Rev 321: a better way to resend calls after recovery in http://samba.org/~tridge/ctdb

[tridge at samba.org]

------------------------------------------------------------
revno: 321
revision-id: tridge at samba.org-20070518145649-ftagi1x44wuzm36n
parent: tridge at samba.org-20070518134829-y384ldoxc07qxxi5
committer: Andrew Tridgell <tridge at samba.org>
branch nick: tridge
timestamp: Sat 2007-05-19 00:56:49 +1000
message:
  a better way to resend calls after recovery
modified:
  common/ctdb_call.c             ctdb_call.c-20061128065342-to93h6eejj5kon81-1
  common/ctdb_freeze.c           ctdb_freeze.c-20070512051503-935zdtyuqknqnhmo-1
  include/ctdb_private.h         ctdb_private.h-20061117234101-o3qt14umlg9en8z0-13
=== modified file 'common/ctdb_call.c'
--- a/common/ctdb_call.c	2007-05-18 13:23:36 +0000
+++ b/common/ctdb_call.c	2007-05-18 14:56:49 +0000
@@ -607,37 +607,20 @@
 */
 static int ctdb_call_destructor(struct ctdb_call_state *state)
 {
+	DLIST_REMOVE(state->ctdb_db->ctdb->pending_calls, state);
 	ctdb_reqid_remove(state->ctdb_db->ctdb, state->reqid);
 	return 0;
 }
 
 
 /*
-  called when a ctdb_call times out
+  called when a ctdb_call needs to be resent after a reconfigure event
 */
-static void ctdb_call_timeout(struct event_context *ev, struct timed_event *te, 
-			      struct timeval t, void *private_data)
+static void ctdb_call_resend(struct ctdb_call_state *state)
 {
-	struct ctdb_call_state *state = talloc_get_type(private_data, struct ctdb_call_state);
 	struct ctdb_context *ctdb = state->ctdb_db->ctdb;
 
-	ctdb->status.timeouts.call++;
-
-	event_add_timed(ctdb->ev, state, timeval_current_ofs(CTDB_CALL_TIMEOUT, 0), 
-			ctdb_call_timeout, state);
-
-	if (++state->resend_count < 10 &&
-	    (ctdb->vnn_map->generation == state->generation ||
-	     ctdb->recovery_mode != CTDB_RECOVERY_NORMAL)) {
-		/* the call is just being slow, or we are curently
-		   recovering, give it more time */
-		return;
-	}
-
-	/* the generation count changed or we're timing out too much -
-	   the call must be re-issued */
 	state->generation = ctdb->vnn_map->generation;
-	state->resend_count = 0;
 
 	/* use a new reqid, in case the old reply does eventually come in */
 	ctdb_reqid_remove(ctdb, state->reqid);
@@ -651,7 +634,19 @@
 	state->c->hdr.destnode = ctdb->vnn;
 
 	ctdb_queue_packet(ctdb, &state->c->hdr);
-	DEBUG(0,("requeued ctdb_call after timeout\n"));
+	DEBUG(0,("resent ctdb_call\n"));
+}
+
+/*
+  resend all pending calls on recovery
+ */
+void ctdb_call_resend_all(struct ctdb_context *ctdb)
+{
+	struct ctdb_call_state *state, *next;
+	for (state=ctdb->pending_calls;state;state=next) {
+		next = state->next;
+		ctdb_call_resend(state);
+	}
 }
 
 /*
@@ -743,10 +738,10 @@
 	state->state  = CTDB_CALL_WAIT;
 	state->generation = ctdb->vnn_map->generation;
 
+	DLIST_ADD(ctdb->pending_calls, state);
+
 	ctdb_queue_packet(ctdb, &state->c->hdr);
 
-	event_add_timed(ctdb->ev, state, timeval_current_ofs(CTDB_CALL_TIMEOUT, 0), 
-			ctdb_call_timeout, state);
 	return state;
 }
 

=== modified file 'common/ctdb_freeze.c'
--- a/common/ctdb_freeze.c	2007-05-12 11:25:26 +0000
+++ b/common/ctdb_freeze.c	2007-05-18 14:56:49 +0000
@@ -223,5 +223,6 @@
 {
 	talloc_free(ctdb->freeze_handle);
 	ctdb->freeze_handle = NULL;
+	ctdb_call_resend_all(ctdb);
 	return 0;
 }

=== modified file 'include/ctdb_private.h'
--- a/include/ctdb_private.h	2007-05-18 13:48:29 +0000
+++ b/include/ctdb_private.h	2007-05-18 14:56:49 +0000
@@ -265,6 +265,7 @@
 	uint32_t num_clients;
 	uint32_t seqnum_frequency;
 	uint32_t recovery_master;
+	struct ctdb_call_state *pending_calls;
 };
 
 struct ctdb_db_context {
@@ -300,11 +301,6 @@
           ctdb_fatal(ctdb, "Out of memory in " __location__ ); \
 	  }} while (0)
 
-/* timeout for ctdb call operations. When this timeout expires we
-   check if the generation count has changed, and if it has then
-   re-issue the call */
-#define CTDB_CALL_TIMEOUT 2
-
 /* maximum timeout for ctdb control calls */
 #define CTDB_CONTROL_TIMEOUT 60
 
@@ -390,6 +386,7 @@
   state of a in-progress ctdb call
 */
 struct ctdb_call_state {
+	struct ctdb_call_state *next, *prev;
 	enum call_state state;
 	uint32_t reqid;
 	struct ctdb_req_call *c;
@@ -397,7 +394,6 @@
 	const char *errmsg;
 	struct ctdb_call call;
 	uint32_t generation;
-	uint32_t resend_count;
 	struct {
 		void (*fn)(struct ctdb_call_state *);
 		void *private_data;
@@ -828,5 +824,6 @@
 void ctdb_send_keepalive(struct ctdb_context *ctdb, uint32_t destnode);
 
 void ctdb_daemon_cancel_controls(struct ctdb_context *ctdb, struct ctdb_node *node);
+void ctdb_call_resend_all(struct ctdb_context *ctdb);
 
 #endif