Merge pull request #2244 from wiredtiger/WT-2149

WT-2149 Track if the lookaside table is open when starting eviction workers

7 files changed, 53 insertions, 33 deletions

diff --git a/dist/flags.py b/dist/flags.py
index d98f249335e..65b68cf4277 100644
--- a/dist/flags.py
+++ b/dist/flags.py
@@ -92,6 +92,7 @@ flags = {
         'CONN_CKPT_SYNC',
         'CONN_CLOSING',
         'CONN_EVICTION_RUN',
+        'CONN_LAS_OPEN',
         'CONN_LEAK_MEMORY',
         'CONN_LOG_SERVER_RUN',
         'CONN_LSM_MERGE',
diff --git a/src/cache/cache_las.c b/src/cache/cache_las.c
index 30de8ce2301..2eb406c2af8 100644
--- a/src/cache/cache_las.c
+++ b/src/cache/cache_las.c
@@ -25,11 +25,8 @@ __wt_las_stats_update(WT_SESSION_IMPL *session)
 	 * Lookaside table statistics are copied from the underlying lookaside
 	 * table data-source statistics. If there's no lookaside table, values
 	 * remain 0.
-	 *
-	 * The statistics log is started before we create the lookaside table,
-	 * check the session and the cursor for validity.
 	 */
-	if (conn->las_session == NULL || conn->las_session->las_cursor == NULL)
+	if (!F_ISSET(conn, WT_CONN_LAS_OPEN))
 		return;
 
 	/*
@@ -62,25 +59,28 @@ __wt_las_create(WT_SESSION_IMPL *session)
 
 	/*
 	 * Done at startup: we cannot do it on demand because we require the
-	 * schema lock to create and drop the file, and it may not always be
+	 * schema lock to create and drop the table, and it may not always be
 	 * available.
 	 *
-	 * Discard any previous incarnation of the file.
+	 * Discard any previous incarnation of the table.
 	 */
 	WT_RET(__wt_session_drop(session, WT_LAS_URI, drop_cfg));
 
-	/* Re-create the file. */
+	/* Re-create the table. */
 	WT_RET(__wt_session_create(session, WT_LAS_URI, WT_LAS_FORMAT));
 
 	/*
-	 * Open an internal session, used for the shared lookaside cursor.
-	 *
-	 * Sessions associated with a lookaside cursor should never be tapped
-	 * for eviction.
+	 * Open a shared internal session used to access the lookaside table.
+	 * This session should never be tapped for eviction.
 	 */
 	session_flags = WT_SESSION_LOOKASIDE_CURSOR | WT_SESSION_NO_EVICTION;
-	return (__wt_open_internal_session(
+	WT_RET(__wt_open_internal_session(
 	    conn, "lookaside table", true, session_flags, &conn->las_session));
+
+	/* Flag that the lookaside table has been created. */
+	F_SET(conn, WT_CONN_LAS_OPEN);
+
+	return (0);
 }
 
 /*
diff --git a/src/conn/conn_open.c b/src/conn/conn_open.c
index 6db0c4bb10c..04815c8e152 100644
--- a/src/conn/conn_open.c
+++ b/src/conn/conn_open.c
@@ -234,7 +234,13 @@ __wt_connection_workers(WT_SESSION_IMPL *session, const char *cfg[])
 	WT_RET(__wt_statlog_create(session, cfg));
 	WT_RET(__wt_logmgr_create(session, cfg));
 
-	/* Run recovery. */
+	/*
+	 * Run recovery.
+	 * NOTE: This call will start (and stop) eviction if recovery is
+	 * required.  Recovery must run before the lookaside table is created
+	 * (because recovery will update the metadata), and before eviction is
+	 * started for real.
+	 */
 	WT_RET(__wt_txn_recover(session));
 
 	/*
@@ -249,8 +255,11 @@ __wt_connection_workers(WT_SESSION_IMPL *session, const char *cfg[])
 	/* Create the lookaside table. */
 	WT_RET(__wt_las_create(session));
 
-	/* Start eviction threads. */
-	WT_RET(__wt_evict_create(session, true));
+	/*
+	 * Start eviction threads.
+	 * NOTE: Eviction must be started after the lookaside table is created.
+	 */
+	WT_RET(__wt_evict_create(session));
 
 	/* Start the handle sweep thread. */
 	WT_RET(__wt_sweep_create(session));
diff --git a/src/evict/evict_lru.c b/src/evict/evict_lru.c
index dd1c86b5ad8..f9171900ca4 100644
--- a/src/evict/evict_lru.c
+++ b/src/evict/evict_lru.c
@@ -251,12 +251,17 @@ __evict_workers_resize(WT_SESSION_IMPL *session)
 	for (i = conn->evict_workers_alloc; i < conn->evict_workers_max; i++) {
 		/*
 		 * Eviction worker threads get their own session.
-		 * Eviction worker threads get their own lookaside table cursor.
 		 * Eviction worker threads may be called upon to perform slow
 		 * operations for the block manager.
+		 *
+		 * Eviction worker threads get their own lookaside table cursor
+		 * if the lookaside table is open.  Note that eviction is also
+		 * started during recovery, before the lookaside table is
+		 * created.
 		 */
-		session_flags =
-		    WT_SESSION_CAN_WAIT | WT_SESSION_LOOKASIDE_CURSOR;
+		session_flags = WT_SESSION_CAN_WAIT;
+		if (F_ISSET(conn, WT_CONN_LAS_OPEN))
+			FLD_SET(session_flags, WT_SESSION_LOOKASIDE_CURSOR);
 		WT_ERR(__wt_open_internal_session(conn, "eviction-worker",
 		    false, session_flags, &workers[i].session));
 		workers[i].id = i;
@@ -278,7 +283,7 @@ err:	conn->evict_workers_alloc = conn->evict_workers_max;
  *	Start the eviction server thread.
  */
 int
-__wt_evict_create(WT_SESSION_IMPL *session, bool with_las)
+__wt_evict_create(WT_SESSION_IMPL *session)
 {
 	WT_CONNECTION_IMPL *conn;
 	uint32_t session_flags;
@@ -297,7 +302,8 @@ __wt_evict_create(WT_SESSION_IMPL *session, bool with_las)
 	 * perform slow operations for the block manager.  (The flag is not
 	 * reset if reconfigured later, but I doubt that's a problem.)
 	 */
-	session_flags = with_las ? WT_SESSION_LOOKASIDE_CURSOR : 0;
+	session_flags = F_ISSET(conn, WT_CONN_LAS_OPEN) ?
+	    WT_SESSION_LOOKASIDE_CURSOR : 0;
 	if (conn->evict_workers_max == 0)
 		FLD_SET(session_flags, WT_SESSION_CAN_WAIT);
 	WT_RET(__wt_open_internal_session(conn,
diff --git a/src/include/extern.h b/src/include/extern.h
index 171f6b02768..1f63f07646e 100644
--- a/src/include/extern.h
+++ b/src/include/extern.h
@@ -319,7 +319,7 @@ extern int __wt_curtable_open(WT_SESSION_IMPL *session, const char *uri, const c
 extern int __wt_evict_file(WT_SESSION_IMPL *session, int syncop);
 extern void __wt_evict_list_clear_page(WT_SESSION_IMPL *session, WT_REF *ref);
 extern int __wt_evict_server_wake(WT_SESSION_IMPL *session);
-extern int __wt_evict_create(WT_SESSION_IMPL *session, bool with_las);
+extern int __wt_evict_create(WT_SESSION_IMPL *session);
 extern int __wt_evict_destroy(WT_SESSION_IMPL *session);
 extern int __wt_evict_file_exclusive_on(WT_SESSION_IMPL *session, bool *evict_resetp);
 extern void __wt_evict_file_exclusive_off(WT_SESSION_IMPL *session);
diff --git a/src/include/flags.h b/src/include/flags.h
index ca3c3c38245..24dccd30913 100644
--- a/src/include/flags.h
+++ b/src/include/flags.h
@@ -6,17 +6,18 @@
 #define	WT_CONN_CKPT_SYNC				0x00000002
 #define	WT_CONN_CLOSING					0x00000004
 #define	WT_CONN_EVICTION_RUN				0x00000008
-#define	WT_CONN_LEAK_MEMORY				0x00000010
-#define	WT_CONN_LOG_SERVER_RUN				0x00000020
-#define	WT_CONN_LSM_MERGE				0x00000040
-#define	WT_CONN_PANIC					0x00000080
-#define	WT_CONN_SERVER_ASYNC				0x00000100
-#define	WT_CONN_SERVER_CHECKPOINT			0x00000200
-#define	WT_CONN_SERVER_LSM				0x00000400
-#define	WT_CONN_SERVER_RUN				0x00000800
-#define	WT_CONN_SERVER_STATISTICS			0x00001000
-#define	WT_CONN_SERVER_SWEEP				0x00002000
-#define	WT_CONN_WAS_BACKUP				0x00004000
+#define	WT_CONN_LAS_OPEN				0x00000010
+#define	WT_CONN_LEAK_MEMORY				0x00000020
+#define	WT_CONN_LOG_SERVER_RUN				0x00000040
+#define	WT_CONN_LSM_MERGE				0x00000080
+#define	WT_CONN_PANIC					0x00000100
+#define	WT_CONN_SERVER_ASYNC				0x00000200
+#define	WT_CONN_SERVER_CHECKPOINT			0x00000400
+#define	WT_CONN_SERVER_LSM				0x00000800
+#define	WT_CONN_SERVER_RUN				0x00001000
+#define	WT_CONN_SERVER_STATISTICS			0x00002000
+#define	WT_CONN_SERVER_SWEEP				0x00004000
+#define	WT_CONN_WAS_BACKUP				0x00008000
 #define	WT_EVICTING					0x00000001
 #define	WT_EVICT_LOOKASIDE				0x00000002
 #define	WT_EVICT_UPDATE_RESTORE				0x00000004
diff --git a/src/txn/txn_recover.c b/src/txn/txn_recover.c
index 9d8a19cbff3..63d86969311 100644
--- a/src/txn/txn_recover.c
+++ b/src/txn/txn_recover.c
@@ -501,7 +501,7 @@ __wt_txn_recover(WT_SESSION_IMPL *session)
 	 * regular eviction to manage paging.  Start eviction threads for
 	 * recovery without LAS cursors.
 	 */
-	WT_ERR(__wt_evict_create(session, false));
+	WT_ERR(__wt_evict_create(session));
 	eviction_started = true;
 
 	/*
@@ -533,6 +533,9 @@ done:	FLD_SET(conn->log_flags, WT_CONN_LOG_RECOVER_DONE);
 err:	WT_TRET(__recovery_free(&r));
 	__wt_free(session, config);
 
+	if (ret != 0)
+		__wt_err(session, ret, "Recovery failed");
+
 	/*
 	 * Destroy the eviction threads that were started in support of
 	 * recovery.  They will be restarted once the lookaside table is