Revert "Merge pull request #3066 from matrix-org/rav/remove_redundant_metrics"

We aren't ready to release this yet, so I'm reverting it for now.

This reverts commit d1679a4ed7, reversing
changes made to e089100c62.

synapse/util/metrics.py

@@ -31,28 +31,53 @@ metrics = synapse.metrics.get_metrics_for(__name__)
 block_counter = metrics.register_counter(
     "block_count",
     labels=["block_name"],
+    alternative_names=(
+        # the following are all deprecated aliases for the same metric
+        metrics.name_prefix + x for x in (
+            "_block_timer:count",
+            "_block_ru_utime:count",
+            "_block_ru_stime:count",
+            "_block_db_txn_count:count",
+            "_block_db_txn_duration:count",
+        )
+    )
 )
 
 block_timer = metrics.register_counter(
     "block_time_seconds",
     labels=["block_name"],
+    alternative_names=(
+        metrics.name_prefix + "_block_timer:total",
+    ),
 )
 
 block_ru_utime = metrics.register_counter(
     "block_ru_utime_seconds", labels=["block_name"],
+    alternative_names=(
+        metrics.name_prefix + "_block_ru_utime:total",
+    ),
 )
 
 block_ru_stime = metrics.register_counter(
     "block_ru_stime_seconds", labels=["block_name"],
+    alternative_names=(
+        metrics.name_prefix + "_block_ru_stime:total",
+    ),
 )
 
 block_db_txn_count = metrics.register_counter(
     "block_db_txn_count", labels=["block_name"],
+    alternative_names=(
+        metrics.name_prefix + "_block_db_txn_count:total",
+    ),
 )
 
 # seconds spent waiting for db txns, excluding scheduling time, in this block
 block_db_txn_duration = metrics.register_counter(
     "block_db_txn_duration_seconds", labels=["block_name"],
+    alternative_names=(
+        metrics.name_prefix + "_block_db_txn_duration:total",
+    ),
 )
 
 # seconds spent waiting for a db connection, in this block