2 ctdb_call protocol code
4 Copyright (C) Andrew Tridgell 2006
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, see <http://www.gnu.org/licenses/>.
20 see http://wiki.samba.org/index.php/Samba_%26_Clustering for
21 protocol design and packet details
24 #include "lib/events/events.h"
25 #include "lib/tdb/include/tdb.h"
26 #include "lib/util/dlinklist.h"
27 #include "system/network.h"
28 #include "system/filesys.h"
29 #include "../include/ctdb_private.h"
32 find the ctdb_db from a db index
34 struct ctdb_db_context *find_ctdb_db(struct ctdb_context *ctdb, uint32_t id)
36 struct ctdb_db_context *ctdb_db;
38 for (ctdb_db=ctdb->db_list; ctdb_db; ctdb_db=ctdb_db->next) {
39 if (ctdb_db->db_id == id) {
48 a varient of input packet that can be used in lock requeue
50 static void ctdb_call_input_pkt(void *p, struct ctdb_req_header *hdr)
52 struct ctdb_context *ctdb = talloc_get_type(p, struct ctdb_context);
53 ctdb_input_pkt(ctdb, hdr);
60 static void ctdb_send_error(struct ctdb_context *ctdb,
61 struct ctdb_req_header *hdr, uint32_t status,
62 const char *fmt, ...) PRINTF_ATTRIBUTE(4,5);
63 static void ctdb_send_error(struct ctdb_context *ctdb,
64 struct ctdb_req_header *hdr, uint32_t status,
68 struct ctdb_reply_error *r;
73 msg = talloc_vasprintf(ctdb, fmt, ap);
75 ctdb_fatal(ctdb, "Unable to allocate error in ctdb_send_error\n");
79 msglen = strlen(msg)+1;
80 len = offsetof(struct ctdb_reply_error, msg);
81 r = ctdb_transport_allocate(ctdb, msg, CTDB_REPLY_ERROR, len + msglen,
82 struct ctdb_reply_error);
83 CTDB_NO_MEMORY_FATAL(ctdb, r);
85 r->hdr.destnode = hdr->srcnode;
86 r->hdr.reqid = hdr->reqid;
89 memcpy(&r->msg[0], msg, msglen);
91 ctdb_queue_packet(ctdb, &r->hdr);
100 static void ctdb_call_send_redirect(struct ctdb_context *ctdb,
102 struct ctdb_req_call *c,
103 struct ctdb_ltdb_header *header)
106 uint32_t lmaster = ctdb_lmaster(ctdb, &key);
107 if (ctdb->pnn == lmaster) {
108 c->hdr.destnode = header->dmaster;
109 } else if ((c->hopcount % ctdb->tunable.max_redirect_count) == 0) {
110 c->hdr.destnode = lmaster;
112 c->hdr.destnode = header->dmaster;
115 ctdb_queue_packet(ctdb, &c->hdr);
122 caller must have the chainlock before calling this routine. Caller must be
125 static void ctdb_send_dmaster_reply(struct ctdb_db_context *ctdb_db,
126 struct ctdb_ltdb_header *header,
127 TDB_DATA key, TDB_DATA data,
128 uint32_t new_dmaster,
131 struct ctdb_context *ctdb = ctdb_db->ctdb;
132 struct ctdb_reply_dmaster *r;
136 if (ctdb->pnn != ctdb_lmaster(ctdb, &key)) {
137 DEBUG(0,(__location__ " Caller is not lmaster!\n"));
141 header->dmaster = new_dmaster;
142 ret = ctdb_ltdb_store(ctdb_db, key, header, data);
144 ctdb_fatal(ctdb, "ctdb_req_dmaster unable to update dmaster");
148 /* put the packet on a temporary context, allowing us to safely free
149 it below even if ctdb_reply_dmaster() has freed it already */
150 tmp_ctx = talloc_new(ctdb);
152 /* send the CTDB_REPLY_DMASTER */
153 len = offsetof(struct ctdb_reply_dmaster, data) + key.dsize + data.dsize;
154 r = ctdb_transport_allocate(ctdb, tmp_ctx, CTDB_REPLY_DMASTER, len,
155 struct ctdb_reply_dmaster);
156 CTDB_NO_MEMORY_FATAL(ctdb, r);
158 r->hdr.destnode = new_dmaster;
159 r->hdr.reqid = reqid;
160 r->rsn = header->rsn;
161 r->keylen = key.dsize;
162 r->datalen = data.dsize;
163 r->db_id = ctdb_db->db_id;
164 memcpy(&r->data[0], key.dptr, key.dsize);
165 memcpy(&r->data[key.dsize], data.dptr, data.dsize);
167 ctdb_queue_packet(ctdb, &r->hdr);
169 talloc_free(tmp_ctx);
173 send a dmaster request (give another node the dmaster for a record)
175 This is always sent to the lmaster, which ensures that the lmaster
176 always knows who the dmaster is. The lmaster will then send a
177 CTDB_REPLY_DMASTER to the new dmaster
179 static void ctdb_call_send_dmaster(struct ctdb_db_context *ctdb_db,
180 struct ctdb_req_call *c,
181 struct ctdb_ltdb_header *header,
182 TDB_DATA *key, TDB_DATA *data)
184 struct ctdb_req_dmaster *r;
185 struct ctdb_context *ctdb = ctdb_db->ctdb;
187 uint32_t lmaster = ctdb_lmaster(ctdb, key);
189 if (lmaster == ctdb->pnn) {
190 ctdb_send_dmaster_reply(ctdb_db, header, *key, *data,
191 c->hdr.srcnode, c->hdr.reqid);
195 len = offsetof(struct ctdb_req_dmaster, data) + key->dsize + data->dsize;
196 r = ctdb_transport_allocate(ctdb, ctdb, CTDB_REQ_DMASTER, len,
197 struct ctdb_req_dmaster);
198 CTDB_NO_MEMORY_FATAL(ctdb, r);
199 r->hdr.destnode = lmaster;
200 r->hdr.reqid = c->hdr.reqid;
202 r->rsn = header->rsn;
203 r->dmaster = c->hdr.srcnode;
204 r->keylen = key->dsize;
205 r->datalen = data->dsize;
206 memcpy(&r->data[0], key->dptr, key->dsize);
207 memcpy(&r->data[key->dsize], data->dptr, data->dsize);
209 header->dmaster = c->hdr.srcnode;
210 if (ctdb_ltdb_store(ctdb_db, *key, header, *data) != 0) {
211 ctdb_fatal(ctdb, "Failed to store record in ctdb_call_send_dmaster");
214 ctdb_queue_packet(ctdb, &r->hdr);
220 called when a CTDB_REPLY_DMASTER packet comes in, or when the lmaster
221 gets a CTDB_REQUEST_DMASTER for itself. We become the dmaster.
223 must be called with the chainlock held. This function releases the chainlock
225 static void ctdb_become_dmaster(struct ctdb_db_context *ctdb_db,
226 struct ctdb_req_header *hdr,
227 TDB_DATA key, TDB_DATA data,
230 struct ctdb_call_state *state;
231 struct ctdb_context *ctdb = ctdb_db->ctdb;
232 struct ctdb_ltdb_header header;
234 DEBUG(DEBUG_INFO,("pnn %u dmaster response %08x\n", ctdb->pnn, ctdb_hash(&key)));
237 header.rsn = rsn + 1;
238 header.dmaster = ctdb->pnn;
240 if (ctdb_ltdb_store(ctdb_db, key, &header, data) != 0) {
241 ctdb_fatal(ctdb, "ctdb_reply_dmaster store failed\n");
242 ctdb_ltdb_unlock(ctdb_db, key);
246 state = ctdb_reqid_find(ctdb, hdr->reqid, struct ctdb_call_state);
249 DEBUG(0,("pnn %u Invalid reqid %u in ctdb_become_dmaster from node %u\n",
250 ctdb->pnn, hdr->reqid, hdr->srcnode));
251 ctdb_ltdb_unlock(ctdb_db, key);
255 if (hdr->reqid != state->reqid) {
256 /* we found a record but it was the wrong one */
257 DEBUG(0, ("Dropped orphan in ctdb_become_dmaster with reqid:%u\n from node %u", hdr->reqid, hdr->srcnode));
258 ctdb_ltdb_unlock(ctdb_db, key);
262 ctdb_call_local(ctdb_db, &state->call, &header, state, &data, ctdb->pnn);
264 ctdb_ltdb_unlock(ctdb_db, state->call.key);
266 state->state = CTDB_CALL_DONE;
267 if (state->async.fn) {
268 state->async.fn(state);
275 called when a CTDB_REQ_DMASTER packet comes in
277 this comes into the lmaster for a record when the current dmaster
278 wants to give up the dmaster role and give it to someone else
280 void ctdb_request_dmaster(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
282 struct ctdb_req_dmaster *c = (struct ctdb_req_dmaster *)hdr;
283 TDB_DATA key, data, data2;
284 struct ctdb_ltdb_header header;
285 struct ctdb_db_context *ctdb_db;
289 key.dsize = c->keylen;
290 data.dptr = c->data + c->keylen;
291 data.dsize = c->datalen;
293 ctdb_db = find_ctdb_db(ctdb, c->db_id);
295 ctdb_send_error(ctdb, hdr, -1,
296 "Unknown database in request. db_id==0x%08x",
301 /* fetch the current record */
302 ret = ctdb_ltdb_lock_fetch_requeue(ctdb_db, key, &header, hdr, &data2,
303 ctdb_call_input_pkt, ctdb, False);
305 ctdb_fatal(ctdb, "ctdb_req_dmaster failed to fetch record");
309 DEBUG(DEBUG_INFO,(__location__ " deferring ctdb_request_dmaster\n"));
313 if (ctdb_lmaster(ctdb, &key) != ctdb->pnn) {
314 DEBUG(0,("pnn %u dmaster request to non-lmaster lmaster=%u gen=%u curgen=%u\n",
315 ctdb->pnn, ctdb_lmaster(ctdb, &key),
316 hdr->generation, ctdb->vnn_map->generation));
317 ctdb_fatal(ctdb, "ctdb_req_dmaster to non-lmaster");
320 DEBUG(DEBUG_INFO,("pnn %u dmaster request on %08x for %u from %u\n",
321 ctdb->pnn, ctdb_hash(&key), c->dmaster, c->hdr.srcnode));
323 /* its a protocol error if the sending node is not the current dmaster */
324 if (header.dmaster != hdr->srcnode) {
325 DEBUG(0,("pnn %u dmaster request for new-dmaster %u from non-master %u real-dmaster=%u key %08x dbid 0x%08x gen=%u curgen=%u c->rsn=%llu header.rsn=%llu reqid=%u keyval=0x%08x\n",
326 ctdb->pnn, c->dmaster, hdr->srcnode, header.dmaster, ctdb_hash(&key),
327 ctdb_db->db_id, hdr->generation, ctdb->vnn_map->generation,
328 (unsigned long long)c->rsn, (unsigned long long)header.rsn, c->hdr.reqid,
329 (key.dsize >= 4)?(*(uint32_t *)key.dptr):0));
330 if (header.rsn != 0 || header.dmaster != ctdb->pnn) {
331 ctdb_fatal(ctdb, "ctdb_req_dmaster from non-master");
336 if (header.rsn > c->rsn) {
337 DEBUG(0,("pnn %u dmaster request with older RSN new-dmaster %u from %u real-dmaster=%u key %08x dbid 0x%08x gen=%u curgen=%u c->rsn=%llu header.rsn=%llu reqid=%u\n",
338 ctdb->pnn, c->dmaster, hdr->srcnode, header.dmaster, ctdb_hash(&key),
339 ctdb_db->db_id, hdr->generation, ctdb->vnn_map->generation,
340 (unsigned long long)c->rsn, (unsigned long long)header.rsn, c->hdr.reqid));
343 /* use the rsn from the sending node */
346 /* check if the new dmaster is the lmaster, in which case we
347 skip the dmaster reply */
348 if (c->dmaster == ctdb->pnn) {
349 ctdb_become_dmaster(ctdb_db, hdr, key, data, c->rsn);
351 ctdb_send_dmaster_reply(ctdb_db, &header, key, data, c->dmaster, hdr->reqid);
352 ctdb_ltdb_unlock(ctdb_db, key);
358 called when a CTDB_REQ_CALL packet comes in
360 void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
362 struct ctdb_req_call *c = (struct ctdb_req_call *)hdr;
364 struct ctdb_reply_call *r;
366 struct ctdb_ltdb_header header;
367 struct ctdb_call call;
368 struct ctdb_db_context *ctdb_db;
370 ctdb_db = find_ctdb_db(ctdb, c->db_id);
372 ctdb_send_error(ctdb, hdr, -1,
373 "Unknown database in request. db_id==0x%08x",
378 call.call_id = c->callid;
379 call.key.dptr = c->data;
380 call.key.dsize = c->keylen;
381 call.call_data.dptr = c->data + c->keylen;
382 call.call_data.dsize = c->calldatalen;
384 /* determine if we are the dmaster for this key. This also
385 fetches the record data (if any), thus avoiding a 2nd fetch of the data
386 if the call will be answered locally */
388 ret = ctdb_ltdb_lock_fetch_requeue(ctdb_db, call.key, &header, hdr, &data,
389 ctdb_call_input_pkt, ctdb, False);
391 ctdb_send_error(ctdb, hdr, ret, "ltdb fetch failed in ctdb_request_call");
395 DEBUG(DEBUG_INFO,(__location__ " deferred ctdb_request_call\n"));
399 /* if we are not the dmaster, then send a redirect to the
401 if (header.dmaster != ctdb->pnn) {
402 talloc_free(data.dptr);
403 ctdb_call_send_redirect(ctdb, call.key, c, &header);
404 ctdb_ltdb_unlock(ctdb_db, call.key);
408 if (c->hopcount > ctdb->statistics.max_hop_count) {
409 ctdb->statistics.max_hop_count = c->hopcount;
412 /* if this nodes has done enough consecutive calls on the same record
413 then give them the record
414 or if the node requested an immediate migration
416 if ( c->hdr.srcnode != ctdb->pnn &&
417 ((header.laccessor == c->hdr.srcnode
418 && header.lacount >= ctdb->tunable.max_lacount)
419 || (c->flags & CTDB_IMMEDIATE_MIGRATION)) ) {
420 DEBUG(DEBUG_INFO,("pnn %u starting migration of %08x to %u\n",
421 ctdb->pnn, ctdb_hash(&call.key), c->hdr.srcnode));
422 ctdb_call_send_dmaster(ctdb_db, c, &header, &call.key, &data);
423 talloc_free(data.dptr);
424 ctdb_ltdb_unlock(ctdb_db, call.key);
428 ctdb_call_local(ctdb_db, &call, &header, hdr, &data, c->hdr.srcnode);
430 ctdb_ltdb_unlock(ctdb_db, call.key);
432 len = offsetof(struct ctdb_reply_call, data) + call.reply_data.dsize;
433 r = ctdb_transport_allocate(ctdb, ctdb, CTDB_REPLY_CALL, len,
434 struct ctdb_reply_call);
435 CTDB_NO_MEMORY_FATAL(ctdb, r);
436 r->hdr.destnode = hdr->srcnode;
437 r->hdr.reqid = hdr->reqid;
438 r->status = call.status;
439 r->datalen = call.reply_data.dsize;
440 if (call.reply_data.dsize) {
441 memcpy(&r->data[0], call.reply_data.dptr, call.reply_data.dsize);
444 ctdb_queue_packet(ctdb, &r->hdr);
450 called when a CTDB_REPLY_CALL packet comes in
452 This packet comes in response to a CTDB_REQ_CALL request packet. It
453 contains any reply data from the call
455 void ctdb_reply_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
457 struct ctdb_reply_call *c = (struct ctdb_reply_call *)hdr;
458 struct ctdb_call_state *state;
460 state = ctdb_reqid_find(ctdb, hdr->reqid, struct ctdb_call_state);
462 DEBUG(0, (__location__ " reqid %u not found\n", hdr->reqid));
466 if (hdr->reqid != state->reqid) {
467 /* we found a record but it was the wrong one */
468 DEBUG(0, ("Dropped orphaned call reply with reqid:%u\n",hdr->reqid));
472 state->call.reply_data.dptr = c->data;
473 state->call.reply_data.dsize = c->datalen;
474 state->call.status = c->status;
476 talloc_steal(state, c);
478 state->state = CTDB_CALL_DONE;
479 if (state->async.fn) {
480 state->async.fn(state);
486 called when a CTDB_REPLY_DMASTER packet comes in
488 This packet comes in from the lmaster response to a CTDB_REQ_CALL
489 request packet. It means that the current dmaster wants to give us
492 void ctdb_reply_dmaster(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
494 struct ctdb_reply_dmaster *c = (struct ctdb_reply_dmaster *)hdr;
495 struct ctdb_db_context *ctdb_db;
499 ctdb_db = find_ctdb_db(ctdb, c->db_id);
500 if (ctdb_db == NULL) {
501 DEBUG(0,("Unknown db_id 0x%x in ctdb_reply_dmaster\n", c->db_id));
506 key.dsize = c->keylen;
507 data.dptr = &c->data[key.dsize];
508 data.dsize = c->datalen;
510 ret = ctdb_ltdb_lock_requeue(ctdb_db, key, hdr,
511 ctdb_call_input_pkt, ctdb, False);
516 DEBUG(0,(__location__ " Failed to get lock in ctdb_reply_dmaster\n"));
520 ctdb_become_dmaster(ctdb_db, hdr, key, data, c->rsn);
525 called when a CTDB_REPLY_ERROR packet comes in
527 void ctdb_reply_error(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
529 struct ctdb_reply_error *c = (struct ctdb_reply_error *)hdr;
530 struct ctdb_call_state *state;
532 state = ctdb_reqid_find(ctdb, hdr->reqid, struct ctdb_call_state);
534 DEBUG(0,("pnn %u Invalid reqid %u in ctdb_reply_error\n",
535 ctdb->pnn, hdr->reqid));
539 if (hdr->reqid != state->reqid) {
540 /* we found a record but it was the wrong one */
541 DEBUG(0, ("Dropped orphaned error reply with reqid:%u\n",hdr->reqid));
545 talloc_steal(state, c);
547 state->state = CTDB_CALL_ERROR;
548 state->errmsg = (char *)c->msg;
549 if (state->async.fn) {
550 state->async.fn(state);
558 static int ctdb_call_destructor(struct ctdb_call_state *state)
560 DLIST_REMOVE(state->ctdb_db->ctdb->pending_calls, state);
561 ctdb_reqid_remove(state->ctdb_db->ctdb, state->reqid);
567 called when a ctdb_call needs to be resent after a reconfigure event
569 static void ctdb_call_resend(struct ctdb_call_state *state)
571 struct ctdb_context *ctdb = state->ctdb_db->ctdb;
573 state->generation = ctdb->vnn_map->generation;
575 /* use a new reqid, in case the old reply does eventually come in */
576 ctdb_reqid_remove(ctdb, state->reqid);
577 state->reqid = ctdb_reqid_new(ctdb, state);
578 state->c->hdr.reqid = state->reqid;
580 /* update the generation count for this request, so its valid with the new vnn_map */
581 state->c->hdr.generation = state->generation;
583 /* send the packet to ourselves, it will be redirected appropriately */
584 state->c->hdr.destnode = ctdb->pnn;
586 ctdb_queue_packet(ctdb, &state->c->hdr);
587 DEBUG(0,("resent ctdb_call\n"));
591 resend all pending calls on recovery
593 void ctdb_call_resend_all(struct ctdb_context *ctdb)
595 struct ctdb_call_state *state, *next;
596 for (state=ctdb->pending_calls;state;state=next) {
598 ctdb_call_resend(state);
603 this allows the caller to setup a async.fn
605 static void call_local_trigger(struct event_context *ev, struct timed_event *te,
606 struct timeval t, void *private_data)
608 struct ctdb_call_state *state = talloc_get_type(private_data, struct ctdb_call_state);
609 if (state->async.fn) {
610 state->async.fn(state);
616 construct an event driven local ctdb_call
618 this is used so that locally processed ctdb_call requests are processed
619 in an event driven manner
621 struct ctdb_call_state *ctdb_call_local_send(struct ctdb_db_context *ctdb_db,
622 struct ctdb_call *call,
623 struct ctdb_ltdb_header *header,
626 struct ctdb_call_state *state;
627 struct ctdb_context *ctdb = ctdb_db->ctdb;
630 state = talloc_zero(ctdb_db, struct ctdb_call_state);
631 CTDB_NO_MEMORY_NULL(ctdb, state);
633 talloc_steal(state, data->dptr);
635 state->state = CTDB_CALL_DONE;
637 state->ctdb_db = ctdb_db;
639 ret = ctdb_call_local(ctdb_db, &state->call, header, state, data, ctdb->pnn);
641 event_add_timed(ctdb->ev, state, timeval_zero(), call_local_trigger, state);
648 make a remote ctdb call - async send. Called in daemon context.
650 This constructs a ctdb_call request and queues it for processing.
651 This call never blocks.
653 struct ctdb_call_state *ctdb_daemon_call_send_remote(struct ctdb_db_context *ctdb_db,
654 struct ctdb_call *call,
655 struct ctdb_ltdb_header *header)
658 struct ctdb_call_state *state;
659 struct ctdb_context *ctdb = ctdb_db->ctdb;
661 state = talloc_zero(ctdb_db, struct ctdb_call_state);
662 CTDB_NO_MEMORY_NULL(ctdb, state);
663 state->reqid = ctdb_reqid_new(ctdb, state);
664 state->ctdb_db = ctdb_db;
665 talloc_set_destructor(state, ctdb_call_destructor);
667 len = offsetof(struct ctdb_req_call, data) + call->key.dsize + call->call_data.dsize;
668 state->c = ctdb_transport_allocate(ctdb, state, CTDB_REQ_CALL, len,
669 struct ctdb_req_call);
670 CTDB_NO_MEMORY_NULL(ctdb, state->c);
671 state->c->hdr.destnode = header->dmaster;
673 /* this limits us to 16k outstanding messages - not unreasonable */
674 state->c->hdr.reqid = state->reqid;
675 state->c->flags = call->flags;
676 state->c->db_id = ctdb_db->db_id;
677 state->c->callid = call->call_id;
678 state->c->hopcount = 0;
679 state->c->keylen = call->key.dsize;
680 state->c->calldatalen = call->call_data.dsize;
681 memcpy(&state->c->data[0], call->key.dptr, call->key.dsize);
682 memcpy(&state->c->data[call->key.dsize],
683 call->call_data.dptr, call->call_data.dsize);
685 state->call.call_data.dptr = &state->c->data[call->key.dsize];
686 state->call.key.dptr = &state->c->data[0];
688 state->state = CTDB_CALL_WAIT;
689 state->generation = ctdb->vnn_map->generation;
691 DLIST_ADD(ctdb->pending_calls, state);
693 ctdb_queue_packet(ctdb, &state->c->hdr);
699 make a remote ctdb call - async recv - called in daemon context
701 This is called when the program wants to wait for a ctdb_call to complete and get the
702 results. This call will block unless the call has already completed.
704 int ctdb_daemon_call_recv(struct ctdb_call_state *state, struct ctdb_call *call)
706 while (state->state < CTDB_CALL_DONE) {
707 event_loop_once(state->ctdb_db->ctdb->ev);
709 if (state->state != CTDB_CALL_DONE) {
710 ctdb_set_error(state->ctdb_db->ctdb, "%s", state->errmsg);
715 if (state->call.reply_data.dsize) {
716 call->reply_data.dptr = talloc_memdup(state->ctdb_db->ctdb,
717 state->call.reply_data.dptr,
718 state->call.reply_data.dsize);
719 call->reply_data.dsize = state->call.reply_data.dsize;
721 call->reply_data.dptr = NULL;
722 call->reply_data.dsize = 0;
724 call->status = state->call.status;
731 send a keepalive packet to the other node
733 void ctdb_send_keepalive(struct ctdb_context *ctdb, uint32_t destnode)
735 struct ctdb_req_keepalive *r;
737 r = ctdb_transport_allocate(ctdb, ctdb, CTDB_REQ_KEEPALIVE,
738 sizeof(struct ctdb_req_keepalive),
739 struct ctdb_req_keepalive);
740 CTDB_NO_MEMORY_FATAL(ctdb, r);
741 r->hdr.destnode = destnode;
744 ctdb->statistics.keepalive_packets_sent++;
746 ctdb_queue_packet(ctdb, &r->hdr);