection/database etc. with prefix in snapshot

[smellthemoon]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version:
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

DropDatabase has already passed the dbID, remove with prefix in snapshot may remove another db which has the same prefix. In the case that it is not easy to have the same prefix (such as collectionID), load will also have better performance.

Expected Behavior

No response

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[smellthemoon]

/assign

[yanliang567]

/unassign

[xiaofan-luan]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version:
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

DropDatabase has already passed the dbID, remove with prefix in snapshot may remove another db which has the same prefix. In the case that it is not easy to have the same prefix (such as collectionID), load will also have better performance.

Expected Behavior

No response

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

is there a spliter for the key?
for example, we can remove db/ instead db.
if we concat the key with some delimiter, this is the fast way to fix

[smellthemoon]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version:
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

DropDatabase has already passed the dbID, remove with prefix in snapshot may remove another db which has the same prefix. In the case that it is not easy to have the same prefix (such as collectionID), load will also have better performance.

Expected Behavior

No response

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

is there a spliter for the key? for example, we can remove db/ instead db. if we concat the key with some delimiter, this is the fast way to fix

But in fact, the key removed here is the key itself, not the prefix of the key. For example, when creating database, the key root-coord/database/db-info/dbid will be saved. When dropping database, pass in root-coord/database/db-info/dbid as the prefix. If has the same prefixes, will cause other db to be removed too.
multiSaveAndRmove seems more appropriate.

[xiaofan-luan]

can you give an example?

[xiaofan-luan]

don't quite understand about this part

[smellthemoon]

don't quite understand about this part

For example, you create 11 databases. The id of databases is 0-10. RootCoord will save the key "root-coord/database/db-info/dbID" in snapshot.
if you want to drop database(id =1), RootCoord will remove it by writing tombstone. the prefix here is "root-coord/database/db-info/1". snapshot will list all the keys with the prefix, and then save it. So in this case, dbID 10 will be listed for having the same prefix and will be written tombstone.

[xiaofan-luan]

the easiest fix is to always drop root-coord/database/db-info/1/ ?

[smellthemoon]

the easiest fix is to always drop root-coord/database/db-info/1/ ?

The keys now do not contain delimiters at the end, may bring some compatibility issues.

[xiaofan-luan]

so we just want to delete 1 key?

[smellthemoon]

so we just want to delete 1 key?

yes, from the code, it actually just want to delete 1 key, I have added the MultiSaveAndRemove in the snapshot interface.