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samba-mirror/ctdb/server/ctdb_keepalive.c
Martin Schwenke 8c2ff3f2b5 ctdb-daemon: Add an environment variable to set version
This can be used to test the version checking logic.  Cache the
version to avoid re-checking the environment variable each time.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@samba.org>
2019-03-15 05:17:14 +00:00

235 lines
5.4 KiB
C

/*
monitoring links to all other nodes to detect dead nodes
Copyright (C) Ronnie Sahlberg 2007
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
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/filesys.h"
#include "system/network.h"
#include "system/time.h"
#include "system/wait.h"
#include <talloc.h>
#include <tevent.h>
#include "lib/util/debug.h"
#include "lib/util/samba_util.h"
#include "ctdb_private.h"
#include "version.h"
#include "common/common.h"
#include "common/logging.h"
static uint32_t keepalive_version(void)
{
static uint32_t version = 0;
if (version == 0) {
const char *t;
version = (SAMBA_VERSION_MAJOR << 16) | SAMBA_VERSION_MINOR;
t = getenv("CTDB_TEST_SAMBA_VERSION");
if (t != NULL) {
int v;
v = atoi(t);
if (v <= 0) {
DBG_WARNING("Failed to parse env var: %s\n", t);
} else {
version = v;
}
}
}
return version;
}
static uint32_t keepalive_uptime(struct ctdb_context *ctdb)
{
struct timeval current = tevent_timeval_current();
return current.tv_sec - ctdb->ctdbd_start_time.tv_sec;
}
/*
send a keepalive packet to the other node
*/
static void ctdb_send_keepalive(struct ctdb_context *ctdb, uint32_t destnode)
{
struct ctdb_req_keepalive_old *r;
if (ctdb->methods == NULL) {
DEBUG(DEBUG_INFO,
("Failed to send keepalive. Transport is DOWN\n"));
return;
}
r = ctdb_transport_allocate(ctdb, ctdb, CTDB_REQ_KEEPALIVE,
sizeof(struct ctdb_req_keepalive_old),
struct ctdb_req_keepalive_old);
CTDB_NO_MEMORY_FATAL(ctdb, r);
r->hdr.destnode = destnode;
r->hdr.reqid = 0;
r->version = keepalive_version();
r->uptime = keepalive_uptime(ctdb);
CTDB_INCREMENT_STAT(ctdb, keepalive_packets_sent);
ctdb_queue_packet(ctdb, &r->hdr);
talloc_free(r);
}
/*
see if any nodes are dead
*/
static void ctdb_check_for_dead_nodes(struct tevent_context *ev,
struct tevent_timer *te,
struct timeval t, void *private_data)
{
struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
int i;
/* send a keepalive to all other nodes, unless */
for (i=0;i<ctdb->num_nodes;i++) {
struct ctdb_node *node = ctdb->nodes[i];
if (node->flags & NODE_FLAGS_DELETED) {
continue;
}
if (node->pnn == ctdb->pnn) {
continue;
}
if (node->flags & NODE_FLAGS_DISCONNECTED) {
/* it might have come alive again */
if (node->rx_cnt != 0) {
ctdb_node_connected(node);
}
continue;
}
if (node->rx_cnt == 0) {
node->dead_count++;
} else {
node->dead_count = 0;
}
node->rx_cnt = 0;
if (node->dead_count >= ctdb->tunable.keepalive_limit) {
DEBUG(DEBUG_NOTICE,("dead count reached for node %u\n", node->pnn));
ctdb_node_dead(node);
ctdb_send_keepalive(ctdb, node->pnn);
/* maybe tell the transport layer to kill the
sockets as well?
*/
continue;
}
DEBUG(DEBUG_DEBUG,("sending keepalive to %u\n", node->pnn));
ctdb_send_keepalive(ctdb, node->pnn);
node->tx_cnt = 0;
}
tevent_add_timer(ctdb->ev, ctdb->keepalive_ctx,
timeval_current_ofs(ctdb->tunable.keepalive_interval, 0),
ctdb_check_for_dead_nodes, ctdb);
}
void ctdb_start_keepalive(struct ctdb_context *ctdb)
{
struct tevent_timer *te;
ctdb->keepalive_ctx = talloc_new(ctdb);
CTDB_NO_MEMORY_FATAL(ctdb, ctdb->keepalive_ctx);
te = tevent_add_timer(ctdb->ev, ctdb->keepalive_ctx,
timeval_current_ofs(ctdb->tunable.keepalive_interval, 0),
ctdb_check_for_dead_nodes, ctdb);
CTDB_NO_MEMORY_FATAL(ctdb, te);
DEBUG(DEBUG_NOTICE,("Keepalive monitoring has been started\n"));
if (ctdb->tunable.allow_mixed_versions == 1) {
DEBUG(DEBUG_WARNING,
("CTDB cluster with mixed versions configured\n"));
}
}
void ctdb_stop_keepalive(struct ctdb_context *ctdb)
{
talloc_free(ctdb->keepalive_ctx);
ctdb->keepalive_ctx = NULL;
}
void ctdb_request_keepalive(struct ctdb_context *ctdb,
struct ctdb_req_header *hdr)
{
struct ctdb_req_keepalive_old *c =
(struct ctdb_req_keepalive_old *)hdr;
uint32_t my_version = keepalive_version();
uint32_t my_uptime = keepalive_uptime(ctdb);
/* Don't check anything if mixed versions are allowed */
if (ctdb->tunable.allow_mixed_versions == 1) {
return;
}
if (hdr->length == sizeof(struct ctdb_req_header)) {
/* Old keepalive */
goto fail1;
}
if (c->version != my_version) {
if (c->uptime > my_uptime) {
goto fail2;
} else if (c->uptime == my_uptime) {
if (c->version > my_version) {
goto fail2;
}
}
}
return;
fail1:
DEBUG(DEBUG_ERR,
("Keepalive version missing from node %u\n", hdr->srcnode));
goto shutdown;
fail2:
DEBUG(DEBUG_ERR,
("Keepalive version mismatch 0x%08x != 0x%08x from node %u\n",
my_version, c->version, hdr->srcnode));
goto shutdown;
shutdown:
DEBUG(DEBUG_ERR,
("CTDB Cluster with mixed versions, cannot continue\n"));
ctdb_shutdown_sequence(ctdb, 0);
}