fix: disable HTTP response caching to prevent unbounded memory growth

[devin-ai-integration]

fix: disable HTTP response caching to prevent unbounded memory growth

Summary

Hardcodes _use_cache = False in HttpClient.__init__ to disable the requests_cache SQLite-backed HTTP response cache entirely. This prevents unbounded memory growth observed during long-running syncs where the SQLite cache accumulates responses in memory without bound.

Root cause investigation: During sandbox testing of source-twilio, container memory grew from ~300 MB to 8 GB over a few hours. After systematically ruling out Python heap leaks (memray showed constant ~300 MB), malloc fragmentation (jemalloc didn't help), and OS page cache (in-memory SQLite eliminated the RSS/working-set gap but RSS itself still grew), the cause was traced to requests_cache's SQLite backend accumulating cached HTTP responses. Even with TTL expiration and active purging, the cache grew unboundedly for connectors making thousands of unique paginated API calls. Disabling cache entirely confirmed stable memory at ~300 MB.

Scope: This is a global change — all connectors using HttpClient with use_cache=True will now have caching silently disabled. The use_cache constructor parameter is still accepted but ignored.

6 cache-related tests are skipped across 3 test files since they assert caching behavior that is now disabled.

Review & Testing Checklist for Human

• Confirm global scope is acceptable: This disables caching for ALL connectors, not just Twilio. Connectors that rely on use_cache=True to deduplicate API calls (e.g., parent streams read by multiple child streams) will now make redundant HTTP requests. Evaluate whether any connectors depend on caching for correctness or have rate-limit-sensitive APIs where extra calls could cause failures.
• Evaluate impact on sync performance: Connectors using caching to avoid re-fetching parent stream data will now re-fetch on every access. Check if this causes meaningful slowdowns or API quota issues for high-volume connectors.
• Plan for permanent fix: The change is marked TEMPORARY. Decide on a proper fix — options include bounded LRU cache, stream-scoped cache with size limits, or removing the caching feature entirely and updating the use_cache API surface.
• Verify skipped tests are tracked: 6 tests are skipped. Ensure there's a tracking issue to either re-enable them when caching is reintroduced or remove them if caching is permanently dropped.

Notes

• The use_cache parameter on HttpClient.__init__ is now dead code — it's accepted but always overridden to False. Consider whether to keep the parameter (for future re-enablement) or remove it to avoid confusion.
• Comment in code references PR feat: add ddtrace, in-memory cache, and cache TTL to source-declarative-manifest image #932 which was the experimental investigation PR, not this clean PR.
• Requested by: gl_anatolii.yatsuk
• Link to Devin Session

---

[devin-ai-integration]

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Testing This CDK Version

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# Run the CLI from this branch:
uvx 'git+https://github.com/airbytehq/airbyte-python-cdk.git@devin/1773351139-disable-http-cache#egg=airbyte-python-cdk[dev]' --help

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poe use-cdk-branch devin/1773351139-disable-http-cache

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

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[github-actions]

PyTest Results (Fast)

3 934 tests  ±0   3 915 ✅  - 7   7m 12s ⏱️ +3s
    1 suites ±0      19 💤 +7 
    1 files   ±0       0 ❌ ±0 

Results for commit fd49a15. ± Comparison against base commit 0e57414.

This pull request skips 7 tests.

unit_tests.sources.streams.http.test_http ‑ test_that_response_was_cached
unit_tests.sources.streams.http.test_http ‑ test_using_cache
unit_tests.sources.streams.http.test_http_client ‑ test_given_different_headers_then_response_is_not_cached
unit_tests.sources.streams.http.test_http_client ‑ test_request_session_returns_valid_session[False-LimiterSession]
unit_tests.sources.streams.http.test_http_client ‑ test_request_session_returns_valid_session[True-CachedLimiterSession]
unit_tests.sources.streams.http.test_http_client ‑ test_that_response_was_cached
unit_tests.sources.streams.test_call_rate.TestHttpStreamIntegration ‑ test_with_cache

[github-actions]

PyTest Results (Full)

3 937 tests  ±0   3 918 ✅  - 7   11m 18s ⏱️ +4s
    1 suites ±0      19 💤 +7 
    1 files   ±0       0 ❌ ±0 

Results for commit fd49a15. ± Comparison against base commit 0e57414.

This pull request skips 7 tests.

unit_tests.sources.streams.http.test_http ‑ test_that_response_was_cached
unit_tests.sources.streams.http.test_http ‑ test_using_cache
unit_tests.sources.streams.http.test_http_client ‑ test_given_different_headers_then_response_is_not_cached
unit_tests.sources.streams.http.test_http_client ‑ test_request_session_returns_valid_session[False-LimiterSession]
unit_tests.sources.streams.http.test_http_client ‑ test_request_session_returns_valid_session[True-CachedLimiterSession]
unit_tests.sources.streams.http.test_http_client ‑ test_that_response_was_cached
unit_tests.sources.streams.test_call_rate.TestHttpStreamIntegration ‑ test_with_cache

[Anatolii Yatsuk (tolik0)]

/prerelease

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