File size: 7,091 Bytes
f5b825d 20769ca f5b825d 20769ca f5b825d 20769ca f5b825d 20769ca f5b825d 20769ca f5b825d 20769ca f5b825d 20769ca f5b825d 84ff88c f5b825d 84ff88c f5b825d 84ff88c f5b825d 84ff88c f5b825d 84ff88c f5b825d 84ff88c f5b825d 84ff88c f5b825d 20769ca 84ff88c f5b825d 20769ca f5b825d 84ff88c f5b825d 84ff88c f5b825d | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 | """
Policy Engine for Automated Healing Actions.
"""
import threading
import logging
import datetime
from collections import OrderedDict
from typing import Dict, List, Optional, Any
from agentic_reliability_framework.core.models.event import HealingPolicy, HealingAction, ReliabilityEvent, PolicyCondition
logger = logging.getLogger(__name__)
DEFAULT_HEALING_POLICIES = [
HealingPolicy(
name="high_latency_restart",
conditions=[PolicyCondition(metric="latency_p99", operator="gt", threshold=500.0)],
actions=[HealingAction.RESTART_CONTAINER, HealingAction.ALERT_TEAM],
priority=1,
cool_down_seconds=300,
max_executions_per_hour=5
),
HealingPolicy(
name="critical_error_rate_rollback",
conditions=[PolicyCondition(metric="error_rate", operator="gt", threshold=0.3)],
actions=[HealingAction.ROLLBACK, HealingAction.CIRCUIT_BREAKER, HealingAction.ALERT_TEAM],
priority=1,
cool_down_seconds=600,
max_executions_per_hour=3
),
HealingPolicy(
name="high_error_rate_traffic_shift",
conditions=[PolicyCondition(metric="error_rate", operator="gt", threshold=0.15)],
actions=[HealingAction.TRAFFIC_SHIFT, HealingAction.ALERT_TEAM],
priority=2,
cool_down_seconds=300,
max_executions_per_hour=5
),
HealingPolicy(
name="resource_exhaustion_scale",
conditions=[
PolicyCondition(metric="cpu_util", operator="gt", threshold=0.9),
PolicyCondition(metric="memory_util", operator="gt", threshold=0.9)
],
actions=[HealingAction.SCALE_OUT],
priority=2,
cool_down_seconds=600,
max_executions_per_hour=10
),
HealingPolicy(
name="moderate_latency_circuit_breaker",
conditions=[PolicyCondition(metric="latency_p99", operator="gt", threshold=300.0)],
actions=[HealingAction.CIRCUIT_BREAKER],
priority=3,
cool_down_seconds=180,
max_executions_per_hour=8
)
]
class PolicyEngine:
"""
Thread‑safe policy engine with cooldown and rate limiting.
Policies are evaluated in priority order. Each policy has:
- conditions (AND logic)
- cooldown per (policy, component)
- rate limit per hour
The engine maintains an LRU cache of last execution timestamps
(using OrderedDict) to bound memory usage.
"""
def __init__(
self,
policies: Optional[List[HealingPolicy]] = None,
max_cooldown_history: int = 10000,
max_execution_history: int = 1000
):
"""
Args:
policies: List of HealingPolicy objects. If None, DEFAULT_HEALING_POLICIES used.
max_cooldown_history: Maximum number of (policy, component) entries to keep.
max_execution_history: Maximum number of timestamps stored per policy for rate limiting.
"""
self.policies = policies or DEFAULT_HEALING_POLICIES
self._lock = threading.RLock()
# OrderedDict acts as an LRU cache: last item is most recent.
self.last_execution: OrderedDict[str, float] = OrderedDict()
self.max_cooldown_history = max_cooldown_history
self.execution_timestamps: Dict[str, List[float]] = {}
self.max_execution_history = max_execution_history
self.policies = sorted(self.policies, key=lambda p: p.priority)
logger.info(f"Initialized PolicyEngine with {len(self.policies)} policies")
def evaluate_policies(self, event: ReliabilityEvent) -> List[HealingAction]:
"""
Evaluate all policies against the event and return the set of actions
triggered (deduplicated). Returns [NO_ACTION] if none triggered.
"""
applicable_actions = []
current_time = datetime.datetime.now(datetime.timezone.utc).timestamp()
for policy in self.policies:
if not policy.enabled:
continue
policy_key = f"{policy.name}_{event.component}"
with self._lock:
last_exec = self.last_execution.get(policy_key, 0)
if current_time - last_exec < policy.cool_down_seconds:
continue
if self._is_rate_limited(policy_key, policy, current_time):
continue
if self._evaluate_conditions(policy.conditions, event):
applicable_actions.extend(policy.actions)
# Update cooldown
self.last_execution[policy_key] = current_time
self.last_execution.move_to_end(policy_key) # mark as most recent
# Enforce cache size
if len(self.last_execution) > self.max_cooldown_history:
self.last_execution.popitem(last=False)
self._record_execution(policy_key, current_time)
# Deduplicate actions while preserving order
seen = set()
unique = []
for a in applicable_actions:
if a not in seen:
seen.add(a)
unique.append(a)
return unique if unique else [HealingAction.NO_ACTION]
def _evaluate_conditions(self, conditions: List[PolicyCondition], event: ReliabilityEvent) -> bool:
"""Return True if all conditions are satisfied."""
for cond in conditions:
metric = cond.metric
op = cond.operator
thresh = cond.threshold
val = getattr(event, metric, None)
if val is None:
return False
if op == "gt":
if not (val > thresh):
return False
elif op == "lt":
if not (val < thresh):
return False
elif op == "eq":
if not (abs(val - thresh) < 1e-6):
return False
elif op == "gte":
if not (val >= thresh):
return False
elif op == "lte":
if not (val <= thresh):
return False
else:
return False
return True
def _is_rate_limited(self, key: str, policy: HealingPolicy, now: float) -> bool:
"""Check if the policy has exceeded its hourly execution limit."""
if key not in self.execution_timestamps:
return False
one_hour_ago = now - 3600
recent = [ts for ts in self.execution_timestamps[key] if ts > one_hour_ago]
self.execution_timestamps[key] = recent
return len(recent) >= policy.max_executions_per_hour
def _record_execution(self, key: str, ts: float):
"""Record an execution timestamp for rate limiting."""
if key not in self.execution_timestamps:
self.execution_timestamps[key] = []
self.execution_timestamps[key].append(ts)
if len(self.execution_timestamps[key]) > self.max_execution_history:
self.execution_timestamps[key] = self.execution_timestamps[key][-self.max_execution_history:] |