[Feature] Select specific node by parameters when proxy

[zghong]

Is your feature request related to a problem? Please describe. No.

Describe the solution you'd like For a ClickHouse cluster with 2 shards and 2 replicas, the chproxy configuration could be as follows:

replicas:
  - name: "replica1"
    nodes: ["127.0.1.1:8123", "127.0.1.2:8123"]
  - name: "replica2"
    nodes: ["127.0.2.1:8123", "127.0.2.2:8123"]

By default, chproxy will select a node from these 4 nodes based on load balancing for proxy. However, sometimes I want to specify some node(s) to execute query, for example:

• Scenario 1: Data (already divided according to the sharding_key of the distributed table) needs to be written into the local table of a specific shard (e.g., the 2nd shard), because it is more efficient.
• Scenario 2: Query logs or execute maintenance commands on a specific node (e.g., node 127.0.1.2:8123).

In these cases, can we control chproxy's node selection strategy with parameters like /?replica=2 and /?replica=1&node=2?

Describe alternatives you've considered By the way, why use keywords replica and node instead of shard and replica? Perhaps this naming would make the cluster topology clearer, for example:

shards:
  - name: "shard1"
    replicas: ["127.0.1.1:8123", "127.0.1.2:8123"]
  - name: "shard2"
    replicas: ["127.0.2.1:8123", "127.0.2.2:8123"]

So, we can select the specific node with parameters like /?shard=2 and /?shard=1&replica=2. If the feature is developed, which naming is better? Or is it possible to modify the configuration specification?

Additional context No.