[SCM] CTDB repository - branch master updated - ctdb-2.1-33-g11734be

Amitay Isaacs amitay at samba.org
Tue Mar 5 23:38:07 MST 2013


The branch, master has been updated
       via  11734be353a1e246163eda631d35dfe55d1d6fb1 (commit)
       via  3e09f25d419635f6dd679b48fa65370f7860be7d (commit)
      from  5402f85dde045576cbaf64e01c68e28ed52204e8 (commit)

http://gitweb.samba.org/?p=ctdb.git;a=shortlog;h=master


- Log -----------------------------------------------------------------
commit 11734be353a1e246163eda631d35dfe55d1d6fb1
Author: Amitay Isaacs <amitay at gmail.com>
Date:   Fri Feb 22 12:59:39 2013 +1100

    common/io: For scheduling immediate events use tevent_schedule_immediate
    
    tevent_schedule_immediate() is much more efficient at handling events that need
    to be processed immediately rather than creating timed events with
    timeval_zero().
    
    Signed-off-by: Amitay Isaacs <amitay at gmail.com>

commit 3e09f25d419635f6dd679b48fa65370f7860be7d
Author: Amitay Isaacs <amitay at gmail.com>
Date:   Thu Feb 21 13:16:15 2013 +1100

    ctdbd: Add an index db for message list for faster searches
    
    When CTDB is busy with lots of smbd, CTDB was spending too much time in
    daemon_check_srvids() which searches a list of srvids in the registered
    message handlers.  Using a hash based index significantly improves the
    performance of search in a linked list.
    
    Signed-off-by: Amitay Isaacs <amitay at gmail.com>

-----------------------------------------------------------------------

Summary of changes:
 common/ctdb_io.c       |   26 ++++---
 common/ctdb_message.c  |  205 +++++++++++++++++++++++++++++++++++++++++++++---
 include/ctdb_private.h |   13 +++-
 server/ctdb_daemon.c   |    8 +--
 4 files changed, 218 insertions(+), 34 deletions(-)


Changeset truncated at 500 lines:

diff --git a/common/ctdb_io.c b/common/ctdb_io.c
index b4224c4..4e592b9 100644
--- a/common/ctdb_io.c
+++ b/common/ctdb_io.c
@@ -45,6 +45,7 @@ struct ctdb_queue_pkt {
 
 struct ctdb_queue {
 	struct ctdb_context *ctdb;
+	struct tevent_immediate *im;
 	struct ctdb_buffer buffer; /* input buffer */
 	struct ctdb_queue_pkt *out_queue, *out_queue_tail;
 	uint32_t out_queue_length;
@@ -66,8 +67,8 @@ int ctdb_queue_length(struct ctdb_queue *queue)
 
 static void queue_process(struct ctdb_queue *queue);
 
-static void queue_process_event(struct event_context *ev, struct timed_event *te,
-				struct timeval t, void *private_data)
+static void queue_process_event(struct tevent_context *ev, struct tevent_immediate *im,
+				void *private_data)
 {
 	struct ctdb_queue *queue = talloc_get_type(private_data, struct ctdb_queue);
 
@@ -118,9 +119,9 @@ static void queue_process(struct ctdb_queue *queue)
 	queue->buffer.length -= pkt_size;
 
 	if (queue->buffer.length > 0) {
-		/* There is more data to be processed, setup timed event */
-		event_add_timed(queue->ctdb->ev, queue, timeval_zero(),
-				queue_process_event, queue);
+		/* There is more data to be processed, schedule an event */
+		tevent_schedule_immediate(queue->im, queue->ctdb->ev,
+					  queue_process_event, queue);
 	}
 
 	/* It is the responsibility of the callback to free 'data' */
@@ -192,8 +193,8 @@ failed:
 
 
 /* used when an event triggers a dead queue */
-static void queue_dead(struct event_context *ev, struct timed_event *te, 
-		       struct timeval t, void *private_data)
+static void queue_dead(struct event_context *ev, struct tevent_immediate *im,
+		       void *private_data)
 {
 	struct ctdb_queue *queue = talloc_get_type(private_data, struct ctdb_queue);
 	queue->callback(NULL, 0, queue->private_data);
@@ -224,8 +225,8 @@ static void queue_io_write(struct ctdb_queue *queue)
 			talloc_free(queue->fde);
 			queue->fde = NULL;
 			queue->fd = -1;
-			event_add_timed(queue->ctdb->ev, queue, timeval_zero(), 
-					queue_dead, queue);
+			tevent_schedule_immediate(queue->im, queue->ctdb->ev,
+						  queue_dead, queue);
 			return;
 		}
 		if (n <= 0) return;
@@ -291,8 +292,8 @@ int ctdb_queue_send(struct ctdb_queue *queue, uint8_t *data, uint32_t length)
 			talloc_free(queue->fde);
 			queue->fde = NULL;
 			queue->fd = -1;
-			event_add_timed(queue->ctdb->ev, queue, timeval_zero(), 
-					queue_dead, queue);
+			tevent_schedule_immediate(queue->im, queue->ctdb->ev,
+						  queue_dead, queue);
 			/* yes, we report success, as the dead node is 
 			   handled via a separate event */
 			return 0;
@@ -402,6 +403,9 @@ struct ctdb_queue *ctdb_queue_setup(struct ctdb_context *ctdb,
 	va_end(ap);
 	CTDB_NO_MEMORY_NULL(ctdb, queue->name);
 
+	queue->im= tevent_create_immediate(queue);
+	CTDB_NO_MEMORY_NULL(ctdb, queue->im);
+
 	queue->ctdb = ctdb;
 	queue->fd = fd;
 	queue->alignment = alignment;
diff --git a/common/ctdb_message.c b/common/ctdb_message.c
index 5fc7b22..50d2189 100644
--- a/common/ctdb_message.c
+++ b/common/ctdb_message.c
@@ -2,6 +2,7 @@
    ctdb_message protocol code
 
    Copyright (C) Andrew Tridgell  2007
+   Copyright (C) Amitay Isaacs  2013
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -27,16 +28,103 @@
 #include "../include/ctdb_private.h"
 #include "lib/util/dlinklist.h"
 
+static int message_list_db_init(struct ctdb_context *ctdb)
+{
+	ctdb->message_list_indexdb = tdb_open("messagedb", 8192,
+					      TDB_INTERNAL|TDB_DISALLOW_NESTING,
+					      O_RDWR|O_CREAT, 0);
+	if (ctdb->message_list_indexdb == NULL) {
+		DEBUG(DEBUG_ERR, ("Failed to create message list indexdb\n"));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int message_list_db_add(struct ctdb_context *ctdb, TDB_DATA key, TDB_DATA data)
+{
+	int ret;
+
+	if (ctdb->message_list_indexdb == NULL) {
+		ret = message_list_db_init(ctdb);
+		if (ret < 0) {
+			return -1;
+		}
+	}
+
+	ret = tdb_store(ctdb->message_list_indexdb, key, data, TDB_INSERT);
+	if (ret < 0) {
+		DEBUG(DEBUG_ERR, ("Failed to add message list handler (%s)\n",
+				  tdb_errorstr(ctdb->message_list_indexdb)));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int message_list_db_delete(struct ctdb_context *ctdb, TDB_DATA key)
+{
+	int ret;
+
+	if (ctdb->message_list_indexdb == NULL) {
+		return -1;
+	}
+
+	ret = tdb_delete(ctdb->message_list_indexdb, key);
+	if (ret < 0) {
+		DEBUG(DEBUG_ERR, ("Failed to delete message list handler (%s)\n",
+				  tdb_errorstr(ctdb->message_list_indexdb)));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int message_list_db_fetch(struct ctdb_context *ctdb, TDB_DATA key, TDB_DATA *data)
+{
+	if (ctdb->message_list_indexdb == NULL) {
+		return -1;
+	}
+
+	*data = tdb_fetch(ctdb->message_list_indexdb, key);
+	if (data->dsize == 0) {
+		return -1;
+	}
+	return 0;
+}
+
 /*
   this dispatches the messages to the registered ctdb message handler
 */
 int ctdb_dispatch_message(struct ctdb_context *ctdb, uint64_t srvid, TDB_DATA data)
 {
-	struct ctdb_message_list *ml;
+	struct ctdb_message_list_header *h;
+	struct ctdb_message_list *m;
+	TDB_DATA key, hdata;
+	uint64_t srvid_all = CTDB_SRVID_ALL;
+	int ret;
+
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	ret = message_list_db_fetch(ctdb, key, &hdata);
+	if (ret == 0) {
+		h = *(struct ctdb_message_list_header **)hdata.dptr;
 
-	for (ml=ctdb->message_list;ml;ml=ml->next) {
-		if (ml->srvid == srvid || ml->srvid == CTDB_SRVID_ALL) {
-			ml->message_handler(ctdb, srvid, data, ml->message_private);
+		for (m=h->m; m; m=m->next) {
+			m->message_handler(ctdb, srvid, data, m->message_private);
+		}
+	}
+
+	key.dptr = (uint8_t *)&srvid_all;
+	key.dsize = sizeof(uint64_t);
+
+	ret = message_list_db_fetch(ctdb, key, &hdata);
+	if (ret == 0) {
+		h = *(struct ctdb_message_list_header **)hdata.dptr;
+
+		for(m=h->m; m; m=m->next) {
+			m->message_handler(ctdb, srvid, data, m->message_private);
 		}
 	}
 
@@ -57,13 +145,37 @@ void ctdb_request_message(struct ctdb_context *ctdb, struct ctdb_req_header *hdr
 	ctdb_dispatch_message(ctdb, c->srvid, data);
 }
 
+/*
+ * When header is freed, remove all the srvid handlers
+ */
+static int message_header_destructor(struct ctdb_message_list_header *h)
+{
+	struct ctdb_message_list *m;
+	TDB_DATA key;
+
+	while (h->m != NULL) {
+		m = h->m;
+		DLIST_REMOVE(h->m, m);
+		TALLOC_FREE(m);
+	}
+
+	key.dptr = (uint8_t *)&h->srvid;
+	key.dsize = sizeof(uint64_t);
+
+	message_list_db_delete(h->ctdb, key);
+	DLIST_REMOVE(h->ctdb->message_list_header, h);
+
+	return 0;
+}
 
 /*
   when a client goes away, we need to remove its srvid handler from the list
  */
 static int message_handler_destructor(struct ctdb_message_list *m)
 {
-	DLIST_REMOVE(m->ctdb->message_list, m);
+	struct ctdb_message_list_header *h = m->h;
+
+	DLIST_REMOVE(h->m, m);
 	return 0;
 }
 
@@ -76,20 +188,47 @@ int ctdb_register_message_handler(struct ctdb_context *ctdb,
 				  ctdb_msg_fn_t handler,
 				  void *private_data)
 {
+	struct ctdb_message_list_header *h;
 	struct ctdb_message_list *m;
+	TDB_DATA key, data;
+	int ret;
 
-	m = talloc(mem_ctx, struct ctdb_message_list);
+	m = talloc_zero(mem_ctx, struct ctdb_message_list);
 	CTDB_NO_MEMORY(ctdb, m);
 
-	m->ctdb            = ctdb;
-	m->srvid           = srvid;
 	m->message_handler = handler;
 	m->message_private = private_data;
-	
-	DLIST_ADD(ctdb->message_list, m);
 
-	talloc_set_destructor(m, message_handler_destructor);
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	ret = message_list_db_fetch(ctdb, key, &data);
+	if (ret < 0) {
+		/* srvid not registered yet */
+		h = talloc_zero(ctdb, struct ctdb_message_list_header);
+		CTDB_NO_MEMORY(ctdb, h);
+
+		h->ctdb = ctdb;
+		h->srvid = srvid;
+
+		data.dptr = (uint8_t *)&h;
+		data.dsize = sizeof(struct ctdb_message_list_header *);
+		ret = message_list_db_add(ctdb, key, data);
+		if (ret < 0) {
+			talloc_free(m);
+			talloc_free(h);
+			return -1;
+		}
 
+		DLIST_ADD(ctdb->message_list_header, h);
+		talloc_set_destructor(h, message_header_destructor);
+	} else {
+		h = *(struct ctdb_message_list_header **)data.dptr;
+	}
+
+	m->h = h;
+	DLIST_ADD(h->m, m);
+	talloc_set_destructor(m, message_handler_destructor);
 	return 0;
 }
 
@@ -99,13 +238,53 @@ int ctdb_register_message_handler(struct ctdb_context *ctdb,
 */
 int ctdb_deregister_message_handler(struct ctdb_context *ctdb, uint64_t srvid, void *private_data)
 {
+	struct ctdb_message_list_header *h;
 	struct ctdb_message_list *m;
+	TDB_DATA key, data;
+	int ret;
+
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	ret = message_list_db_fetch(ctdb, key, &data);
+	if (ret < 0) {
+		return -1;
+	}
 
-	for (m=ctdb->message_list;m;m=m->next) {
-		if (m->srvid == srvid && m->message_private == private_data) {
+	h = *(struct ctdb_message_list_header **)data.dptr;
+	for (m=h->m; m; m=m->next) {
+		if (m->message_private == private_data) {
 			talloc_free(m);
+			if (h->m == NULL) {
+				talloc_free(h);
+			}
 			return 0;
 		}
 	}
+
 	return -1;
 }
+
+
+/*
+ * check if the given srvid exists
+ */
+bool ctdb_check_message_handler(struct ctdb_context *ctdb, uint64_t srvid)
+{
+	struct ctdb_message_list_header *h;
+	TDB_DATA key, data;
+
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	if (message_list_db_fetch(ctdb, key, &data) < 0) {
+		return false;
+	}
+
+	h = *(struct ctdb_message_list_header **)data.dptr;
+	if (h->m == NULL) {
+		return false;
+	}
+
+	return true;
+}
diff --git a/include/ctdb_private.h b/include/ctdb_private.h
index 7794c4c..7e46603 100644
--- a/include/ctdb_private.h
+++ b/include/ctdb_private.h
@@ -286,10 +286,15 @@ struct ctdb_upcalls {
 
 /* list of message handlers - needs to be changed to a more efficient data
    structure so we can find a message handler given a srvid quickly */
-struct ctdb_message_list {
+struct ctdb_message_list_header {
+	struct ctdb_message_list_header *next, *prev;
 	struct ctdb_context *ctdb;
-	struct ctdb_message_list *next, *prev;
 	uint64_t srvid;
+	struct ctdb_message_list *m;
+};
+struct ctdb_message_list {
+	struct ctdb_message_list *next, *prev;
+	struct ctdb_message_list_header *h;
 	ctdb_msg_fn_t message_handler;
 	void *message_private;
 };
@@ -478,7 +483,8 @@ struct ctdb_context {
 	const struct ctdb_upcalls *upcalls; /* transport upcalls */
 	void *private_data; /* private to transport */
 	struct ctdb_db_context *db_list;
-	struct ctdb_message_list *message_list;
+	struct ctdb_message_list_header *message_list_header;
+	struct tdb_context *message_list_indexdb;
 	struct ctdb_daemon_data daemon;
 	struct ctdb_statistics statistics;
 	struct ctdb_statistics statistics_current;
@@ -1014,6 +1020,7 @@ int32_t ctdb_control_traverse_kill(struct ctdb_context *ctdb, TDB_DATA indata,
 				    TDB_DATA *outdata, uint32_t srcnode);
 
 int ctdb_dispatch_message(struct ctdb_context *ctdb, uint64_t srvid, TDB_DATA data);
+bool ctdb_check_message_handler(struct ctdb_context *ctdb, uint64_t srvid);
 
 int daemon_register_message_handler(struct ctdb_context *ctdb, uint32_t client_id, uint64_t srvid);
 int ctdb_deregister_message_handler(struct ctdb_context *ctdb, uint64_t srvid, void *private_data);
diff --git a/server/ctdb_daemon.c b/server/ctdb_daemon.c
index 0550fab..983f62d 100644
--- a/server/ctdb_daemon.c
+++ b/server/ctdb_daemon.c
@@ -225,13 +225,7 @@ int daemon_check_srvids(struct ctdb_context *ctdb, TDB_DATA indata,
 		return -1;
 	}
 	for (i=0; i<num_ids; i++) {
-		struct ctdb_message_list *ml;
-		for (ml=ctdb->message_list; ml; ml=ml->next) {
-			if (ml->srvid == ids[i]) {
-				break;
-			}
-		}
-		if (ml != NULL) {
+		if (ctdb_check_message_handler(ctdb, ids[i])) {
 			results[i/8] |= (1 << (i%8));
 		}
 	}


-- 
CTDB repository


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