Fix typecasting and adjust disk io

Netflix-Skunkworks · Jun 3, 2024 · 065069a · 065069a
1 parent 3bbf520
commit 065069a
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Showing 2 changed files with 10 additions and 9 deletions.
diff --git a/service_capacity_modeling/models/common.py b/service_capacity_modeling/models/common.py
@@ -229,8 +229,8 @@ def compute_stateful_zone(
     # Some stateful clusters have preferences on per zone sizing
     cluster_size: Callable[[int], int] = lambda x: x,
     min_count: int = 0,
-    adjusted_disk_io_needed: Optional[float] = 0.0,
-    read_write_ratio: Optional[float] = 0.0
+    adjusted_disk_io_needed: float = 0.0,
+    read_write_ratio: float = 0.0
 ) -> ZoneClusterCapacity:
 
     # Normalize the cores of this instance type to the latency reference
@@ -273,11 +273,13 @@ def compute_stateful_zone(
         disk_per_node = min(max_local_disk_gib, instance.drive.size_gib)
         count = max(count, math.ceil(needed_disk_gib / disk_per_node))
         if adjusted_disk_io_needed != 0.0:
-            instance_read_iops = drive.read_io_per_s
-            instance_write_iops = drive.write_io_per_s
-            instance_adjusted_io = (read_write_ratio * instance_read_iops + \
-                (1.0 - read_write_ratio) * instance_write_iops) * \
-                drive.block_size_kib * 1024.0
+            instance_read_iops = instance.drive.read_io_per_s if instance.drive.read_io_per_s != None else 0
+            assert (isinstance(instance_read_iops, int))
+            instance_write_iops = instance.drive.write_io_per_s if instance.drive.write_io_per_s != None else 0
+            assert (isinstance(instance_write_iops, int))
+            instance_adjusted_io = (read_write_ratio * float(instance_read_iops) + \
+                (1.0 - read_write_ratio) * float(instance_write_iops)) * \
+                instance.drive.block_size_kib * 1024.0
             if instance_adjusted_io != 0.0:
                 count = max(count, math.ceil(adjusted_disk_io_needed / instance_adjusted_io))
 

diff --git a/service_capacity_modeling/models/org/netflix/evcache.py b/service_capacity_modeling/models/org/netflix/evcache.py
@@ -242,8 +242,7 @@ def reserve_memory(instance_mem_gib):
         write_size = desires.query_pattern.estimated_mean_write_size_bytes.mid
         read_disk_io_needed = reads_per_sec * read_size
         write_disk_io_needed = writes_per_sec * write_size
-        adjusted_disk_io_needed = (reads_per_sec * read_disk_io_needed + writes_per_sec * write_disk_io_needed) / \
-            (reads_per_sec + writes_per_sec)
+        adjusted_disk_io_needed = read_disk_io_needed + write_disk_io_needed
         read_write_ratio = reads_per_sec / (reads_per_sec + writes_per_sec)
 
     cluster = compute_stateful_zone(