fix: SQLite busy_timeout + z620 SSH via worker relay

- db(): timeout=30 + PRAGMA busy_timeout=5000 pour éviter locked sous charge parallèle
- _ssh_via(): helper routant SSH z620 via worker (.82→worker→z620)
- _extract_on_remote_host(): toutes les commandes z620 passent via worker
- resume probe: ffprobe z620 également via worker
- reset jobs 11/17/18/20 en queued pour relancer

scripts/dispatcher.py

@@ -65,8 +65,9 @@ _reserved_vram = {w["host"]: 0 for w in WORKERS}
 
 
 def db() -> sqlite3.Connection:
-    conn = sqlite3.connect(DB_PATH, isolation_level=None)
+    conn = sqlite3.connect(DB_PATH, isolation_level=None, timeout=30)
     conn.execute("PRAGMA journal_mode=WAL")
+    conn.execute("PRAGMA busy_timeout = 5000")
     conn.row_factory = sqlite3.Row
     return conn
 
@@ -367,6 +368,13 @@ def ensure_worker_video_source(video_path: str, worker: dict, worker_src: str, i
 
 
 
+
+def _ssh_via(worker: dict, host: str, cmd: str, timeout: int = 30) -> tuple[int, str, str]:
+    """Route SSH to host through worker as relay (z620 not directly reachable from .82)."""
+    relay = "ssh -o BatchMode=yes -o ConnectTimeout=5 -o StrictHostKeyChecking=accept-new " + host + " " + shlex.quote(cmd)
+    return ssh(worker["ssh_alias"], relay, timeout=timeout)
+
+
 def _extract_on_remote_host(job_id: int, worker: dict, src_host: str, src_path: str,
                               frames_dir: str, vid_num: int, n_videos: int,
                               idx: int, vf: str) -> tuple[int, float]:
@@ -377,7 +385,7 @@ def _extract_on_remote_host(job_id: int, worker: dict, src_host: str, src_path:
     pattern = f"{remote_tmp}/frame_%06d.jpg"
     exit_file = f"/tmp/cosma-ffmpeg-remote-{job_id}-{vid_num}.exit"
 
-    _, dur_str, _ = ssh(src_host,
+    _, dur_str, _ = _ssh_via(worker, src_host,
         f"ffprobe -v error -show_entries format=duration -of csv=p=0 "
         f"{shlex.quote(src_path)} 2>/dev/null || echo 0", timeout=30)
     try:
@@ -386,7 +394,7 @@ def _extract_on_remote_host(job_id: int, worker: dict, src_host: str, src_path:
         dur = 0.0
     frames_est = max(1, int(dur * FPS))
 
-    ssh(src_host, f"mkdir -p {shlex.quote(remote_tmp)}")
+    _ssh_via(worker, src_host, f"mkdir -p {shlex.quote(remote_tmp)}")
     bg = (
         f"rm -f {shlex.quote(exit_file)}; "
         f"ffmpeg -hide_banner -loglevel error -i {shlex.quote(src_path)} "
@@ -394,12 +402,12 @@ def _extract_on_remote_host(job_id: int, worker: dict, src_host: str, src_path:
         f"</dev/null >/tmp/cosma-ffmpeg-remote-{job_id}.log 2>&1; "
         f"echo $? > {shlex.quote(exit_file)}"
     )
-    ssh(src_host, f"setsid bash -c {shlex.quote(bg)} >/dev/null 2>&1 &")
+    _ssh_via(worker, src_host, f"setsid bash -c {shlex.quote(bg)} >/dev/null 2>&1 &")
     print(f"  ffmpeg running on {src_host} for {Path(src_path).name}...")
 
     while True:
-        rc_done = ssh(src_host, f"test -s {shlex.quote(exit_file)}", timeout=10)[0]
+        rc_done = _ssh_via(worker, src_host, f"test -s {shlex.quote(exit_file)}", timeout=10)[0]
-        _, count_str, _ = ssh(src_host,
+        _, count_str, _ = _ssh_via(worker, src_host,
             f"ls {shlex.quote(remote_tmp)}/frame_*.jpg 2>/dev/null | wc -l", timeout=10)
         current_remote = int(count_str.strip()) if count_str.strip().isdigit() else 0
         current_worker = count_frames(worker, frames_dir)
@@ -411,10 +419,10 @@ def _extract_on_remote_host(job_id: int, worker: dict, src_host: str, src_path:
             break
         time.sleep(5)
 
-    _, code_str, _ = ssh(src_host, f"cat {shlex.quote(exit_file)} 2>/dev/null || echo 1")
+    _, code_str, _ = _ssh_via(worker, src_host, f"cat {shlex.quote(exit_file)} 2>/dev/null || echo 1")
     rc = int(code_str.strip()) if code_str.strip().isdigit() else 1
     if rc != 0:
-        _, err, _ = ssh(src_host, f"cat /tmp/cosma-ffmpeg-remote-{job_id}.log 2>/dev/null | tail -5 || echo ''")
+        _, err, _ = _ssh_via(worker, src_host, f"cat /tmp/cosma-ffmpeg-remote-{job_id}.log 2>/dev/null | tail -5 || echo ''")
         raise RuntimeError(f"ffmpeg on {src_host} failed: {err[:200]}")
 
     set_status(job_id, step=f"scp frames {vid_num}/{n_videos} -> {worker['host']}")
@@ -428,7 +436,7 @@ def _extract_on_remote_host(job_id: int, worker: dict, src_host: str, src_path:
     if rc2 != 0:
         raise RuntimeError(f"scp frames {src_host}->{worker['host']} failed: {err2[:200]}")
 
-    ssh(src_host, f"rm -rf {shlex.quote(remote_tmp)}", timeout=60)
+    _ssh_via(worker, src_host, f"rm -rf {shlex.quote(remote_tmp)}", timeout=60)
     new_idx = count_frames(worker, frames_dir)
     return new_idx, dur
 
@@ -482,7 +490,7 @@ def do_extract(job: sqlite3.Row, worker: dict) -> str:
             _vpath = v.split(':', 1)[1] if ':' in v and not v.startswith('/') else v
             _vhost = v.split(':', 1)[0] if ':' in v and not v.startswith('/') else worker['ssh_alias']
             _dur_alias = _vhost if _vhost in (worker['ssh_alias'], worker['host']) else _vhost
-            _, _dur_str, _ = ssh(_dur_alias,
+            _, _dur_str, _ = _ssh_via(worker, _dur_alias,
                 f"ffprobe -v error -show_entries format=duration -of csv=p=0 "
                 f"{shlex.quote(_vpath)} 2>/dev/null || echo 0", timeout=30)
             _dur = float(_dur_str.strip()) if _dur_str.strip() else 0.0