wdgzyjx/myxce
1
0
Fork 0
forked from lei.chen/myxce
Code Pull requests Activity

feat(raft-drive-async): snapshot SlowLane offload + WAL-trim cursor guard (task 3.2)

Browse source 
Part B (LIVE, default-ON): trim_wal_segments now bounds WAL-segment deletion
by repl_trim_lsn(&p->repl, active_seg_lsn) = min(active segment LSN, every
active standby acked_lsn, every valid disconnected-slot last_disconnected_lsn),
after repl_expire_disconnect_slots ages out stale slot guards. floor <=
active_seg_lsn structurally, so the guard can only preserve more segments,
never delete one a live standby still needs — closes the bug-795/828
trim-vs-cursor race for connected/recently-disconnected standbys (bug-1147
stopgap; empty/cursor=0 join still needs entity-bearing snapshots).

Part A (DORMANT, g_drive_async_snapshot_offload default OFF): ha_snapshot_send_
dispatch routes HA_REPL_SEND_SNAPSHOT inline (flag OFF — byte-for-byte legacy,
on io_worker) or to slowlane_submit+snapshot_lane_fn (flag ON). Send body
factored into ha_snapshot_do_send. Per-peer single-flight via
ha_state_t.snapshot_inflight[] CAS + slowlane key; in-flight flag cleared on
all four terminal paths, mirroring the reconnect offload (task 2.1).

Lands dormant like task 3.1: snapshot_lane_fn borrows a standby endpoint it
does not own, so flag-ON would race io_worker RDHUP teardown (cross-thread UAF,
bug-1197 family). Flag OFF keeps send+teardown serialized on the io_worker.
Task 3.4 is the single gate that flips both this and the peerctrl flag ON after
establishing endpoint-lifetime discipline; bug-1198 stays open by design until
then. The offload flag was initially authored default-ON (would ship the UAF)
and corrected to OFF in ha.c and the ha.h accessor doc (bug-1210).

Tests (controller 196/0, 0 new leaks): test_snapshot_offload_runs_on_lane,
test_snapshot_inline_when_flag_off, test_snapshot_offload_dedups_per_peer,
test_trim_guard_preserves_standby_segments,
test_trim_without_standbys_proceeds_normally. Adversarial cpp-review: GO.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6fDCtXkkEgupu7rUah1y2
This commit is contained in:
Rongsong Shen 2026-06-26 15:43:24 +00:00
parent e17a6a613c
commit 6c0523b69b
8 changed files with 2046 additions and 850 deletions
Download patch file Download diff file Expand all files Collapse all files

147
src/controller/testsuite/test_e2e_checkpoint.c
View file

@ -21,6 +21,24 @@
#include "config.h"
#include "persist.h"
#include "repl.h" /* repl_add_standby / repl_on_ack for trim-guard tests
* (raft-drive-async task 3.2, bug-1147) */
#include "typemap.h" /* wal_catchup_entry_t */
/* Drop hook for repl_broadcast: fixtures with dummy (int) endpoints installed
* via repl_add_standby must install this so persist_wal_async→repl_broadcast does
* not crash on the fake endpoint. Pattern from test_commit_engine.c, test_p2_integration.c. */
static int ckpt_drop_broadcast(void *ep, wal_catchup_entry_t **entries, int count)
{
(void)ep;
(void)entries;
(void)count;
return 0;
}
extern int (*repl_broadcast_send_hook)(void *ep,
wal_catchup_entry_t **entries,
int count);
/* ------------------------------------------------------------------ */
/* Helpers */
@ -178,6 +196,133 @@ static void test_snapshot_rotation_keeps_snap_keep_n(void)
printf("test_snapshot_rotation_keeps_snap_keep_n: PASS\n");
}
/* ------------------------------------------------------------------ */
/* Helper: check if a WAL segment file at a given start LSN exists. */
/* Builds the name "seg-<lsn16>.wal" inside dir. */
/* ------------------------------------------------------------------ */
static int seg_file_exists(const char* wal_dir, uint64_t seg_start_lsn)
{
char path[4096];
snprintf(path, sizeof(path), "%s/seg-%016" PRIx64 ".wal",
wal_dir, seg_start_lsn);
return access(path, F_OK) == 0 ? 1 : 0;
}
/* ------------------------------------------------------------------ */
/* Test 4: standby cursor-bound trim guard — Req 1.1 (task 3.2, */
/* bug-1147). With a standby whose acked_lsn is below the */
/* active segment, segments the standby still needs for */
/* catch-up are NOT deleted. */
/* */
/* RED proof: revert the repl_trim_lsn floor call in trim_wal_segments */
/* → the segment at the standby's acked LSN is deleted because it's */
/* below the active segment → re-creates the bug-795/828 gap where */
/* catch-up hits a missing segment → permanent committed-job loss. */
/* ------------------------------------------------------------------ */
static void test_trim_guard_preserves_standby_segments(void)
{
char tmpdir[256];
persist_t* p = make_ckpt_e2e(tmpdir, sizeof(tmpdir), 2);
TEST_ASSERT_NOT_NULL(p);
/* Install drop hook so repl_broadcast doesn't crash on the dummy ep */
repl_broadcast_send_hook = ckpt_drop_broadcast;
/* Add a standby with acked_lsn = 2 (simulating a standby that has
* caught up through LSN 2 but not beyond) */
int dummy_ep = 0;
int idx = repl_add_standby(&p->repl, (void*)&dummy_ep, "standby1", 7001);
TEST_ASSERT_TRUE(idx >= 0);
repl_on_ack(&p->repl, (void*)&dummy_ep, 2);
/* Write entries to create segments.
* init: current_lsn = 1 (LSN 0 reserved, fresh store)
* write "x" @ LSN 1 → current_lsn = 2
* force → close seg-at-1, open seg-at-2
* write "y" @ LSN 2 → current_lsn = 3
* force → close seg-at-2, open seg-at-3
*
* Now we have 3 segments: seg-...001.wal, seg-...002.wal, seg-...003.wal.
* Active segment = seg-at-3. Standby acked_lsn = 2. */
TEST_ASSERT_EQUAL_INT(0, persist_wal_async(p, WAL_JOB_UPDATE, "x", 1));
TEST_ASSERT_EQUAL_INT(0, persist_test_force_new_segment(p));
TEST_ASSERT_EQUAL_INT(0, persist_wal_async(p, WAL_JOB_UPDATE, "y", 1));
TEST_ASSERT_EQUAL_INT(0, persist_test_force_new_segment(p));
/* Trigger checkpoint → trim_wal_segments runs */
TEST_ASSERT_EQUAL_INT(0, persist_checkpoint(p));
/* floor = repl_trim_lsn(active_seg_lsn=3, ...) = min(3, acked=2) = 2.
* So seg_start_lsn < 2 means only seg-at-1 is deleted (1 < 2).
* seg-at-2 (the standby still needs it) is NOT deleted (2 >= 2). */
char wal_path[512];
snprintf(wal_path, sizeof(wal_path), "%s/e2e-ckpt/data/wal", tmpdir);
/* The old segment below the standby's acked LSN IS trimmed */
TEST_ASSERT_FALSE_MESSAGE(
seg_file_exists(wal_path, 1),
"seg-at-1: below standby acked_lsn=2, MUST be trimmed");
/* The segment at the standby's acked LSN is PRESERVED (bug-1147 guard) */
TEST_ASSERT_TRUE_MESSAGE(
seg_file_exists(wal_path, 2),
"seg-at-2: at standby acked_lsn=2, MUST be preserved (bug-1147 guard)");
/* The active segment is never trimmed */
TEST_ASSERT_TRUE_MESSAGE(
seg_file_exists(wal_path, 3),
"seg-at-3: active segment, MUST always be preserved");
repl_broadcast_send_hook = NULL;
teardown_ckpt_e2e(p);
printf("test_trim_guard_preserves_standby_segments: PASS\n");
}
/* ------------------------------------------------------------------ */
/* Test 5: trim with no standbys proceeds as before — Req 1.1 */
/* (task 3.2). With no standbys registered, the floor */
/* defaults to active_seg_lsn, so all old segments are */
/* trimmed. This confirms the guard does not prevent normal */
/* cleanup when no standbys need protection. */
/* ------------------------------------------------------------------ */
static void test_trim_without_standbys_proceeds_normally(void)
{
char tmpdir[256];
persist_t* p = make_ckpt_e2e(tmpdir, sizeof(tmpdir), 2);
TEST_ASSERT_NOT_NULL(p);
/* No standbys — just create segments and checkpoint */
TEST_ASSERT_EQUAL_INT(0, persist_wal_async(p, WAL_JOB_UPDATE, "a", 1));
TEST_ASSERT_EQUAL_INT(0, persist_test_force_new_segment(p));
TEST_ASSERT_EQUAL_INT(0, persist_wal_async(p, WAL_JOB_UPDATE, "b", 1));
TEST_ASSERT_EQUAL_INT(0, persist_test_force_new_segment(p));
TEST_ASSERT_EQUAL_INT(0, persist_checkpoint(p));
char wal_path[512];
snprintf(wal_path, sizeof(wal_path), "%s/e2e-ckpt/data/wal", tmpdir);
/* Without standbys, floor = active_seg_lsn = 3.
* seg_at_1 < 3 → deleted. seg_at_2 < 3 → deleted too. */
TEST_ASSERT_FALSE_MESSAGE(
seg_file_exists(wal_path, 1),
"seg-at-1: no standbys, MUST be trimmed");
TEST_ASSERT_FALSE_MESSAGE(
seg_file_exists(wal_path, 2),
"seg-at-2: no standbys, MUST be trimmed");
/* Active segment still there */
TEST_ASSERT_TRUE_MESSAGE(
seg_file_exists(wal_path, 3),
"seg-at-3: active segment, MUST always be preserved");
teardown_ckpt_e2e(p);
printf("test_trim_without_standbys_proceeds_normally: PASS\n");
}
/* ------------------------------------------------------------------ */
/* Suite entry point */
/* ------------------------------------------------------------------ */
@ -189,4 +334,6 @@ void test_e2e_checkpoint(void)
RUN_TEST(test_checkpoint_recovery_lsn_continuity);
RUN_TEST(test_checkpoint_wal_trim_after_checkpoint);
RUN_TEST(test_snapshot_rotation_keeps_snap_keep_n);
RUN_TEST(test_trim_guard_preserves_standby_segments);
RUN_TEST(test_trim_without_standbys_proceeds_normally);
}