diff --git a/servers/slapd/back-mdb/back-mdb.h b/servers/slapd/back-mdb/back-mdb.h
index 98058e92f4..0646308eab 100644
--- a/servers/slapd/back-mdb/back-mdb.h
+++ b/servers/slapd/back-mdb/back-mdb.h
@@ -33,7 +33,8 @@ LDAP_BEGIN_DECL
 #define MDB_DN2ID		1
 #define MDB_ID2ENTRY	2
 #define MDB_ID2VAL		3
-#define MDB_NDB			4
+#define MDB_IDXCKP		4
+#define MDB_NDB			5
 
 /* The default search IDL stack cache depth */
 #define DEFAULT_SEARCH_STACK_DEPTH	16
@@ -122,6 +123,7 @@ struct mdb_info {
 #define mi_dn2id	mi_dbis[MDB_DN2ID]
 #define mi_ad2id	mi_dbis[MDB_AD2ID]
 #define mi_id2val	mi_dbis[MDB_ID2VAL]
+#define mi_idxckp	mi_dbis[MDB_IDXCKP]
 
 typedef struct mdb_op_info {
 	OpExtra		moi_oe;
diff --git a/servers/slapd/back-mdb/config.c b/servers/slapd/back-mdb/config.c
index 54fed1383f..c0c4b4013c 100644
--- a/servers/slapd/back-mdb/config.c
+++ b/servers/slapd/back-mdb/config.c
@@ -210,23 +210,52 @@ mdb_online_index( void *ctx, void *arg )
 	ID id;
 	Entry *e;
 	int rc, getnext = 1;
-	int i;
+	int i, first = 1;
+	int intr = 0;
 
 	connection_fake_init( &conn, &opbuf, ctx );
 	op = &opbuf.ob_op;
 
 	op->o_bd = be;
 
-	id = 1;
 	key.mv_size = sizeof(ID);
 
 	while ( 1 ) {
-		if ( slapd_shutdown )
-			break;
-
 		rc = mdb_txn_begin( mdb->mi_dbenv, NULL, 0, &txn );
 		if ( rc )
 			break;
+
+		/* pick up where we left off */
+		if ( first ) {
+			MDB_val k0;
+			unsigned short s = 0;
+
+			first = 0;
+			k0.mv_size = sizeof(s);
+			k0.mv_data = &s;
+			rc = mdb_get( txn, mdb->mi_idxckp, &k0, &data );
+			if ( rc ) {
+				mdb_txn_abort( txn );
+				break;
+			}
+			memcpy( &id, data.mv_data, sizeof( id ));
+		}
+
+		/* Save our stopping point */
+		if ( slapd_shutdown || ldap_pvt_thread_pool_pausequery( &connection_pool )) {
+			MDB_val k0;
+			unsigned short s = 0;
+
+			k0.mv_size = sizeof(s);
+			k0.mv_data = &s;
+			data.mv_data = &id;
+			data.mv_size = sizeof( id );
+			mdb_put( txn, mdb->mi_idxckp, &k0, &data, 0 );
+			mdb_txn_commit( txn );
+			intr = 1;
+			break;
+		}
+
 		rc = mdb_cursor_open( txn, mdb->mi_id2entry, &curs );
 		if ( rc ) {
 			mdb_txn_abort( txn );
@@ -276,25 +305,137 @@ mdb_online_index( void *ctx, void *arg )
 		getnext = 1;
 	}
 
-	for ( i = 0; i < mdb->mi_nattrs; i++ ) {
-		if ( mdb->mi_attrs[ i ]->ai_indexmask & MDB_INDEX_DELETING
-			|| mdb->mi_attrs[ i ]->ai_newmask == 0 )
-		{
-			continue;
+	/* all done */
+	if ( !intr ) {
+		for ( i = 0; i < mdb->mi_nattrs; i++ ) {
+			if ( mdb->mi_attrs[ i ]->ai_indexmask & MDB_INDEX_DELETING
+				|| mdb->mi_attrs[ i ]->ai_newmask == 0 )
+			{
+				continue;
+			}
+			mdb->mi_attrs[ i ]->ai_indexmask = mdb->mi_attrs[ i ]->ai_newmask;
+			mdb->mi_attrs[ i ]->ai_newmask = 0;
+		}
+		/* zero out checkpoint DB */
+		rc = mdb_txn_begin( mdb->mi_dbenv, NULL, 0, &txn );
+		if ( !rc ) {
+			mdb_drop( txn, mdb->mi_idxckp, 0 );
+			mdb_txn_commit( txn );
 		}
-		mdb->mi_attrs[ i ]->ai_indexmask = mdb->mi_attrs[ i ]->ai_newmask;
-		mdb->mi_attrs[ i ]->ai_newmask = 0;
 	}
 
 	ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
-	ldap_pvt_runqueue_stoptask( &slapd_rq, rtask );
-	mdb->mi_index_task = NULL;
-	ldap_pvt_runqueue_remove( &slapd_rq, rtask );
+	if ( ldap_pvt_runqueue_isrunning( &slapd_rq, rtask ))
+		ldap_pvt_runqueue_stoptask( &slapd_rq, rtask );
+	if ( intr && !slapd_shutdown ) {
+		/* on pause, resched to run again immediately */
+		time_t t = rtask->interval.tv_sec;
+		rtask->interval.tv_sec = 0;
+		ldap_pvt_runqueue_resched( &slapd_rq, rtask, 0 );
+		rtask->interval.tv_sec = t;
+	} else if ( mdb->mi_index_task ) {
+		mdb->mi_index_task = NULL;
+		ldap_pvt_runqueue_remove( &slapd_rq, rtask );
+	}
 	ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
 
 	return NULL;
 }
 
+static int
+mdb_setup_indexer( struct mdb_info *mdb )
+{
+	MDB_txn *txn;
+	MDB_cursor *curs;
+	MDB_val key, data;
+	int i, rc;
+	unsigned short s;
+
+	rc = mdb_txn_begin( mdb->mi_dbenv, NULL, 0, &txn );
+	if ( rc )
+		return rc;
+	rc = mdb_cursor_open( txn, mdb->mi_idxckp, &curs );
+	if ( rc ) {
+		mdb_txn_abort( txn );
+		return rc;
+	}
+
+	key.mv_size = sizeof( s );
+	key.mv_data = &s;
+
+	/* set indexer task to start at first entry */
+	{
+		ID id = 0;
+		s = 0;			/* key 0 records next entryID to index */
+		data.mv_size = sizeof( ID );
+		data.mv_data = &id;
+		rc = mdb_cursor_put( curs, &key, &data, 0 );
+		if ( rc )
+			goto done;
+	}
+
+	/* record current and new index masks for all new index definitions */
+	{
+		slap_mask_t mask[2];
+		data.mv_size = sizeof(mask);
+		data.mv_data = mask;
+
+		for ( i = 0; i < mdb->mi_nattrs; i++ ) {
+			if ( !mdb->mi_attrs[i]->ai_newmask ) continue;
+			s = mdb->mi_adxs[ mdb->mi_attrs[i]->ai_desc->ad_index ];
+			mask[0] = mdb->mi_attrs[i]->ai_indexmask;
+			mask[1] = mdb->mi_attrs[i]->ai_newmask;
+			rc = mdb_cursor_put( curs, &key, &data, 0 );
+			if ( rc )
+				goto done;
+		}
+	}
+done:
+	mdb_cursor_close( curs );
+	if ( !rc )
+		mdb_txn_commit( txn );
+	else
+		mdb_txn_abort( txn );
+	return rc;
+}
+
+void
+mdb_resume_index( BackendDB *be, MDB_txn *txn )
+{
+	struct mdb_info *mdb = be->be_private;
+	MDB_cursor *curs;
+	MDB_val key, data;
+	int i, rc;
+	unsigned short *s;
+	slap_mask_t *mask;
+	AttributeDescription *ad;
+
+	rc = mdb_cursor_open( txn, mdb->mi_idxckp, &curs );
+	if ( rc )
+		return;
+
+	while(( rc = mdb_cursor_get( curs, &key, &data, MDB_NEXT )) == 0) {
+		s = key.mv_data;
+		if ( !*s )
+			continue;
+		ad = mdb->mi_ads[*s];
+		for ( i=0; i<mdb->mi_nattrs; i++) {
+			if (mdb->mi_attrs[i]->ai_desc == ad ) {
+				mask = data.mv_data;
+				mdb->mi_attrs[i]->ai_indexmask = mask[0];
+				mdb->mi_attrs[i]->ai_newmask = mask[1];
+				break;
+			}
+		}
+	}
+	mdb_cursor_close( curs );
+	ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
+	mdb->mi_index_task = ldap_pvt_runqueue_insert( &slapd_rq, 36000,
+		mdb_online_index, be,
+		LDAP_XSTRING(mdb_online_index), be->be_suffix[0].bv_val );
+	ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
+}
+
 /* Cleanup loose ends after Modify completes */
 static int
 mdb_cf_cleanup( ConfigArgs *c )
@@ -328,6 +469,7 @@ mdb_cf_cleanup( ConfigArgs *c )
 		rc = mdb_attr_dbs_open( c->be, NULL, &c->reply );
 		if ( rc )
 			rc = LDAP_OTHER;
+		mdb_setup_indexer( mdb );
 	}
 	return rc;
 }
diff --git a/servers/slapd/back-mdb/init.c b/servers/slapd/back-mdb/init.c
index 1b6ac18847..16e51bfe5b 100644
--- a/servers/slapd/back-mdb/init.c
+++ b/servers/slapd/back-mdb/init.c
@@ -32,6 +32,7 @@ static const struct berval mdmi_databases[] = {
 	BER_BVC("dn2i"),
 	BER_BVC("id2e"),
 	BER_BVC("id2v"),
+	BER_BVC("ixck"),
 	BER_BVNULL
 };
 
@@ -286,6 +287,13 @@ mdb_db_open( BackendDB *be, ConfigReply *cr )
 		}
 	}
 
+	if ( slapMode & SLAP_SERVER_MODE ) {
+		MDB_stat st;
+		rc = mdb_stat( txn, mdb->mi_idxckp, &st );
+		if ( st.ms_entries )
+			mdb_resume_index( be, txn );
+	}
+
 	rc = mdb_txn_commit(txn);
 	if ( rc != 0 ) {
 		Debug( LDAP_DEBUG_ANY,
@@ -321,11 +329,21 @@ mdb_db_close( BackendDB *be, ConfigReply *cr )
 
 	mdb->mi_flags &= ~MDB_IS_OPEN;
 
-	if( mdb->mi_dbenv ) {
-		mdb_reader_flush( mdb->mi_dbenv );
+	/* remove indexer task */
+	if ( mdb->mi_index_task ) {
+		struct re_s *re = mdb->mi_index_task;
+		ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
+		mdb->mi_index_task = NULL;
+		/* can never actually be running at this point, but paranoia */
+		if ( ldap_pvt_runqueue_isrunning( &slapd_rq, re ) )
+			ldap_pvt_runqueue_stoptask( &slapd_rq, re );
+		ldap_pvt_runqueue_remove( &slapd_rq, re );
+		ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
 	}
 
 	if ( mdb->mi_dbenv ) {
+		mdb_reader_flush( mdb->mi_dbenv );
+
 		if ( mdb->mi_dbis[0] ) {
 			int i;
 
diff --git a/servers/slapd/back-mdb/proto-mdb.h b/servers/slapd/back-mdb/proto-mdb.h
index 6134ef8336..4cb6c47861 100644
--- a/servers/slapd/back-mdb/proto-mdb.h
+++ b/servers/slapd/back-mdb/proto-mdb.h
@@ -64,6 +64,7 @@ void mdb_ad_unwind( struct mdb_info *mdb, int prev_ads );
  */
 
 int mdb_back_init_cf( BackendInfo *bi );
+void mdb_resume_index( BackendDB *be, MDB_txn *txn );
 
 /*
  * dn2entry.c