[Bug]: 2.3 proxy is not compatible with 2.2.x querynode

[congqixia]

Is there an existing issue for this?

• [X] I have searched the existing issues

Environment

- Milvus version: 2.3.0 beta & 2.2.x
- Deployment mode(standalone or cluster): 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

Query request from proxy(2.2.x) to 2.3.0beta querynode will cause panicking

Expected Behavior

No panicking or prevent query request from 2.2.x proxy to 2.3 qn

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[congqixia]

In master branch the search plan is structured like https://github.com/milvus-io/milvus/blob/b7cb34b9667f7d22366e4ccc3d930ed1be81126d/internal/parser/planparserv2/plan_parser_v2.go#L78-L84 while 2.2.x plan is https://github.com/milvus-io/milvus/blob/5f96f4bbfd9de15fa21e8b678a7ff82cc560a378/internal/parser/planparserv2/plan_parser_v2.go#L78-L83

[longjiquan]

https://github.com/milvus-io/milvus/blob/04364129fb39d09229177672e3b41a1be85df70b/internal/core/src/query/PlanProto.cpp#L166-L175

[longjiquan]

This case won't make querynode panic, the query just got error at line:168.

[longjiquan]

/assign @congqixia

[congqixia]

Confirmed.