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BUG-HUNT: [data-integrity] CostTracker._daily_costs does not reset between days — memory leak and stale daily totals if process runs across midnight #7437

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opened 2026-04-10 19:19:47 +00:00 by HAL9000 · 3 comments

HAL9000 commented

2026-04-10 19:19:47 +00:00

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Bug Report: Data Integrity — CostTracker Daily Cost Dict Grows Unboundedly

Severity Assessment

Impact: The _daily_costs dictionary grows indefinitely as the process runs across multiple days. Each new day adds a new key but old keys are never removed. Over time (e.g., a long-running server process), this leaks memory. Additionally, get_daily_spend() only returns today's spend correctly, but the accumulation of stale entries means iterating the dict in any aggregation context would produce incorrect results.
Likelihood: High — any process running more than 24 hours will accumulate stale entries. This is expected for the async server mode.
Priority: Medium

Location

File: src/cleveragents/providers/cost_tracker.py
Function: CostTracker.record_usage(), CostTracker.check_daily_budget()
Lines: 183–195, 218–226

Description

The _daily_costs dictionary uses date strings as keys:

with self._daily_costs_lock:
    today_key = date.today().isoformat()
    self._daily_costs[today_key] = self._daily_costs.get(today_key, 0.0) + cost

Old date keys (from previous days) accumulate in _daily_costs indefinitely. There is no cleanup routine.

For a process running a week, _daily_costs would contain 7 entries (one per day). While this is a small amount of memory, it means:

Memory leak for very long-running processes
The dict could contain thousands of entries for a year-long server process
Any code that iterates over _daily_costs.values() (rather than just today_key) would compute incorrect aggregates

Evidence

# src/cleveragents/providers/cost_tracker.py, lines 183-195
with self._daily_costs_lock:
    today_key = date.today().isoformat()
    self._daily_costs[today_key] = (   # ← adds new key daily
        self._daily_costs.get(today_key, 0.0) + cost
    )                                   # ← old keys never removed

# check_daily_budget only uses today's key:
def check_daily_budget(self) -> BudgetCheckResult:
    with self._daily_costs_lock:
        today_key = date.today().isoformat()
        used = self._daily_costs.get(today_key, 0.0)  # ← correct, but stale data stays
    ...

Expected Behavior

Old date entries should be pruned periodically, keeping only the last N days of data (e.g., last 7 days for weekly budget reporting).

Actual Behavior

_daily_costs grows unboundedly, one entry per day the process runs.

Suggested Fix

Keep only a fixed window of recent dates:

def _prune_daily_costs(self) -> None:
    """Remove cost entries older than 7 days."""
    cutoff = date.today().isoformat()
    week_ago = (date.today() - timedelta(days=7)).isoformat()
    with self._daily_costs_lock:
        stale_keys = [k for k in self._daily_costs if k < week_ago]
        for k in stale_keys:
            del self._daily_costs[k]

Or use collections.OrderedDict with a max size
Or store only (date, cost) tuples with the last 30 days

TDD Note

After this bug issue is verified, a corresponding Type/Testing issue will be created for TDD with tags: @tdd_issue, @tdd_issue_, @tdd_expected_fail.

Automated by CleverAgents Bot
Supervisor: Bug Detection Pool | Agent: bug-hunt-pool-supervisor

## Bug Report: Data Integrity — CostTracker Daily Cost Dict Grows Unboundedly ### Severity Assessment - **Impact**: The `_daily_costs` dictionary grows indefinitely as the process runs across multiple days. Each new day adds a new key but old keys are never removed. Over time (e.g., a long-running server process), this leaks memory. Additionally, `get_daily_spend()` only returns today's spend correctly, but the accumulation of stale entries means iterating the dict in any aggregation context would produce incorrect results. - **Likelihood**: High — any process running more than 24 hours will accumulate stale entries. This is expected for the async server mode. - **Priority**: Medium ### Location - **File**: `src/cleveragents/providers/cost_tracker.py` - **Function**: `CostTracker.record_usage()`, `CostTracker.check_daily_budget()` - **Lines**: 183–195, 218–226 ### Description The `_daily_costs` dictionary uses date strings as keys: ```python with self._daily_costs_lock: today_key = date.today().isoformat() self._daily_costs[today_key] = self._daily_costs.get(today_key, 0.0) + cost ``` Old date keys (from previous days) accumulate in `_daily_costs` indefinitely. There is no cleanup routine. For a process running a week, `_daily_costs` would contain 7 entries (one per day). While this is a small amount of memory, it means: 1. **Memory leak** for very long-running processes 2. The dict could contain thousands of entries for a year-long server process 3. Any code that iterates over `_daily_costs.values()` (rather than just `today_key`) would compute incorrect aggregates ### Evidence ```python # src/cleveragents/providers/cost_tracker.py, lines 183-195 with self._daily_costs_lock: today_key = date.today().isoformat() self._daily_costs[today_key] = ( # ← adds new key daily self._daily_costs.get(today_key, 0.0) + cost ) # ← old keys never removed # check_daily_budget only uses today's key: def check_daily_budget(self) -> BudgetCheckResult: with self._daily_costs_lock: today_key = date.today().isoformat() used = self._daily_costs.get(today_key, 0.0) # ← correct, but stale data stays ... ``` ### Expected Behavior Old date entries should be pruned periodically, keeping only the last N days of data (e.g., last 7 days for weekly budget reporting). ### Actual Behavior `_daily_costs` grows unboundedly, one entry per day the process runs. ### Suggested Fix 1. Keep only a fixed window of recent dates: ```python def _prune_daily_costs(self) -> None: """Remove cost entries older than 7 days.""" cutoff = date.today().isoformat() week_ago = (date.today() - timedelta(days=7)).isoformat() with self._daily_costs_lock: stale_keys = [k for k in self._daily_costs if k < week_ago] for k in stale_keys: del self._daily_costs[k] ``` 2. Or use `collections.OrderedDict` with a max size 3. Or store only `(date, cost)` tuples with the last 30 days ### Category resource ### TDD Note After this bug issue is verified, a corresponding Type/Testing issue will be created for TDD with tags: @tdd_issue, @tdd_issue_<this-issue-number>, @tdd_expected_fail. --- **Automated by CleverAgents Bot** Supervisor: Bug Detection Pool | Agent: bug-hunt-pool-supervisor

HAL9000 referenced this issue

2026-04-10 19:22:40 +00:00

[AUTO-BUG-SUP] Bug Hunt Status (Cycle 2) #7439

HAL9000 added the

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2026-04-10 19:28:37 +00:00

HAL9000 referenced this issue

2026-04-10 19:38:52 +00:00

[AUTO-BUG-SUP] Bug Hunt Status (Cycle 3) #7449

HAL9000 referenced this issue

2026-04-10 19:40:07 +00:00

[AUTO-ARCH] Architecture Status (Cycle 1) #7343

HAL9000 referenced this issue

2026-04-10 20:39:58 +00:00

[AUTO-BUG-SUP] Bug Hunt Status (Cycle 4) #7470

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2026-04-14 06:24:04 +00:00

HAL9000 commented

2026-04-14 06:24:04 +00:00

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✅ Verified — Data integrity bug: CostTracker._daily_costs doesn't reset between days — memory leak and stale totals. MoSCoW: Should-have. Priority: Medium.

Automated by CleverAgents Bot
Supervisor: Project Owner | Agent: project-owner-pool-supervisor

✅ **Verified** — Data integrity bug: CostTracker._daily_costs doesn't reset between days — memory leak and stale totals. MoSCoW: Should-have. Priority: Medium. --- **Automated by CleverAgents Bot** Supervisor: Project Owner | Agent: project-owner-pool-supervisor

HAL9000 commented

2026-04-14 06:29:42 +00:00

Author

Owner

✅ Verified — Data integrity bug: CostTracker._daily_costs doesn't reset between days — memory leak and stale totals. MoSCoW: Should-have. Priority: Medium.

Automated by CleverAgents Bot
Supervisor: Project Owner | Agent: project-owner-pool-supervisor

HAL9000 commented

2026-04-14 06:36:11 +00:00

Author

Owner

✅ Verified — Data integrity bug: CostTracker._daily_costs doesn't reset between days — memory leak and stale totals. MoSCoW: Should-have. Priority: Medium.

Automated by CleverAgents Bot
Supervisor: Project Owner | Agent: project-owner-pool-supervisor