client/resource_group: gate paging metrics by IsCop signal#1
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After PredictedReadBytes was promoted to a required RequestInfo method, the paging_nonprecharge_* branch fired for every non-write RPC reaching the resource-control interceptor: point gets, batch gets, scans, and internal lookups all looked identical to a paging coprocessor request whose hint happened to be zero. The "paging cold-start" counter inflated by roughly the full read-RPC volume of the cluster, breaking the precharge-vs-nonprecharge comparison panel in the TiDB dashboard. Expose IsCop() on the RequestInfo interface so the nonprecharge branch can scope itself to coprocessor requests. The hint-present branch is unchanged because hint>0 already implies a coprocessor caller; only the zero-hint branch needs the explicit cmd-type signal, which client-go's implementation will derive from tikvrpc.Request.Type. Signed-off-by: Yuhao Zhang <yhzhang00@outlook.com>
This was referenced May 18, 2026
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Summary
Addresses @rleungx's review comment on tikv#10611 (and @JmPotato's earlier #3121995964): after `PredictedReadBytes` was promoted to a required `RequestInfo` method, the `paging_nonprecharge_*` branch could no longer tell a paging cold-start RPC from a regular non-cop read (CmdGet, CmdBatchGet, CmdScan, internal lookups). All reads with a zero hint were getting counted, inflating the metric by roughly the cluster's whole read-RPC volume and breaking the precharge-vs-nonprecharge comparison panel on the TiDB dashboard.
Adds `IsCop()` to the `RequestInfo` interface so the nonprecharge branch can scope itself to coprocessor reads. The hint-present branch is unchanged because `hint > 0` already implies a coprocessor caller; only the zero-hint branch needs the explicit cmd-type signal.
Changes
Coordination
Companion changes:
Validation