[PATCH] vinyl: fix index build not working after recovery

[PATCH] vinyl: fix index build not working after recovery

[Vladimir Davydov]

While building a secondary index for a Vinyl space, we use xm->lsn to
skip statements inserted after build began (as those statements are
propagated by the on_replace trigger callback anyway). The xm->lsn is
advanced every time we insert something into a Vinyl space. The problem
is during recovery we skip statements that have been dumped to disk so
xm->lsn may lag behind the instance vclock once recovery is complete.
In this case if we try to create a new Vinyl index right after recovery
completion, before any DML operation is executed on a Vinyl space, we
will skip statements that would otherwise get into the new index.

Fix this issue by resetting xm->lsn to the instance vclock upon recovery
completion.

Closes #3903
---
https://github.com/tarantool/tarantool/issues/3903
https://github.com/tarantool/tarantool/commits/dv/gh-3903-vy-fix-index-build-after-recovery

 src/box/vinyl.c          | 13 ++++++++++++-
 test/engine/ddl.result   | 18 ++++++++++++++++++
 test/engine/ddl.test.lua |  7 +++++++
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/box/vinyl.c b/src/box/vinyl.c
index f5b36ce1..ca987134 100644
--- a/src/box/vinyl.c
+++ b/src/box/vinyl.c
@@ -2725,7 +2725,6 @@ vinyl_engine_begin_initial_recovery(struct engine *engine,
 	struct vy_env *e = vy_env(engine);
 	assert(e->status == VINYL_OFFLINE);
 	if (recovery_vclock != NULL) {
-		e->xm->lsn = vclock_sum(recovery_vclock);
 		e->recovery_vclock = recovery_vclock;
 		e->recovery = vy_log_begin_recovery(recovery_vclock);
 		if (e->recovery == NULL)
@@ -2787,6 +2786,18 @@ vinyl_engine_end_recovery(struct engine *engine)
 		vy_gc(e, e->recovery, VY_GC_INCOMPLETE, INT64_MAX);
 		vy_recovery_delete(e->recovery);
 		e->recovery = NULL;
+		/*
+		 * During recovery we skip statements that have
+		 * been dumped to disk - see vy_is_committed() -
+		 * so it may turn out that tx_manager::lsn stays
+		 * behind the instance vclock while we need it
+		 * to be up-to-date once recovery is complete,
+		 * because we use it while building an index to
+		 * skip statements inserted after build began -
+		 * see vinyl_space_build_index() - so we reset
+		 * it upon recovery completion.
+		 */
+		e->xm->lsn = vclock_sum(e->recovery_vclock);
 		e->recovery_vclock = NULL;
 		vy_env_complete_recovery(e);
 		break;
diff --git a/test/engine/ddl.result b/test/engine/ddl.result
index 3c84e942..e3cff7f4 100644
--- a/test/engine/ddl.result
+++ b/test/engine/ddl.result
@@ -2114,6 +2114,24 @@ s.index.i3:select()
   - [4, 'zzz', 'ddd', -666]
   - [1, 'zzz', 'aaa', 999, 'fff']
 ...
+--
+-- gh-3903: index build doesn't work after recovery.
+--
+s.index.i1:drop()
+---
+...
+_ = s:create_index('i1', {parts = {2, 'string'}, unique = false})
+---
+...
+s.index.i1:select()
+---
+- - [3, 'xxx', null, 777, 'ggg']
+  - [5, 'xxx', 'eee', 555, 'hhh']
+  - [2, 'yyy', 'bbb', -888]
+  - [6, 'yyy', null, -444]
+  - [1, 'zzz', 'aaa', 999, 'fff']
+  - [4, 'zzz', 'ddd', -666]
+...
 box.snapshot()
 ---
 - ok
diff --git a/test/engine/ddl.test.lua b/test/engine/ddl.test.lua
index 563a20fa..cdaf7a5b 100644
--- a/test/engine/ddl.test.lua
+++ b/test/engine/ddl.test.lua
@@ -765,6 +765,13 @@ s.index.i1:select()
 s.index.i2:select()
 s.index.i3:select()
 
+--
+-- gh-3903: index build doesn't work after recovery.
+--
+s.index.i1:drop()
+_ = s:create_index('i1', {parts = {2, 'string'}, unique = false})
+s.index.i1:select()
+
 box.snapshot()
 
 s:drop()
-- 
2.11.0

Re: [PATCH] vinyl: fix index build not working after recovery

[Vladimir Davydov]

Pushed to 2.1 and 1.10.