Remove unused metric

For rediscluster we can't easily calculate the size of the pool since
counting the number of items in the queue doesn't work (the queue is
always full, just full of Nones if the queue is "empty").

We just decide to ignore that metric for now and just report the ones
that are easily available to us.

Author: Fran Garcia

baseplate/clients/redis_cluster.py

@@ -137,12 +137,9 @@ def report_runtime_metrics(self, batch: metrics.Client) -> None:
 
         size = self.connection_pool.max_connections
         open_connections = len(self.connection_pool._connections)
-        available = self.connection_pool.pool.qsize()
-        in_use = size - available
 
         batch.gauge("pool.size").replace(size)
-        batch.gauge("pool.in_use").replace(in_use)
-        batch.gauge("pool.open_and_available").replace(open_connections - in_use)
+        batch.gauge("pool.open_connections").replace(open_connections)
 
     def make_object_for_context(self, name: str, span: Span) -> "MonitoredClusterRedisConnection":
         return MonitoredClusterRedisConnection(name, span, self.connection_pool)