From 8e139046b9a8f52dccf60bd4325207f45e0190b5 Mon Sep 17 00:00:00 2001
From: Edward Oakes <ed.nmi.oakes@gmail.com>
Date: Sun, 7 Mar 2021 20:06:02 -0600
Subject: [PATCH] [metrics] Remove unused unit field from cython classes
 (#14497)

---
 python/ray/includes/metric.pxi | 26 +++++++++-----------------
 python/ray/util/metrics.py     | 10 +++-------
 2 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/python/ray/includes/metric.pxi b/python/ray/includes/metric.pxi
index ba89ba8405b5f..811870af19059 100644
--- a/python/ray/includes/metric.pxi
+++ b/python/ray/includes/metric.pxi
@@ -70,20 +70,18 @@ cdef class Gauge(Metric):
         >>> gauge = Gauge(
                 "ray.worker.metric",
                 "description",
-                "unit",
                 ["tagk1", "tagk2"]).
             value = 5
             key1= "key1"
             key2 = "key2"
             gauge.record(value, {"tagk1": key1, "tagk2": key2})
     """
-    def __init__(self, name, description, unit, tag_keys):
+    def __init__(self, name, description, tag_keys):
         """Create a gauge metric
 
         Args:
             name (string): metric name.
             description (string): description of this metric.
-            unit (string): measure unit of this metric.
             tag_keys (list): a list of tay keys in string format.
         """
         super().__init__(tag_keys)
@@ -92,7 +90,7 @@ cdef class Gauge(Metric):
             new CGauge(
                 name.encode("ascii"),
                 description.encode("ascii"),
-                unit.encode("ascii"),
+                b"",  # Unit, unused.
                 self.c_tag_keys
             )
         )
@@ -106,7 +104,6 @@ cdef class Count(Metric):
         >>> count = Count(
                 "ray.worker.metric",
                 "description",
-                "unit",
                 ["tagk1", "tagk2"]).
             value = 5
             key1= "key1"
@@ -116,13 +113,12 @@ cdef class Count(Metric):
 
        Count: The count of the number of metric points.
     """
-    def __init__(self, name, description, unit, tag_keys):
+    def __init__(self, name, description, tag_keys):
         """Create a count metric
 
         Args:
             name (string): metric name.
             description (string): description of this metric.
-            unit (string): measure unit of this metric.
             tag_keys (list): a list of tay keys in string format.
         """
         super().__init__(tag_keys)
@@ -131,7 +127,7 @@ cdef class Count(Metric):
             new CCount(
                 name.encode("ascii"),
                 description.encode("ascii"),
-                unit.encode("ascii"),
+                b"",  # Unit, unused.
                 self.c_tag_keys
             )
         )
@@ -145,7 +141,6 @@ cdef class Sum(Metric):
         >>> metric_sum = Sum(
                 "ray.worker.metric",
                 "description",
-                "unit",
                 ["tagk1", "tagk2"]).
             value = 5
             key1= "key1"
@@ -155,13 +150,12 @@ cdef class Sum(Metric):
 
        Sum: A sum up of the metric points.
     """
-    def __init__(self, name, description, unit, tag_keys):
+    def __init__(self, name, description, tag_keys):
         """Create a sum metric
 
         Args:
             name (string): metric name.
             description (string): description of this metric.
-            unit (string): measure unit of this metric.
             tag_keys (list): a list of tay keys in string format.
         """
 
@@ -171,7 +165,7 @@ cdef class Sum(Metric):
             new CSum(
                 name.encode("ascii"),
                 description.encode("ascii"),
-                unit.encode("ascii"),
+                b"",  # Unit, unused.
                 self.c_tag_keys
             )
         )
@@ -184,8 +178,7 @@ cdef class Histogram(Metric):
 
         >>> histogram = Histogram(
                 "ray.worker.histogram1",
-                "desciprtion",
-                "unit",
+                "description",
                 [1.0, 2.0], # boundaries.
                 ["tagk1"])
             value = 5
@@ -195,13 +188,12 @@ cdef class Histogram(Metric):
 
        Histogram: Histogram distribution of metric points.
     """
-    def __init__(self, name, description, unit, boundaries, tag_keys):
+    def __init__(self, name, description, boundaries, tag_keys):
         """Create a sum metric
 
         Args:
             name (string): metric name.
             description (string): description of this metric.
-            unit (string): measure unit of this metric.
             boundaries (list): a double type list boundaries of histogram.
             tag_keys (list): a list of tay key in string format.
         """
@@ -216,7 +208,7 @@ cdef class Histogram(Metric):
             new CHistogram(
                 name.encode("ascii"),
                 description.encode("ascii"),
-                unit.encode("ascii"),
+                b"",  # Unit, unused.
                 c_boundaries,
                 self.c_tag_keys
             )
diff --git a/python/ray/util/metrics.py b/python/ray/util/metrics.py
index 57a01cf7aa0b4..1edc9fd8ec9b6 100644
--- a/python/ray/util/metrics.py
+++ b/python/ray/util/metrics.py
@@ -27,9 +27,6 @@ def __init__(self,
                              "Please provide a metric name.")
         self._name = name
         self._description = description
-        # We don't specify unit because it won't be
-        # exported to Prometheus anyway.
-        self._unit = ""
         # The default tags key-value pair.
         self._default_tags = {}
         # Keys of tags.
@@ -144,7 +141,7 @@ def __init__(self,
                  description: str = "",
                  tag_keys: Optional[Tuple[str]] = None):
         super().__init__(name, description, tag_keys)
-        self._metric = CythonCount(self._name, self._description, self._unit,
+        self._metric = CythonCount(self._name, self._description,
                                    self._tag_keys)
 
     def __reduce__(self):
@@ -179,8 +176,7 @@ def __init__(self,
                 "Histogram class. e.g., Histogram(boundaries=[1.0, 2.0])")
         self.boundaries = boundaries
         self._metric = CythonHistogram(self._name, self._description,
-                                       self._unit, self.boundaries,
-                                       self._tag_keys)
+                                       self.boundaries, self._tag_keys)
 
     def __reduce__(self):
         deserializer = Histogram
@@ -212,7 +208,7 @@ def __init__(self,
                  description: str = "",
                  tag_keys: Optional[Tuple[str]] = None):
         super().__init__(name, description, tag_keys)
-        self._metric = CythonGauge(self._name, self._description, self._unit,
+        self._metric = CythonGauge(self._name, self._description,
                                    self._tag_keys)
 
     def __reduce__(self):