Remove update_event as a single event loop for the system (#160)

src/api-service/__app__/onefuzzlib/autoscale.py

@@ -0,0 +1,148 @@
+#!/usr/bin/env python
+#
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+import logging
+import math
+from typing import List
+
+from onefuzztypes.enums import NodeState, ScalesetState
+from onefuzztypes.models import AutoScaleConfig, TaskPool
+
+from .pools import Node, Pool, Scaleset
+from .tasks.main import Task
+
+
+def scale_up(pool: Pool, scalesets: List[Scaleset], nodes_needed: int) -> None:
+    logging.info("Scaling up")
+    autoscale_config = pool.autoscale
+    if not isinstance(autoscale_config, AutoScaleConfig):
+        return
+
+    for scaleset in scalesets:
+        if scaleset.state in [ScalesetState.running, ScalesetState.resize]:
+
+            max_size = min(scaleset.max_size(), autoscale_config.scaleset_size)
+            logging.info(
+                "scaleset:%s size:%d max_size:%d"
+                % (scaleset.scaleset_id, scaleset.size, max_size)
+            )
+            if scaleset.size < max_size:
+                current_size = scaleset.size
+                if nodes_needed <= max_size - current_size:
+                    scaleset.size = current_size + nodes_needed
+                    nodes_needed = 0
+                else:
+                    scaleset.size = max_size
+                    nodes_needed = nodes_needed - (max_size - current_size)
+                scaleset.state = ScalesetState.resize
+                scaleset.save()
+
+            else:
+                continue
+
+            if nodes_needed == 0:
+                return
+
+    for _ in range(
+        math.ceil(
+            nodes_needed
+            / min(
+                Scaleset.scaleset_max_size(autoscale_config.image),
+                autoscale_config.scaleset_size,
+            )
+        )
+    ):
+        logging.info("Creating Scaleset for Pool %s" % (pool.name))
+        max_nodes_scaleset = min(
+            Scaleset.scaleset_max_size(autoscale_config.image),
+            autoscale_config.scaleset_size,
+            nodes_needed,
+        )
+
+        if not autoscale_config.region:
+            raise Exception("Region is missing")
+
+        scaleset = Scaleset.create(
+            pool_name=pool.name,
+            vm_sku=autoscale_config.vm_sku,
+            image=autoscale_config.image,
+            region=autoscale_config.region,
+            size=max_nodes_scaleset,
+            spot_instances=autoscale_config.spot_instances,
+            tags={"pool": pool.name},
+        )
+        scaleset.save()
+        nodes_needed -= max_nodes_scaleset
+
+
+def scale_down(scalesets: List[Scaleset], nodes_to_remove: int) -> None:
+    logging.info("Scaling down")
+    for scaleset in scalesets:
+        nodes = Node.search_states(
+            scaleset_id=scaleset.scaleset_id, states=[NodeState.free]
+        )
+        if nodes and nodes_to_remove > 0:
+            max_nodes_remove = min(len(nodes), nodes_to_remove)
+            if max_nodes_remove >= scaleset.size and len(nodes) == scaleset.size:
+                scaleset.state = ScalesetState.shutdown
+                nodes_to_remove = nodes_to_remove - scaleset.size
+                scaleset.save()
+                for node in nodes:
+                    node.set_shutdown()
+                continue
+
+            scaleset.size = scaleset.size - max_nodes_remove
+            nodes_to_remove = nodes_to_remove - max_nodes_remove
+            scaleset.state = ScalesetState.resize
+            scaleset.save()
+
+
+def get_vm_count(tasks: List[Task]) -> int:
+    count = 0
+    for task in tasks:
+        task_pool = task.get_pool()
+        if (
+            not task_pool
+            or not isinstance(task_pool, Pool)
+            or not isinstance(task.config.pool, TaskPool)
+        ):
+            continue
+        count += task.config.pool.count
+    return count
+
+
+def autoscale_pool(pool: Pool) -> None:
+    logging.info("autoscale: %s" % (pool.autoscale))
+    if not pool.autoscale:
+        return
+
+    # get all the tasks (count not stopped) for the pool
+    tasks = Task.get_tasks_by_pool_name(pool.name)
+    logging.info("Pool: %s, #Tasks %d" % (pool.name, len(tasks)))
+
+    num_of_tasks = get_vm_count(tasks)
+    nodes_needed = max(num_of_tasks, pool.autoscale.min_size)
+    if pool.autoscale.max_size:
+        nodes_needed = min(nodes_needed, pool.autoscale.max_size)
+
+    # do scaleset logic match with pool
+    # get all the scalesets for the pool
+    scalesets = Scaleset.search_by_pool(pool.name)
+    pool_resize = False
+    for scaleset in scalesets:
+        if scaleset.state in ScalesetState.modifying():
+            pool_resize = True
+            break
+        nodes_needed = nodes_needed - scaleset.size
+
+    if pool_resize:
+        return
+
+    logging.info("Pool: %s, #Nodes Needed: %d" % (pool.name, nodes_needed))
+    if nodes_needed > 0:
+        # resizing scaleset or creating new scaleset.
+        scale_up(pool, scalesets, nodes_needed)
+    elif nodes_needed < 0:
+        scale_down(scalesets, abs(nodes_needed))