Issue#111: mysqld sometimes crashes

Summary:
When get_row_by_rowid() call in ha_rocksdb::secondary_index_read
returns an error, then the error must be returned from
ha_rocksdb::secondary_index_read, too.

Test Plan: mtr

Reviewers: jtolmer, jkedgar, yoshinorim, hermanlee4

Reviewed By: hermanlee4

Subscribers: webscalesql-eng

Differential Revision: https://reviews.facebook.net/D52113

mysql-test/suite/rocksdb/r/issue111.result

@@ -0,0 +1,32 @@
+create table t1 (
+pk int not null primary key, 
+col1 int not null, 
+col2 int not null, 
+key(col1)
+) engine=rocksdb;
+create table ten(a int primary key);
+insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table one_k(a int primary key);
+insert into one_k select A.a + B.a* 10 + C.a * 100 from ten A, ten B, ten C;
+insert into t1 select a,a,a from one_k;
+# Start the transaction, get the snapshot
+begin;
+select * from t1 where col1<10;
+pk	col1	col2
+0	0	0
+1	1	1
+2	2	2
+3	3	3
+4	4	4
+5	5	5
+6	6	6
+7	7	7
+8	8	8
+9	9	9
+# Connect with another connection and make a conflicting change
+begin;
+update t1 set col2=123456 where pk=0;
+commit;
+update t1 set col2=col2+1 where col1 < 10 limit 5;
+ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
+drop table t1, ten, one_k;

mysql-test/suite/rocksdb/t/issue111.test

@@ -0,0 +1,38 @@
+--source include/have_rocksdb.inc
+
+connect (con2,localhost,root,,);
+connection default;
+
+create table t1 (
+  pk int not null primary key, 
+  col1 int not null, 
+  col2 int not null, 
+  key(col1)
+) engine=rocksdb;
+
+create table ten(a int primary key);
+insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table one_k(a int primary key);
+insert into one_k select A.a + B.a* 10 + C.a * 100 from ten A, ten B, ten C;
+
+insert into t1 select a,a,a from one_k;
+
+--echo # Start the transaction, get the snapshot
+begin;
+select * from t1 where col1<10;
+
+--echo # Connect with another connection and make a conflicting change
+connection con2;
+
+begin;
+update t1 set col2=123456 where pk=0;
+commit;
+
+connection default;
+
+--error ER_LOCK_DEADLOCK
+update t1 set col2=col2+1 where col1 < 10 limit 5;
+
+disconnect con2;
+drop table t1, ten, one_k;

storage/rocksdb/ha_rocksdb.cc

@@ -3757,6 +3757,9 @@ int ha_rocksdb::secondary_index_read(int keyno, uchar *buf)
 {
   stats.rows_requested++;
 
+  /* Use STATUS_NOT_FOUND when record not found or some error occurred */
+  table->status= STATUS_NOT_FOUND;
+
   if (scan_it->Valid())
   {
     rocksdb::Slice key= scan_it->key();
@@ -3790,11 +3793,10 @@ int ha_rocksdb::secondary_index_read(int keyno, uchar *buf)
         stats.rows_read++;
         stats.rows_index_next++;
         update_row_stats(table, ROWS_READ);
-        return rc;
       }
+      return rc;
     }
   }
-  table->status= STATUS_NOT_FOUND;
   return HA_ERR_END_OF_FILE;
 }
 
@@ -4193,7 +4195,7 @@ int ha_rocksdb::index_read_map_impl(uchar *buf, const uchar *key,
 
   if (rc)
   {
-    table->status= STATUS_NOT_FOUND; /* Only not found error is possible */
+    table->status= STATUS_NOT_FOUND; /* This status is returned on any error */
     io_perf_end_and_record();
     DBUG_RETURN(rc);
   }
@@ -4634,19 +4636,20 @@ int ha_rocksdb::get_row_by_rowid(uchar *buf, const char *rowid, uint rowid_size)
   }
   found= !s.IsNotFound();
 
+  table->status= STATUS_NOT_FOUND;
   if (found)
   {
     last_rowkey.copy((const char*)rowid, rowid_size, &my_charset_bin);
     rc= convert_record_from_storage_format(&key_slice, buf);
-    table->status= 0;
+    if (!rc)
+      table->status= 0;
   }
   else
   {
     /*
       Note: we don't need to unlock the row. It is intentional that we keep
       locks on rows that don't exist.
     */
-    table->status= STATUS_NOT_FOUND;
     rc= HA_ERR_KEY_NOT_FOUND;
   }