--- id: "bug-1955" status: "open" status_updated: "2026-10-10" status_note: "newly logged" component: "worker" severity: "wrong-result" timestamp: "2026-10-10T08:46:10Z" last_seen: "2026-10-10T08:46:10Z" occurrences: 1 files: ["src/worker/src/controller_connector.c"] tags: ["worker", "job-control", "parallel", "signal"] related: ["bug-1942", "bug-1908"] --- # bug-1955: xcecd drops a signal for a remote task of a multi-host job that is still starting ## Description **Observed:** (source reading, 2026-10-10; found while fixing bug-1942) Only the head host's job start opens the pending-signal window (`pending_signal_start(d->jobid)`, `src/worker/src/controller_connector.c:1062`, bug-1908). The runtasks handler for remote tasks (`handle_runtasks()`, `:1147`) never does, so a signal that arrives before the remote task's worker entry is registered is logged and dropped: ```c XCECD_LOG(XCE_LOG_ERROR, "Failed to find worker for job ID: %s", jobidStr); FREEUP(task_ctx); return -1; /* controller_connector.c:1606 */ ``` Since bug-1942 every host of a multi-host job receives job control, so this window is now reachable. **Expected:** like the head host (bug-1908), a signal for a remote task that is starting is kept and delivered once the task runs. **Impact:** wrong result: a kill or stop sent right after a multi-host job starts can miss some of its remote tasks, which keep running. **Found by:** review of the bug-1940/1942 fixes, 2026-10-10. ## Environment - OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64 - libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2) - Toolchain: gcc (GCC) 15.2.0, meson 1.9.1 - Build: asan (xce.build) - Code: scheduler-framework @ 8568c8ab-dirty - Deployment: real `xcecd` worker (systemd/dbus); multi-host for the remote-task case ## Reproduction 1. Submit a multi-host job (e.g. `/xce-test-multihost` topology) and kill it immediately after dispatch. 2. A remote host logs "Failed to find worker for job ID" and its task keeps running. - Frequency: deterministic by code reading (not yet run) - Evidence: the code quoted in Description; no logs kept. ## Root cause TODO: required for fixed/partial ## Fix TODO: required for fixed/partial ## Verification - Test: TODO: name + file; RED before the fix, GREEN after - Suites: TODO: suite results and build profile - Live: TODO: soak/deploy run, or n/a and why ## References - Related: none