Development Task

In current TiKV(v8.3), large transactions can block resolve-ts from advancing, because it is calculated as min(pd-tso, min(lock.ts)), which is actually a more stringent constraint than its original definition. A lock from a pipelined txn can live several hours. This will make services dependent on resolved-ts unavailable.

• RFC rfc: Resolved-ts for Large Transactions rfcs#114
• kvproto Msg BroadcastTxnStatus; modify Heartbeat for resolved-ts improvement pingcap/kvproto#1265
• client-go feat: Broadcast min_commit_ts for pipelined transactions client-go#1458
• TiKV
  • txn_status_cache txn: introduce large_txn_cache in txn_status_cache #17460
  • broadcast msg *: implement broadcast_txn_status for tikv service #17522
  • heartbeat txn: heartbeat piggyback update of min_commit_ts #17528
  • check_txn_status
• resolver *: Prevent resolved-ts from being blocked by pipelined DML transactions. #17540
• stale read
• Pipelined DML: Ensure locks flushed won't be left orphan when transaction is killed #17794