raft entry is too large, region 2, entry size 12014018

Write ut in rust client, put 10240 kv pairs in one txn, the value is random bytes and length is 10240, the key is format!("key_________________________{}", j) which j is index in 0..10240, commit the txn failed. the error message is

Error: RegionError(Error { message: "raft entry is too large, region 2, entry size 12014018", not_leader: None, region_not_found: None, key_not_in_region: None, epoch_not_match: None, server_is_busy: None, stale_command: None, store_not_match: None, raft_entry_too_large: Some(RaftEntryTooLarge { region_id: 2, entry_size: 12014018 }), max_timestamp_not_synced: None, read_index_not_ready: None, proposal_in_merging_mode: None, data_is_not_ready: None, region_not_initialized: None, disk_full: None })

I run the same ut in c-client, it works fine, I guess the reason is rust client does not split kv pairs into batches in the same region?

Start by reproducing the Rust client transaction described in the issue: write 10,240 random 10,240-byte values in one transaction and commit them. Compare the Rust client's handling of key-value pairs in one region with the working c-client behavior; done means the workload commits without a raft entry-too-large error.