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fix(controller): persist dispatch-time resource allocation into WAL_JOB_DISPATCH (bug-1678, gitea #43)

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dispatch_a_job_() set j->job.allocs in memory at dispatch-commit time
but only ever persisted {jobid, state} via persist_submit_job_fact() --
the allocation itself was never written to the WAL. On a full restart,
job.state correctly recovered to RUN (both WAL_JOB_DISPATCH and the
later WAL_JOB_START fact carry state=RUN) but job.allocs stayed
permanently NULL, since apply_job_update_transition() only ever
touches state. EXEC_HOST displayed blank forever for a job that was
genuinely running before shutdown.

No capnp schema change needed -- JobAlloc (xce_job_alloc_t) was
already a full top-level struct (the existing Job.allocs field) with
generated encode/decode functions already in the build. New:
capnp_encode_joballoc()/decode_joballoc() (persist.c, mirroring the
existing capnp_encode_worker()/restore_job() patterns) and
persist_submit_job_dispatch_fact() -- WAL_JOB_DISPATCH's payload is
now a wal_jobstate_t header plus trailing capnp-encoded JobAlloc
bytes. dispatch_a_job_() now persists j->job.allocs (the canonical,
freshly-constructed struct, read under the same write lock) instead
of just the state.

Both apply seams updated: apply_committed_entry() (primary's own boot
replay) gets one added branch in its existing WAL_JOB_START/FINISH
stamp-chain; apply_wal_entry() (standby catch-up / replicated-apply --
also required, a promoted standby would hit the identical bug) has
WAL_JOB_DISPATCH split into its own case, calling new
restore_job_dispatch_state(). A payload of exactly sizeof(wal_jobstate_t)
(any entry written before this fix) decodes no allocation and behaves
exactly as before -- full backward compatibility.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AgYRU3zDTqNGV5Jk8aiKLg
This commit is contained in:
Rongsong Shen 2026-08-25 03:12:49 +00:00
parent 2a24551542
commit db142d415f
No known key found for this signature in database
GPG key ID: 5BCDAAE0123E9FE2
4 changed files with 205 additions and 7 deletions
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145
src/controller/persist.c
View file

@ -34,6 +34,14 @@
extern int restore_job(cluster_t* c, uint64_t jobid, const void* capnp_payload,
size_t len, uint64_t entry_lsn);
extern int restore_job_state(cluster_t* c, uint64_t jobid, uint32_t state);
/* restore_job_dispatch_state defined in job.c (bug-1678): WAL_JOB_DISPATCH's
* own sibling of restore_job_state() above, additionally taking ownership of
* an optional decoded xce_job_alloc_t so the dispatch-time resource
* allocation survives standby catch-up / replicated-apply the same way
* apply_committed_entry's WAL_JOB_DISPATCH case already restores it on the
* primary's own boot replay. */
extern int restore_job_dispatch_state(cluster_t* c, uint64_t jobid,
uint32_t state, xce_job_alloc_t* alloc);
extern int worker_from_capnp(cluster_t* c,
const void* capnp_payload, size_t len);
extern int restore_queue_state(cluster_t* c,
@ -134,6 +142,62 @@ static int capnp_encode_worker(const xce_worker_t* w, uint8_t** out, size_t* out
return 0;
}
/* Serialize xce_job_alloc_t to a malloc'd Cap'n Proto buffer (bug-1678):
* lets WAL_JOB_DISPATCH carry the scheduler's resource allocation alongside
* the {jobid, state} header, so a restart replay can reconstruct it instead
* of leaving job.allocs permanently NULL. Mirrors capnp_encode_worker above
* exactly, using the JobAlloc struct (already in controller.capnp as the
* existing Job.allocs field -- no schema change needed here). */
static int capnp_encode_joballoc(const xce_job_alloc_t* a, uint8_t** out,
size_t* out_len)
{
struct capn c;
struct capn_segment* cs;
struct JobAlloc cja;
JobAlloc_ptr jap;
capn_init_malloc(&c);
cs = capn_root(&c).seg;
encode_JobAlloc(cs, &cja, (xce_job_alloc_t*)a);
jap = new_JobAlloc(cs);
write_JobAlloc(&cja, jap);
capn_setp(capn_root(&c), 0, jap.p);
*out_len = capn_size(&c);
*out = malloc(*out_len);
if (!*out) { capn_free(&c); return -ENOMEM; }
capn_write_mem(&c, *out, *out_len, 0);
capn_free(&c);
return 0;
}
/* Decode a Cap'n Proto JobAlloc buffer (bug-1678) into a freshly heap-
* allocated xce_job_alloc_t*, mirroring restore_job()'s Job decode pattern
* (job.c) but returning the struct directly instead of constructing a job.
* Returns NULL on a NULL/empty payload; caller owns the result (release via
* free_JobAlloc_ptr). */
static xce_job_alloc_t* decode_joballoc(const uint8_t* payload, size_t len)
{
struct capn c_ctx;
JobAlloc_ptr jap;
struct JobAlloc cja;
xce_job_alloc_t* alloc;
if (!payload || len == 0)
return NULL;
capn_init_mem(&c_ctx, payload, len, 0);
jap.p = capn_getp(capn_root(&c_ctx), 0, 1);
memset(&cja, 0, sizeof(cja));
read_JobAlloc(&cja, jap);
alloc = calloc(1, sizeof(*alloc));
if (!alloc) { capn_free(&c_ctx); return NULL; }
decode_JobAlloc(alloc, &cja);
capn_free(&c_ctx);
return alloc;
}
/* Serialize a host admin-state frame (config-upgrade-snapshot task 2.1, Req
* 1.6/1.7/1.9) to a malloc'd Cap'n Proto buffer. Mirrors capnp_encode_job
* above exactly -- capnp_host_admin_state_t (typemap.h) is a frame-only
@ -3458,7 +3522,6 @@ int apply_wal_entry(persist_t* p, uint32_t type, uint64_t lsn,
case WAL_JOB_CKPT:
case WAL_JOB_PREASON:
case WAL_JOB_RUSAGE:
case WAL_JOB_DISPATCH:
/* Payload: wal_jobstate_t {jobid, state} */
if (payload_len >= sizeof(wal_jobstate_t)) {
const wal_jobstate_t* js = (const wal_jobstate_t*)payload;
@ -3466,6 +3529,30 @@ int apply_wal_entry(persist_t* p, uint32_t type, uint64_t lsn,
}
break;
case WAL_JOB_DISPATCH: {
/* bug-1678: split out of the shared group above -- this is the one
* fact type whose payload can carry a trailing Cap'n Proto JobAlloc
* (persist_submit_job_dispatch_fact's shape) alongside the
* {jobid, state} header, so a promoted standby's catch-up replay
* recovers the dispatch-time resource allocation too, not just the
* state. A payload of exactly sizeof(wal_jobstate_t) (no trailing
* bytes -- any WAL_JOB_DISPATCH entry written before this fix)
* decodes no allocation, matching the pre-fix state-only behavior
* exactly. */
if (payload_len >= sizeof(wal_jobstate_t)) {
const wal_jobstate_t* js = (const wal_jobstate_t*)payload;
xce_job_alloc_t* alloc = NULL;
if (payload_len > sizeof(wal_jobstate_t)) {
alloc = decode_joballoc(
(const uint8_t*)payload + sizeof(wal_jobstate_t),
payload_len - sizeof(wal_jobstate_t));
}
restore_job_dispatch_state(p->cluster, js->jobid, js->state,
alloc);
}
break;
}
case WAL_WORKER_CTRL:
/* Payload: [uint32_t detail][capnp worker] */
if (payload_len > WORKER_WAL_HDR_SIZE)
@ -3752,6 +3839,24 @@ int apply_committed_entry(persist_t* p, uint32_t wal_type, uint64_t lsn,
} else if (wal_type == WAL_JOB_FINISH) {
j->job.finish_time = time(NULL);
j->job.run_time = (int)(j->job.finish_time - j->job.start_time);
} else if (wal_type == WAL_JOB_DISPATCH
&& len > sizeof(wal_jobstate_t)) {
/* bug-1678: trailing bytes beyond the header carry the
* scheduler's resource allocation (persist_submit_job_
* dispatch_fact's payload shape) -- decode and adopt it so
* a restart replay recovers EXEC_HOST, not just STATUS. A
* payload of exactly sizeof(wal_jobstate_t) (no trailing
* bytes -- e.g. any WAL_JOB_DISPATCH entry written before
* this fix) intentionally falls through to the same
* state-only behavior every other type in this group gets. */
xce_job_alloc_t* decoded = decode_joballoc(
(const uint8_t*)payload + sizeof(wal_jobstate_t),
len - sizeof(wal_jobstate_t));
if (decoded != NULL) {
if (j->job.allocs != NULL)
free_JobAlloc_ptr(&(j->job.allocs));
j->job.allocs = decoded;
}
}
}
unlock(j);
@ -6712,6 +6817,44 @@ int persist_submit_job_fact_ex(persist_t* p, uint32_t wal_type,
sizeof(js));
}
/* bug-1678: WAL_JOB_DISPATCH's own richer sibling of persist_submit_job_fact()
* -- the ONLY job-state fact type that needs to carry a resource allocation
* alongside {jobid, state}, since it is the sole durable record of the
* dispatch-time PEND->RUN transition (design.md "WAL Dispatch Fact"). Payload
* shape: wal_jobstate_t header immediately followed by the Cap'n Proto-
* encoded JobAlloc bytes -- apply_committed_entry()'s and apply_wal_entry()'s
* WAL_JOB_DISPATCH cases decode exactly this shape, and treat a payload of
* exactly sizeof(wal_jobstate_t) (no trailing bytes) as "state-only, leave
* allocs untouched" for backward compatibility with any WAL_JOB_DISPATCH
* entry written before this fix. */
int persist_submit_job_dispatch_fact(persist_t* p, uint64_t jobid, int state,
const xce_job_alloc_t* alloc)
{
wal_jobstate_t js = { .jobid = jobid, .state = (uint32_t)state,
._pad = 0 };
uint8_t* allocbuf = NULL;
size_t alloclen = 0;
uint8_t* payload;
size_t total;
int rc;
rc = capnp_encode_joballoc(alloc, &allocbuf, &alloclen);
if (rc != 0)
return rc;
total = sizeof(js) + alloclen;
payload = malloc(total);
if (!payload) { free(allocbuf); return -ENOMEM; }
memcpy(payload, &js, sizeof(js));
memcpy(payload + sizeof(js), allocbuf, alloclen);
free(allocbuf);
rc = wal_hook_append_classified(p, WAL_JOB_DISPATCH, WAL_MODE_RETAIN,
payload, (uint32_t)total);
free(payload);
return rc;
}
/* P0 payload: just the detail value (4 bytes).
* Full Cap'n Proto serialization is wired in Task 15. */