MDEV-32363 Interface to isolate node from the cluster

Author: temeo

wsrep_node_isolation.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2024 Codership Oy <[email protected]>
+ *
+ * This file is part of wsrep-API.
+ *
+ * Wsrep-API is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Wsrep-API is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with wsrep-API.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef WSREP_NODE_ISOLATION_H
+#define WSREP_NODE_ISOLATION_H
+
+/** @file wsrep_node_isolation.h
+ *
+ * This file defines and interface to isolate the node from
+ * the rest of the cluster. The purpose of isolation is to shut
+ * down all communication with the rest of the cluster in case
+ * of node failure where the node cannot continue reliably anymore,
+ * e.g. in case of handling a signal which will terminate the process.
+ */
+
+/**
+ * Mode of node isolation.
+ */
+enum wsrep_node_isolation_mode
+{
+    /** Node is not isolated. */
+    WSREP_NODE_ISOLATION_NOT_ISOLATED,
+    /** Node is isolated from the rest of the cluster on network
+     * level. All ongoing network connections will be terminated and
+     * no new connections are accepted. */
+    WSREP_NODE_ISOLATION_ISOLATED,
+    /** As WSREP_NODE_ISOLATION_ON, but also force the provider
+     * to deliver view with status WSREP_VIEW_DISCONNECTED. */
+    WSREP_NODE_ISOLATION_FORCE_DISCONNECT,
+};
+
+enum wsrep_node_isolation_result
+{
+    /** Setting the isolation mode was successful. */
+    WSREP_NODE_ISOLATION_SUCCESS,
+    /** Invalid isolation mode was passed. */
+    WSREP_NODE_ISOLATION_INVALID_VALUE
+};
+
+/** Set mode isolation mode according to give wsrep_node_isolation_mode
+ * enum.
+ *
+ * The implementation must be async signal safe to allow calling
+ * it from program signal handler.
+ *
+ * @param mode Mode to set.
+ * @return wsrep_node_isolation_result enum.
+ */
+typedef enum wsrep_node_isolation_result (*wsrep_node_isolation_mode_set_fn_v1)(
+    enum wsrep_node_isolation_mode mode);
+
+#define WSREP_NODE_ISOLATION_MODE_SET_V1 "wsrep_node_isolation_mode_set_v1"
+
+#endif /* WSREP_NODE_ISOLATION_H */