fix(gateway): raise macOS launchd fd limit to 4096 in generated plist#26536
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aisaacsmitchell wants to merge 1 commit into
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fix(gateway): raise macOS launchd fd limit to 4096 in generated plist#26536aisaacsmitchell wants to merge 1 commit into
aisaacsmitchell wants to merge 1 commit into
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The default macOS per-process open-file limit is 256. The gateway spawns cron-job subprocesses concurrently; under load, file descriptors accumulate across parallel runs and exhaust the limit, causing every subsequent Popen() call to fail with EAGAIN / BlockingIOError. This crashes the gateway and all cron jobs silently until the service is manually restarted. Add HardResourceLimits and SoftResourceLimits (NumberOfFiles: 4096) to generate_launchd_plist() so every hermes gateway install/start/restart produces a plist with an adequate fd ceiling. Both keys are required: SoftResourceLimits is the effective runtime cap; HardResourceLimits is the ceiling the process is permitted to raise itself to. Setting only Soft leaves Hard at the OS default (256), so any call to setrlimit() that tries to raise the soft limit hits the hard wall and fails. 4096 matches the value recommended in the macOS developer documentation for long-running daemons and is consistent with what other gateway daemons (nginx, postgres launchd plists) use as a baseline. Adds two tests to TestLaunchdPlistReplace verifying the keys are present and appear exactly once each.
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What
Add
HardResourceLimitsandSoftResourceLimits(NumberOfFiles: 4096) togenerate_launchd_plist().Why
The default macOS per-process open-file limit is 256. The gateway spawns cron-job subprocesses concurrently; under load, file descriptors accumulate across parallel runs and exhaust the limit, causing every subsequent
Popen()call to fail withEAGAIN/BlockingIOError. This crashes the gateway and all cron jobs silently until the service is manually restarted.Both keys are required:
SoftResourceLimitsis the effective runtime cap.HardResourceLimitsis the ceiling the process is permitted to raise itself to viasetrlimit(). Setting onlySoftleavesHardat the OS default (256), so any code that callssetrlimit()to raise the soft limit hits the hard wall and fails.4096 matches the value recommended in the macOS developer documentation for long-running daemons and is consistent with what nginx, postgres, and other launchd-managed services use as a baseline.
How to test
Or:
pytest tests/hermes_cli/test_update_gateway_restart.py::TestLaunchdPlistReplace -vPlatforms tested
macOS (Sonoma 15.x, Apple Silicon). Change is plist-only — no effect on Linux (systemd) or Windows paths.