No OneTemporary
Actions

Size

60 KB

Referenced Files

None

Subscribers

None

View Options

	diff --git a/src/config.h b/src/config.h
	index e531833..d44de3a 100644
	--- a/src/config.h
	+++ b/src/config.h
	@@ -1,210 +1,212 @@
	/*
	* Copyright (C) 2011 Jiaju Zhang <jjzhang@suse.de>
	* Copyright (C) 2013-2014 Philipp Marek <philipp.marek@linbit.com>
	*
	* 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 2.1 of the License, or (at your option) any later version.
	*
	* This software 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 library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#ifndef _CONFIG_H
	#define _CONFIG_H

	#include <stdint.h>
	#include "booth.h"
	#include "raft.h"
	#include "transport.h"


	/** @{ */
	/** Definitions for in-RAM data. */

	#define MAX_NODES 16
	#define TICKET_ALLOC 16



	struct ticket_config {
	/** \name Configuration items.
	* @{ */
	/** Name of ticket. */
	boothc_ticket name;

	/** How many seconds a term lasts (if not refreshed). */
	int term_duration;

	/** Network related timeouts. */
	int timeout;

	/** Retries before giving up. */
	int retries;

	/** If >0, time to wait for a site to get fenced.
	* The ticket may be acquired after that timespan by
	* another site. */
	int acquire_after; /* TODO: needed? */


	/* Program to ask whether it makes sense to
	* acquire the ticket */
	char *ext_verifier;

	/** Node weights. */
	int weight[MAX_NODES];
	/** @} */


	/** \name Runtime values.
	* @{ */
	/** Current state. */
	server_state_e state;

	/** When something has to be done */
	struct timeval next_cron;

	/** Current leader. This is effectively the log[] in Raft. */
	struct booth_site *leader;

	/** Is the ticket granted? */
	int is_granted;
	/** Timestamp of leadership expiration */
	time_t term_expires;
	/** End of election period */
	time_t election_end;
	struct booth_site *voted_for;


	/** Who the various sites vote for.
	* NO_OWNER = no vote yet. */
	struct booth_site *votes_for[MAX_NODES];
	/* bitmap */
	uint64_t votes_received;

	/** Last voting round that was seen. */
	uint32_t current_term;

	/** Do ticket updates whenever we get enough heartbeats.
	* But do that only once.
	* This is reset to 0 whenever we broadcast heartbeat and set
	* to 1 once enough acks are received.
	+ * Increased to 2 when the ticket is commited to the CIB (see
	+ * delay_commit).
	*/
	uint32_t ticket_updated;
	/** @} */


	/** */
	uint32_t commit_index;

	/** */
	uint32_t last_applied;
	uint32_t next_index[MAX_NODES];
	uint32_t match_index[MAX_NODES];


	/* if it is potentially dangerous to grant the ticket
	* immediately, then this is set to some point in time,
	* usually (now + term_duration + acquire_after)
	*/
	- time_t delay_grant;
	+ time_t delay_commit;

	/* if we expect some acks, then set this to the id of
	* the RPC which others will send us; it is cleared once all
	* replies were received
	*/
	uint32_t acks_expected;
	/* bitmask of servers which sent acks
	*/
	uint64_t acks_received;
	/* timestamp of the request, currently unused */
	time_t req_sent_at;

	/* don't log warnings unnecessarily
	*/
	int expect_more_rejects;
	/** \name Needed while proposals are being done.
	* @{ */
	/** Whom to vote for the next time.
	* Needed to push a ticket to someone else. */



	#if 0
	/** Bitmap of sites that acknowledge that state. */
	uint64_t proposal_acknowledges;

	/** When an incompletely acknowledged proposal gets done.
	* If all peers agree, that happens sooner.
	* See switch_state_to(). */
	struct timeval proposal_switch;

	/** Timestamp of proposal expiration. */
	time_t proposal_expires;

	#endif

	/** Number of send retries left.
	* Used on the new owner.
	* Starts at 0, counts up. */
	int retry_number;
	/** @} */
	};


	struct booth_config {
	char name[BOOTH_NAME_LEN];

	transport_layer_t proto;
	uint16_t port;

	/** Stores the OR of sites bitmasks. */
	uint64_t sites_bits;
	/** Stores the OR of all members' bitmasks. */
	uint64_t all_bits;

	char site_user[BOOTH_NAME_LEN];
	char site_group[BOOTH_NAME_LEN];
	char arb_user[BOOTH_NAME_LEN];
	char arb_group[BOOTH_NAME_LEN];
	uid_t uid;
	gid_t gid;

	int site_count;
	struct booth_site site[MAX_NODES];

	int ticket_count;
	int ticket_allocated;
	struct ticket_config *ticket;
	};


	extern struct booth_config *booth_conf;


	int read_config(const char *path);

	int check_config(int type);

	int find_site_by_name(unsigned char site, struct booth_site *node, int any_type);
	int find_site_by_id(uint32_t site_id, struct booth_site **node);

	const char *type_to_string(int type);


	#include <stdio.h>
	#define R(tk_) do { if (ANYDEBUG) printf("## %12s:%3d state %s, %d:%d, " \
	"leader %s, exp %s", __FILE__, __LINE__, \
	state_to_string(tk_->state), tk_->current_term, \
	tk_->commit_index, site_string(tk_->leader), ctime(&tk_->term_expires)); } while(0)


	#endif /* _CONFIG_H */
	diff --git a/src/inline-fn.h b/src/inline-fn.h
	index 67bd6d2..cf04b5a 100644
	--- a/src/inline-fn.h
	+++ b/src/inline-fn.h
	@@ -1,344 +1,344 @@
	/*
	* Copyright (C) 2013-2014 Philipp Marek <philipp.marek@linbit.com>
	*
	* 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 2.1 of the License, or (at your option) any later version.
	*
	* This software 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 library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#ifndef _INLINE_FN_H
	#define _INLINE_FN_H

	#include <time.h>
	#include <sys/time.h>
	#include <assert.h>
	#include <string.h>
	#include "config.h"
	#include "ticket.h"
	#include "transport.h"



	inline static uint32_t get_local_id(void)
	{
	return local ? local->site_id : -1;
	}


	inline static uint32_t get_node_id(struct booth_site *node)
	{
	return node ? node->site_id : NO_ONE;
	}


	inline static int term_time_left(const struct ticket_config *tk)
	{
	int left;

	left = tk->term_expires - time(NULL);
	return (left < 0) ? 0 : left;
	}


	/** Returns number of seconds left, if any. */
	inline static int leader_and_valid(const struct ticket_config *tk)
	{
	if (tk->leader != local)
	return 0;

	return term_time_left(tk);
	}


	/** Is this some leader? */
	inline static int is_owned(const struct ticket_config *tk)
	{
	return (tk->leader && tk->leader != no_leader);
	}


	static inline void init_header_bare(struct boothc_header *h) {
	h->magic = htonl(BOOTHC_MAGIC);
	h->version = htonl(BOOTHC_VERSION);
	h->from = htonl(local->site_id);
	h->iv = htonl(0);
	h->auth1 = htonl(0);
	h->auth2 = htonl(0);
	}

	static inline void init_header(struct boothc_header *h,
	int cmd, int options,
	int result, int reason, int data_len)
	{
	init_header_bare(h);
	h->length = htonl(data_len);
	h->cmd = htonl(cmd);
	h->options = htonl(options);
	h->result = htonl(result);
	h->reason = htonl(reason);
	}

	static inline void init_ticket_site_header(struct boothc_ticket_msg *msg, int cmd)
	{
	init_header(&msg->header, cmd, 0, 0, 0, sizeof(*msg));
	}

	static inline void init_ticket_msg(struct boothc_ticket_msg *msg,
	int cmd, int rv, int reason,
	struct ticket_config *tk)
	{
	assert(sizeof(msg->ticket.id) == sizeof(tk->name));

	init_header(&msg->header, cmd, 0, rv, reason, sizeof(*msg));

	if (!tk) {
	memset(&msg->ticket, 0, sizeof(msg->ticket));
	} else {
	memcpy(msg->ticket.id, tk->name, sizeof(msg->ticket.id));

	msg->ticket.leader = htonl(get_node_id(
	(tk->leader && tk->leader != no_leader) ? tk->leader : tk->voted_for));
	msg->ticket.term = htonl(tk->current_term);
	msg->ticket.term_valid_for = htonl(term_time_left(tk));

	msg->ticket.leader_commit = htonl(tk->commit_index);
	}
	}


	static inline struct booth_transport const *transport(void)
	{
	return booth_transport + booth_conf->proto;
	}


	static inline const char site_string(struct booth_site site)
	{
	return site ? site->addr_string : "NONE";
	}


	static inline const char ticket_leader_string(struct ticket_config tk)
	{
	return site_string(tk->leader);
	}


	static inline void disown_ticket(struct ticket_config *tk)
	{
	tk->leader = no_leader;
	tk->is_granted = 0;
	time(&tk->term_expires);
	}

	static inline int disown_if_expired(struct ticket_config *tk)
	{
	if (time(NULL) >= tk->term_expires \|\|
	!tk->leader) {
	disown_ticket(tk);
	return 1;
	}

	return 0;
	}



	/* We allow half of the uint32_t to be used;
	* half of that below, half of that above the current known "good" value.
	* 0 UINT32_MAX
	* \|--------------------------+----------------+------------\|
	* \| \| \|
	* \|--------+-------\| allowed range
	* \|
	* current commit index
	*
	* So, on overflow it looks like that:
	* UINT32_MAX 0
	* \|--------------------------+-----------\|\|---+------------\|
	* \| \| \|
	* \|--------+-------\| allowed range
	* \|
	* current commit index
	*
	* This should be possible by using the same datatype and relying
	* on the under/overflow semantics.
	*
	*
	* Having 30 bits available, and assuming an expire time of
	* one minute and a (high) commit index step of 64 == 2^6 (because
	* of weights), we get 2^24 minutes of range - which is ~750
	* years. "Should be enough for everybody."
	*/
	static inline int index_is_higher_than(uint32_t c_high, uint32_t c_low)
	{
	uint32_t diff;

	if (c_high == c_low)
	return 0;

	diff = c_high - c_low;
	if (diff < UINT32_MAX/4)
	return 1;

	diff = c_low - c_high;
	if (diff < UINT32_MAX/4)
	return 0;

	assert(!"commit index out of range - invalid");
	}


	static inline uint32_t index_max2(uint32_t a, uint32_t b)
	{
	return index_is_higher_than(a, b) ? a : b;
	}

	static inline uint32_t index_max3(uint32_t a, uint32_t b, uint32_t c)
	{
	return index_max2( index_max2(a, b), c);
	}


	static inline double timeval_to_float(struct timeval tv)
	{
	return tv.tv_sec + tv.tv_usec*(double)1.0e-6;
	}

	static inline int timeval_msec(struct timeval tv)
	{
	int m;

	m = tv.tv_usec / 1000;
	if (m >= 1000)
	m = 999;
	return m;
	}


	static inline int timeval_compare(struct timeval tv1, struct timeval tv2)
	{
	if (tv1.tv_sec < tv2.tv_sec)
	return -1;
	if (tv1.tv_sec > tv2.tv_sec)
	return +1;
	if (tv1.tv_usec < tv2.tv_usec)
	return -1;
	if (tv1.tv_usec > tv2.tv_usec)
	return +1;
	return 0;
	}


	static inline int timeval_in_past(struct timeval which)
	{
	struct timeval tv;

	gettimeofday(&tv, NULL);
	return timeval_compare(tv, which) > 0;
	}


	static inline time_t next_vote_starts_at(struct ticket_config *tk)
	{
	time_t half_exp, retries_needed, t;

	/* If not owner, don't renew. */
	if (tk->leader != local)
	return 0;

	/* Try to renew at half of expiry time. */
	half_exp = tk->term_expires - tk->term_duration/2;
	/* Also start renewal if we couldn't get
	* a few message retransmission in the alloted
	* expiry time. */
	retries_needed = tk->term_expires - tk->timeout * tk->retries/2;

	/* Return earlier timestamp. */
	t = min(half_exp, retries_needed);

	/* Return earlier timestamp if we need to delay the grant. */
	- if (tk->delay_grant > time(NULL))
	- t = min(tk->delay_grant, t);
	+ if (tk->delay_commit > time(NULL))
	+ t = min(tk->delay_commit, t);

	return t;
	}


	static inline int should_start_renewal(struct ticket_config *tk)
	{
	time_t now, when;

	when = next_vote_starts_at(tk);
	if (!when)
	return 0;

	time(&now);
	return when <= now;
	}

	static inline void expect_replies(struct ticket_config *tk,
	int reply_type)
	{
	tk->retry_number = 0;
	tk->acks_expected = reply_type;
	tk->acks_received = local->bitmask;
	tk->req_sent_at = time(NULL);
	tk->ticket_updated = 0;
	}

	static inline void no_resends(struct ticket_config *tk)
	{
	tk->retry_number = 0;
	tk->acks_expected = 0;
	tk->acks_received = 0;
	}

	static inline int send_heartbeat(struct ticket_config *tk)
	{
	expect_replies(tk, OP_HEARTBEAT);

	return ticket_broadcast(tk, OP_HEARTBEAT, RLT_SUCCESS, 0);
	}

	static inline struct booth_site my_vote(struct ticket_config tk)
	{
	return tk->votes_for[ local->index ];
	}


	static inline int count_bits(uint64_t val) {
	return __builtin_popcount(val);
	}

	static inline int majority_of_bits(struct ticket_config *tk, uint64_t val)
	{
	/* Use ">" to get majority decision, even for an even number
	* of participants. */
	return count_bits(val) * 2 >
	booth_conf->site_count;
	}


	static inline int all_replied(struct ticket_config *tk)
	{
	return !(tk->acks_received ^ booth_conf->all_bits);
	}

	static inline int all_sites_replied(struct ticket_config *tk)
	{
	return !((tk->acks_received & booth_conf->sites_bits) ^ booth_conf->sites_bits);
	}


	#endif
	diff --git a/src/raft.c b/src/raft.c
	index 07eadc0..09542ad 100644
	--- a/src/raft.c
	+++ b/src/raft.c
	@@ -1,883 +1,827 @@
	/*
	* Copyright (C) 2014 Philipp Marek <philipp.marek@linbit.com>
	*
	* 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 2.1 of the License, or (at your option) any later version.
	*
	* This software 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 library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <stdlib.h>
	#include <inttypes.h>
	#include <string.h>
	#include <errno.h>
	#include <arpa/inet.h>
	+#include <clplumbing/cl_random.h>
	#include "booth.h"
	#include "transport.h"
	#include "inline-fn.h"
	#include "config.h"
	#include "raft.h"
	#include "ticket.h"
	#include "log.h"



	inline static void clear_election(struct ticket_config *tk)
	{
	int i;
	struct booth_site *site;

	tk_log_debug("clear election");
	tk->votes_received = 0;
	foreach_node(i, site)
	tk->votes_for[site->index] = NULL;
	}


	inline static void record_vote(struct ticket_config *tk,
	struct booth_site *who,
	struct booth_site *vote)
	{
	tk_log_debug("site %s votes for %s",
	site_string(who),
	site_string(vote));

	if (!tk->votes_for[who->index]) {
	tk->votes_for[who->index] = vote;
	tk->votes_received \|= who->bitmask;
	} else {
	if (tk->votes_for[who->index] != vote)
	tk_log_warn("%s voted previously "
	"for %s and now wants to vote for %s (ignored)",
	site_string(who),
	site_string(tk->votes_for[who->index]),
	site_string(vote));
	}
	}


	static int cmp_msg_ticket(struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg)
	{
	if (tk->current_term != ntohl(msg->ticket.term)) {
	return tk->current_term - ntohl(msg->ticket.term);
	}
	/* compare commit_index only from the leader */
	if (sender == leader) {
	return tk->commit_index - ntohl(msg->ticket.leader_commit);
	}
	return 0;
	}

	static void update_term_from_msg(struct ticket_config *tk,
	struct boothc_ticket_msg *msg)
	{
	uint32_t i;


	i = ntohl(msg->ticket.term);
	/* if we failed to start the election, then accept the term
	* from the leader
	* */
	if (tk->state == ST_CANDIDATE) {
	tk->current_term = i;
	} else {
	tk->current_term = max(i, tk->current_term);
	}

	/* § 5.3 */
	i = ntohl(msg->ticket.leader_commit);
	tk->commit_index = max(i, tk->commit_index);
	}


	static void update_ticket_from_msg(struct ticket_config *tk,
	struct boothc_ticket_msg *msg)
	{
	int duration;

	duration = tk->term_duration;
	if (msg)
	duration = min(duration, ntohl(msg->ticket.term_valid_for));
	tk->term_expires = time(NULL) + duration;

	if (msg) {
	update_term_from_msg(tk, msg);
	}
	}


	static void become_follower(struct ticket_config *tk,
	struct boothc_ticket_msg *msg)
	{
	update_ticket_from_msg(tk, msg);
	tk->state = ST_FOLLOWER;
	- tk->delay_grant = 0;
	+ tk->delay_commit = 0;
	}


	struct booth_site majority_votes(struct ticket_config tk)
	{
	int i, n;
	struct booth_site *v;
	int count[MAX_NODES] = { 0, };


	for(i=0; i<booth_conf->site_count; i++) {
	v = tk->votes_for[i];
	if (!v)
	continue;

	n = v->index;
	count[n]++;
	tk_log_debug("Majority: %d %s wants %d %s => %d",
	i, site_string(&booth_conf->site[i]),
	n, site_string(v),
	count[n]);

	if (count[n]*2 <= booth_conf->site_count)
	continue;


	tk_log_debug("Majority reached: %d of %d for %s",
	count[n], booth_conf->site_count,
	site_string(v));
	return v;
	}

	return NULL;
	}


	static int newer_term(struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg,
	int in_election)
	{
	uint32_t term;

	term = ntohl(msg->ticket.term);
	/* §5.1 */
	if (term > tk->current_term) {
	tk->state = ST_FOLLOWER;
	if (!in_election) {
	tk->leader = leader;
	tk_log_info("from %s: higher term %d vs. %d, following %s",
	site_string(sender),
	term, tk->current_term,
	ticket_leader_string(tk));
	} else {
	tk->leader = no_leader;
	tk_log_debug("from %s: higher term %d vs. %d (election)",
	site_string(sender),
	term, tk->current_term);
	}

	tk->current_term = term;
	return 1;
	}

	return 0;
	}

	static int term_too_low(struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg)
	{
	uint32_t term;

	term = ntohl(msg->ticket.term);
	/* §5.1 */
	if (term < tk->current_term) {
	tk_log_info("sending reject to %s, its term too low "
	"(%d vs. %d)", site_string(sender),
	term, tk->current_term
	);
	send_reject(sender, tk, RLT_TERM_OUTDATED);
	return 1;
	}

	return 0;
	}




	/* For follower. */
	static int answer_HEARTBEAT (
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	uint32_t term;
	struct boothc_ticket_msg omsg;


	term = ntohl(msg->ticket.term);
	tk_log_debug("leader: %s, have %s; term %d vs %d",
	site_string(leader), ticket_leader_string(tk),
	term, tk->current_term);

	/* got heartbeat, no rejects expected anymore */
	tk->expect_more_rejects = 0;

	/* if we're candidate, it may be that we got a heartbeat from
	* a legitimate leader, so don't ignore a lower term
	*/
	if (tk->state != ST_CANDIDATE && term < tk->current_term) {
	tk_log_info("ignoring lower term %d vs. %d, from %s",
	term, tk->current_term,
	ticket_leader_string(tk));
	return 0;
	}

	/* Needed? */
	newer_term(tk, sender, leader, msg, 0);

	become_follower(tk, msg);
	/* Racy??? */
	assert(sender == leader \|\| !leader);

	tk->leader = leader;

	/* Ack the heartbeat (we comply). */
	init_ticket_msg(&omsg, OP_HEARTBEAT, RLT_SUCCESS, 0, tk);
	return booth_udp_send(sender, &omsg, sizeof(omsg));
	}


	static int process_UPDATE (
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	uint32_t term;


	term = ntohl(msg->ticket.term);
	tk_log_debug("leader: %s, have %s; term %d vs %d",
	site_string(leader), ticket_leader_string(tk),
	term, tk->current_term);

	/* No reject. (?) */
	if (term < tk->current_term) {
	tk_log_info("ignoring lower term %d vs. %d, from %s",
	term, tk->current_term,
	ticket_leader_string(tk));
	return 0;
	}

	update_ticket_from_msg(tk, msg);
	ticket_write(tk);

	/* run ticket_cron if the ticket expires */
	set_ticket_wakeup(tk);

	return 0;
	}

	static int process_REVOKE (
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	if (tk->leader != sender) {
	tk_log_error("%s wants to revoke ticket, "
	"but it is not granted there (ignoring)",
	site_string(sender));
	return 1;
	} else if (tk->state != ST_FOLLOWER) {
	tk_log_error("unexpected ticket revoke from %s "
	"(in state %s) (ignoring)",
	site_string(sender),
	state_to_string(tk->state));
	return 1;
	} else {
	tk_log_info("%s revokes ticket",
	site_string(tk->leader));
	reset_ticket(tk);
	ticket_write(tk);
	}

	return 0;
	}


	-/* is it safe to commit the grant?
	- * if we didn't hear from all sites on the initial grant, we may
	- * need to delay the commit
	- *
	- * TODO: investigate possibility to devise from history whether a
	- * missing site could be holding a ticket or not
	- */
	-static int ticket_dangerous(struct ticket_config *tk)
	-{
	- if (!tk->delay_grant)
	- return 0;
	-
	- if (tk->delay_grant < time(NULL) \|\|
	- all_sites_replied(tk)) {
	- tk->delay_grant = 0;
	- return 0;
	- }
	-
	- return 1;
	-}
	-
	-
	-/* update the ticket on the leader, write it to the CIB, and
	- send out the update message to others with the new expiry
	- time
	-*/
	-int leader_update_ticket(struct ticket_config *tk)
	-{
	- struct boothc_ticket_msg msg;
	- int rv = 0;
	-
	- if( tk->ticket_updated )
	- return 0;
	-
	- tk->ticket_updated = 1;
	- tk->term_expires = time(NULL) + tk->term_duration;
	-
	- if (!ticket_dangerous(tk)) {
	- ticket_write(tk);
	- init_ticket_msg(&msg, OP_UPDATE, RLT_SUCCESS, 0, tk);
	- rv = transport()->broadcast(&msg, sizeof(msg));
	- } else {
	- tk_log_info("delaying ticket commit to CIB until %s "
	- "(or all sites are reached)",
	- ctime(&tk->delay_grant));
	- }
	-
	- return rv;
	-}
	-
	/* For leader. */
	static int process_HEARTBEAT(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	uint32_t term;

	term = ntohl(msg->ticket.term);

	if (newer_term(tk, sender, leader, msg, 0)) {
	/* unexpected higher term */
	tk_log_warn("got higher term from %s (%d vs. %d)",
	site_string(sender),
	term, tk->current_term);
	return 0;
	}

	/* Don't send a reject. */
	if (term < tk->current_term) {
	/* Doesn't know what he's talking about - perhaps
	* doesn't receive our packets? */
	tk_log_warn("unexpected term "
	"from %s (%d vs. %d) (ignoring)",
	site_string(sender),
	term, tk->current_term);
	return 0;
	}


	if (term == tk->current_term &&
	leader == tk->leader) {

	- if (majority_of_bits(tk, tk->acks_received) &&
	- !ticket_dangerous(tk)) {
	+ if (majority_of_bits(tk, tk->acks_received)) {
	/* OK, at least half of the nodes are reachable;
	* Update the ticket and send update messages out
	*/
	return leader_update_ticket(tk);
	}
	}

	return 0;
	}


	-void leader_elected(
	- struct ticket_config *tk,
	- struct booth_site *new_leader
	- )
	-{
	- if (new_leader) {
	- tk->leader = new_leader;
	-
	- tk->term_expires = time(NULL) + tk->term_duration;
	- tk->election_end = 0;
	- tk->voted_for = NULL;
	-
	- if (new_leader == local) {
	- tk_log_info("the ticket is granted here");
	- tk->commit_index++;
	- tk->state = ST_LEADER;
	- send_heartbeat(tk);
	- ticket_activate_timeout(tk);
	- } else {
	- tk_log_info("ticket granted at %s",
	- site_string(new_leader));
	- become_follower(tk, NULL);
	- set_ticket_wakeup(tk);
	- }
	- }
	-}
	-
	-
	static int process_VOTE_FOR(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	if (term_too_low(tk, sender, leader, msg))
	return 0;

	if (newer_term(tk, sender, leader, msg, 0)) {
	clear_election(tk);
	}


	/* leader wants to step down? */
	if (leader == no_leader && sender == tk->leader &&
	(tk->state == ST_FOLLOWER \|\| tk->state == ST_CANDIDATE)) {
	tk_log_info("%s wants to give the ticket away",
	site_string(tk->leader));
	return new_round(tk, OR_STEPDOWN);
	}

	record_vote(tk, sender, leader);


	if (tk->state != ST_CANDIDATE) {
	/* lost candidate status, somebody rejected our proposal */
	return 0;
	}


	/* only if all voted can we take the ticket now, otherwise
	* wait for timeout in ticket_cron */
	if (!tk->acks_expected) {
	/* §5.2 */
	leader_elected(tk, majority_votes(tk));
	}

	return 0;
	}


	static int process_REJECTED(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	uint32_t rv;

	rv = ntohl(msg->header.result);

	if (tk->state == ST_CANDIDATE &&
	rv == RLT_TERM_OUTDATED) {
	tk_log_warn("ticket outdated (term %d), granted at %s",
	ntohl(msg->ticket.term),
	site_string(leader)
	);
	tk->leader = leader;
	tk->expect_more_rejects = 1;
	become_follower(tk, msg);
	return 0;
	}

	if (tk->state == ST_CANDIDATE &&
	rv == RLT_TERM_STILL_VALID) {
	tk_log_warn("ticket was granted at %s "
	"(and we didn't know)",
	site_string(leader));
	tk->leader = leader;
	tk->expect_more_rejects = 1;
	become_follower(tk, msg);
	return 0;
	}

	if (tk->state == ST_CANDIDATE &&
	rv == RLT_YOU_OUTDATED) {
	tk->leader = leader;
	tk->expect_more_rejects = 1;
	if (leader && leader != no_leader) {
	tk_log_warn("our ticket is outdated, granted at %s",
	site_string(leader));
	become_follower(tk, msg);
	} else {
	tk_log_warn("our ticket is outdated and revoked");
	update_ticket_from_msg(tk, msg);
	tk->state = ST_INIT;
	}
	return 0;
	}

	if (!tk->expect_more_rejects) {
	tk_log_warn("from %s: in state %s, got %s (unexpected reject)",
	site_string(sender),
	state_to_string(tk->state),
	state_to_string(rv));
	}

	return 0;
	}


	static int ticket_seems_ok(struct ticket_config *tk)
	{
	int time_left;

	time_left = term_time_left(tk);
	if (!time_left)
	return 0; /* quite sure */
	if (tk->state == ST_CANDIDATE)
	return 0; /* in state of flux */
	if (tk->state == ST_LEADER)
	return 1; /* quite sure */
	if (tk->state == ST_FOLLOWER &&
	time_left >= tk->term_duration/3)
	return 1; /* almost quite sure */
	return 0;
	}


	static int test_reason(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	int reason;

	reason = ntohl(msg->header.reason);
	if (reason == OR_TKT_LOST) {
	if (tk->state == ST_INIT) {
	tk_log_warn("%s claims that the ticket is lost, "
	"but it's in %s state (reject sent)",
	site_string(sender),
	state_to_string(tk->state)
	);
	return RLT_YOU_OUTDATED;
	}
	if (ticket_seems_ok(tk)) {
	tk_log_warn("%s claims that the ticket is lost, "
	"but it is ok here (reject sent)",
	site_string(sender));
	return RLT_TERM_STILL_VALID;
	}
	}
	return 0;
	}


	/* §5.2 */
	static int answer_REQ_VOTE(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	uint32_t term;
	int valid;
	struct boothc_ticket_msg omsg;
	cmd_result_t inappr_reason;

	inappr_reason = test_reason(tk, sender, leader, msg);
	if (inappr_reason)
	return send_reject(sender, tk, inappr_reason);

	term = ntohl(msg->ticket.term);
	/* Important: Ignore duplicated packets! */
	valid = term_time_left(tk);
	if (valid &&
	term == tk->current_term &&
	sender == tk->leader) {
	tk_log_debug("Duplicate OP_VOTE_FOR ignored.");
	return 0;
	}

	if (valid) {
	tk_log_warn("election rejected, term still valid for %ds", valid);
	return send_reject(sender, tk, RLT_TERM_STILL_VALID);
	}

	if (term_too_low(tk, sender, leader, msg))
	return 0;

	/* if it's a newer term or ... */
	if (newer_term(tk, sender, leader, msg, 1)) {
	clear_election(tk);
	goto vote_for_sender;
	}


	/* ... we didn't vote yet, then vote for the sender */
	/* §5.2, §5.4 */
	if (!tk->voted_for) {
	vote_for_sender:
	tk->voted_for = sender;
	record_vote(tk, sender, leader);
	}


	init_ticket_msg(&omsg, OP_VOTE_FOR, RLT_SUCCESS, 0, tk);
	omsg.ticket.leader = htonl(get_node_id(tk->voted_for));
	return booth_udp_send(sender, &omsg, sizeof(omsg));
	}


	int new_election(struct ticket_config *tk,
	struct booth_site *preference, int update_term, cmd_reason_t reason)
	{
	struct booth_site *new_leader;
	time_t now;
	static cmd_reason_t last_reason;


	time(&now);
	tk_log_debug("start new election?, now=%" PRIi64 ", end %" PRIi64,
	(int64_t)now, (int64_t)(tk->election_end));
	if (now <= tk->election_end)
	return 0;


	/* §5.2 */
	/* If there was _no_ answer, don't keep incrementing the term number
	* indefinitely. If there was no peer, there'll probably be no one
	* listening now either. However, we don't know if we were
	* invoked due to a timeout (caller does).
	*/
	if (update_term)
	tk->current_term++;

	tk->term_expires = 0;
	tk->election_end = now + tk->timeout;

	tk_log_info("starting new election (term=%d, until %s)",
	tk->current_term, ctime(&tk->election_end));
	clear_election(tk);

	if(preference)
	new_leader = preference;
	else
	new_leader = (local->type == SITE) ? local : NULL;
	record_vote(tk, local, new_leader);
	tk->voted_for = new_leader;

	tk->state = ST_CANDIDATE;

	/* some callers may want just to repeat on timeout */
	if (reason == OR_AGAIN) {
	reason = last_reason;
	} else {
	last_reason = reason;
	}

	expect_replies(tk, OP_VOTE_FOR);
	ticket_broadcast(tk, OP_REQ_VOTE, RLT_SUCCESS, reason);
	ticket_activate_timeout(tk);
	return 0;
	}


	+int new_round(struct ticket_config *tk, cmd_reason_t reason)
	+{
	+ int rv = 0;
	+ struct timespec delay;
	+
	+ disown_ticket(tk);
	+
	+ /* New vote round; §5.2 */
	+ if (local->type == SITE) {
	+ /* delay the next election start for up to 200ms */
	+ delay.tv_sec = 0;
	+ delay.tv_nsec = 1000000L * (long)cl_rand_from_interval(0, 200);
	+ nanosleep(&delay, NULL);
	+
	+ rv = new_election(tk, NULL, 1, reason);
	+ ticket_write(tk);
	+ }
	+
	+ return rv;
	+}
	+
	+
	/* we were a leader and somebody says that they have a more up
	* to date ticket
	* there was probably connectivity loss
	* tricky
	*/
	static int leader_handle_newer_ticket(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	if (leader == no_leader \|\| !leader \|\| leader == local) {
	/* at least nobody else owns the ticket */
	/* it is not kosher to update from their copy, but since
	* they don't own the ticket, nothing bad can happen
	*/
	update_term_from_msg(tk, msg);
	/* get the ticket again, if we can
	*/
	tk_log_info("trying to reclaim the ticket");
	return acquire_ticket(tk, OR_REACQUIRE);
	}

	/* eek, two leaders, split brain */
	/* normally shouldn't happen; run election */
	tk_log_error("from %s: ticket granted at %s! (revoking locally)",
	site_string(sender),
	site_string(leader)
	);
	return new_round(tk, OR_SPLIT);
	}

	/* reply to STATUS */
	static int process_MY_INDEX (
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	int i;
	int rv;

	if (!msg->ticket.term_valid_for) {
	/* ticket not valid */
	return 0;
	}

	i = cmp_msg_ticket(tk, sender, leader, msg);

	if (i > 0) {
	/* let them know about our newer ticket */
	send_msg(OP_MY_INDEX, tk, sender);
	if (tk->state == ST_LEADER) {
	- tk_log_info("sending update to %s",
	+ tk_log_info("sending ticket update to %s",
	site_string(sender));
	return send_msg(OP_UPDATE, tk, sender);
	}
	}

	/* they have a newer ticket, trouble if we're already leader
	* for it */
	if (i < 0 && tk->state == ST_LEADER) {
	tk_log_warn("from %s: more up to date ticket at %s",
	site_string(sender),
	site_string(leader)
	);
	return leader_handle_newer_ticket(tk, sender, leader, msg);
	}

	update_ticket_from_msg(tk, msg);
	tk->leader = leader;
	if (leader == local) {
	rv = test_external_prog(tk, 1);
	if (!rv) {
	/* if we were the leader but we rebooted in the
	* meantime; try to get the ticket again
	*/
	tk->state = ST_LEADER;
	tk_log_info("trying to reclaim the ticket");
	rv = send_heartbeat(tk);
	ticket_activate_timeout(tk);
	}
	return rv;
	} else {
	if (!leader \|\| leader == no_leader) {
	tk_log_info("ticket is not granted");
	tk->state = ST_INIT;
	} else {
	tk_log_info("ticket granted at %s (says %s)",
	site_string(leader),
	site_string(sender));
	tk->state = ST_FOLLOWER;
	}
	set_ticket_wakeup(tk);
	}
	return 0;
	}


	int raft_answer(
	struct ticket_config *tk,
	struct booth_site *from,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	int cmd;
	int rv;

	rv = 0;
	cmd = ntohl(msg->header.cmd);

	tk_log_debug("got message %s from %s",
	state_to_string(cmd),
	site_string(from));


	switch (cmd) {
	case OP_REQ_VOTE:
	rv = answer_REQ_VOTE(tk, from, leader, msg);
	break;
	case OP_VOTE_FOR:
	rv = process_VOTE_FOR(tk, from, leader, msg);
	break;
	case OP_HEARTBEAT:
	if (tk->leader == local &&
	tk->state == ST_LEADER)
	rv = process_HEARTBEAT(tk, from, leader, msg);
	else if (tk->leader != local &&
	(tk->state == ST_INIT \|\|tk->state == ST_FOLLOWER \|\|
	tk->state == ST_CANDIDATE))
	rv = answer_HEARTBEAT(tk, from, leader, msg);
	else {
	tk_log_warn("unexpected message %s, from %s",
	state_to_string(cmd),
	site_string(from));
	rv = -EINVAL;
	}
	break;
	case OP_UPDATE:
	if (tk->leader != local && tk->state == ST_FOLLOWER) {
	rv = process_UPDATE(tk, from, leader, msg);
	} else {
	tk_log_warn("unexpected message %s, from %s",
	state_to_string(cmd),
	site_string(from));
	rv = -EINVAL;
	}
	break;
	case OP_REJECTED:
	rv = process_REJECTED(tk, from, leader, msg);
	break;
	case OP_REVOKE:
	rv = process_REVOKE(tk, from, leader, msg);
	break;
	case OP_MY_INDEX:
	rv = process_MY_INDEX(tk, from, leader, msg);
	break;
	case OP_STATUS:
	rv = send_msg(OP_MY_INDEX, tk, from);
	break;
	default:
	tk_log_error("unknown message %s, from %s",
	state_to_string(cmd), site_string(from));
	rv = -EINVAL;
	}
	return rv;
	}
	diff --git a/src/raft.h b/src/raft.h
	index 3a547e3..a8afdf6 100644
	--- a/src/raft.h
	+++ b/src/raft.h
	@@ -1,48 +1,45 @@
	/*
	* Copyright (C) 2014 Philipp Marek <philipp.marek@linbit.com>
	*
	* 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 2.1 of the License, or (at your option) any later version.
	*
	* This software 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 library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#ifndef _RAFT_H
	#define _RAFT_H

	#include "booth.h"

	typedef enum {
	ST_INIT = CHAR2CONST('I', 'n', 'i', 't'),
	ST_FOLLOWER = CHAR2CONST('F', 'l', 'l', 'w'),
	ST_CANDIDATE = CHAR2CONST('C', 'n', 'd', 'i'),
	ST_LEADER = CHAR2CONST('L', 'e', 'a', 'd'),
	} server_state_e;

	struct ticket_config;

	-int leader_update_ticket(struct ticket_config *tk);
	-void leader_elected(struct ticket_config *tk,
	- struct booth_site *new_leader);
	-
	struct booth_site majority_votes(struct ticket_config tk);

	int raft_answer(struct ticket_config *tk,
	struct booth_site *from,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg);

	int new_election(struct ticket_config *tk,
	struct booth_site *new_leader, int update_term, cmd_reason_t reason);
	+int new_round(struct ticket_config *tk, cmd_reason_t reason);


	#endif /* _RAFT_H */
	diff --git a/src/ticket.c b/src/ticket.c
	index 6b7eb79..778dc1c 100644
	--- a/src/ticket.c
	+++ b/src/ticket.c
	@@ -1,803 +1,868 @@
	/*
	* Copyright (C) 2011 Jiaju Zhang <jjzhang@suse.de>
	* Copyright (C) 2013-2014 Philipp Marek <philipp.marek@linbit.com>
	*
	* 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 2.1 of the License, or (at your option) any later version.
	*
	* This software 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 library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <stdlib.h>
	#include <string.h>
	#include <errno.h>
	#include <arpa/inet.h>
	#include <inttypes.h>
	#include <stdio.h>
	#include <assert.h>
	#include <time.h>
	-#include <clplumbing/cl_random.h>
	#include "ticket.h"
	#include "config.h"
	#include "pacemaker.h"
	#include "inline-fn.h"
	#include "log.h"
	#include "booth.h"
	#include "raft.h"
	#include "handler.h"

	#define TK_LINE 256


	/* Untrusted input, must fit (incl. \0) in a buffer of max chars. */
	int check_max_len_valid(const char *s, int max)
	{
	int i;
	for(i=0; i<max; i++)
	if (s[i] == 0)
	return 1;
	return 0;
	}

	int find_ticket_by_name(const char ticket, struct ticket_config *found)
	{
	int i;

	if (found)
	*found = NULL;

	for (i = 0; i < booth_conf->ticket_count; i++) {
	if (!strcmp(booth_conf->ticket[i].name, ticket)) {
	if (found)
	*found = booth_conf->ticket + i;
	return 1;
	}
	}

	return 0;
	}


	int check_ticket(char ticket, struct ticket_config *found)
	{
	if (found)
	*found = NULL;
	if (!booth_conf)
	return 0;

	if (!check_max_len_valid(ticket, sizeof(booth_conf->ticket[0].name)))
	return 0;
	return find_ticket_by_name(ticket, found);
	}

	int check_site(char site, int is_local)
	{
	struct booth_site *node;

	if (!check_max_len_valid(site, sizeof(node->addr_string)))
	return 0;

	if (find_site_by_name(site, &node, 0)) {
	*is_local = node->local;
	return 1;
	}

	return 0;
	}


	int ticket_write(struct ticket_config *tk)
	{
	if (local->type != SITE)
	return -EINVAL;

	disown_if_expired(tk);

	if (tk->leader == local) {
	pcmk_handler.grant_ticket(tk);
	} else {
	pcmk_handler.revoke_ticket(tk);
	}

	return 0;
	}


	/* Ask an external program whether getting the ticket
	* makes sense.
	* Eg. if the services have a failcount of INFINITY,
	* we can't serve here anyway. */
	int test_external_prog(struct ticket_config *tk,
	int start_election)
	{
	int rv;

	rv = run_handler(tk, tk->ext_verifier, 1);
	if (rv) {
	tk_log_warn("we are not allowed to acquire ticket");

	/* Give it to somebody else.
	* Just send a VOTE_FOR message, so the
	* others can start elections. */
	if (leader_and_valid(tk)) {
	disown_ticket(tk);
	if (start_election) {
	ticket_broadcast(tk, OP_VOTE_FOR, RLT_SUCCESS, OR_LOCAL_FAIL);
	}
	}
	}

	return rv;
	}


	/* Try to acquire a ticket
	* Could be manual grant or after ticket loss
	*/
	int acquire_ticket(struct ticket_config *tk, cmd_reason_t reason)
	{
	if (test_external_prog(tk, 0))
	return RLT_EXT_FAILED;

	return new_election(tk, local, 1, reason);
	}


	/** Try to get the ticket for the local site.
	* */
	int do_grant_ticket(struct ticket_config *tk, int options)
	{
	int rv;

	tk_log_info("granting ticket");

	if (tk->leader == local)
	return RLT_SUCCESS;
	if (is_owned(tk))
	return RLT_OVERGRANT;

	- tk->delay_grant = time(NULL) +
	+ tk->delay_commit = time(NULL) +
	tk->term_duration + tk->acquire_after;

	if (options & OPT_IMMEDIATE) {
	tk_log_warn("granting ticket immediately! If there are "
	"unreachable sites, _hope_ you are sure that they don't "
	"have the ticket!");
	- tk->delay_grant = 0;
	+ tk->delay_commit = 0;
	}

	rv = acquire_ticket(tk, OR_ADMIN);
	if (rv)
	- tk->delay_grant = 0;
	+ tk->delay_commit = 0;
	return rv;
	}


	/** Ticket revoke.
	* Only to be started from the leader. */
	int do_revoke_ticket(struct ticket_config *tk)
	{
	tk_log_info("revoking ticket");

	reset_ticket(tk);
	ticket_write(tk);
	return ticket_broadcast(tk, OP_REVOKE, RLT_SUCCESS, OR_ADMIN);
	}


	int list_ticket(char *pdata, unsigned int len)
	{
	struct ticket_config *tk;
	char timeout_str[64];
	char pending_str[64];
	char data, cp;
	int i, alloc;

	*pdata = NULL;
	*len = 0;

	alloc = 256 +
	booth_conf->ticket_count * (BOOTH_NAME_LEN * 2 + 128);
	data = malloc(alloc);
	if (!data)
	return -ENOMEM;

	cp = data;
	foreach_ticket(i, tk) {
	if (tk->term_expires != 0)
	strftime(timeout_str, sizeof(timeout_str), "%F %T",
	localtime(&tk->term_expires));
	else
	strcpy(timeout_str, "INF");

	- if (tk->leader == local && tk->delay_grant > time(NULL)) {
	- strcpy(pending_str, " (pending until ");
	- strftime(pending_str + strlen(" (pending until "),
	- sizeof(pending_str) - strlen(" (pending until ") - 1,
	- "%F %T", localtime(&tk->delay_grant));
	+ if (tk->leader == local && tk->delay_commit > time(NULL)) {
	+ strcpy(pending_str, " (commit pending until ");
	+ strftime(pending_str + strlen(" (commit pending until "),
	+ sizeof(pending_str) - strlen(" (commit pending until ") - 1,
	+ "%F %T", localtime(&tk->delay_commit));
	strcat(pending_str, ")");
	} else
	*pending_str = '\0';

	cp += snprintf(cp,
	alloc - (cp - data),
	"ticket: %s, leader: %s, expires: %s, commit: %d%s\n",
	tk->name,
	ticket_leader_string(tk),
	timeout_str,
	tk->commit_index,
	pending_str);

	if (alloc - (cp - data) <= 0)
	return -ENOMEM;
	}

	*pdata = data;
	*len = cp - data;

	return 0;
	}

	void reset_ticket(struct ticket_config *tk)
	{
	disown_ticket(tk);
	tk->state = ST_INIT;
	tk->voted_for = NULL;
	}


	void reacquire_ticket(struct ticket_config *tk)
	{
	int valid;

	valid = (tk->term_expires >= time(NULL));
	if (!valid) {
	tk_log_warn("granted here, but not valid "
	"anymore, will try to reacquire");
	}
	if (tk->leader != local) {
	if (tk->leader && tk->leader != no_leader) {
	tk_log_error("granted here, but belongs to "
	"site %s, that's really too bad (will try to reacquire)",
	site_string(tk->leader));
	} else {
	tk_log_warn("granted here, but we're "
	"not recorded as a grantee (will try to reacquire)");
	}
	tk->leader = local;
	}
	if (!test_external_prog(tk, 1)) {
	/* if the ticket is valid, try with
	* the heartbeat (otherwise we may get a
	* rejected election if the ticket is still valid
	* with other servers)
	* else it's preferable to acquire the
	* ticket through new elections
	*/
	if (valid) {
	tk->state = ST_LEADER;
	send_heartbeat(tk);
	ticket_activate_timeout(tk);
	} else {
	acquire_ticket(tk, OR_REACQUIRE);
	}
	}
	}

	int setup_ticket(void)
	{
	struct ticket_config *tk;
	int i;

	foreach_ticket(i, tk) {
	reset_ticket(tk);

	if (local->type == SITE) {
	pcmk_handler.load_ticket(tk);
	}


	if (tk->is_granted) {
	reacquire_ticket(tk);
	} else {
	/* otherwise, query status */
	tk_log_info("broadcasting state query");
	ticket_broadcast(tk, OP_STATUS, RLT_SUCCESS, 0);
	}
	}

	return 0;
	}


	int ticket_answer_list(int fd, struct boothc_ticket_msg *msg)
	{
	char *data;
	int olen, rv;
	struct boothc_header hdr;

	rv = list_ticket(&data, &olen);
	if (rv < 0)
	return rv;

	init_header(&hdr, CMR_LIST, 0, RLT_SUCCESS, 0, sizeof(hdr) + olen);

	return send_header_plus(fd, &hdr, data, olen);
	}


	int ticket_answer_grant(int fd, struct boothc_ticket_msg *msg)
	{
	int rv;
	struct ticket_config *tk;


	if (!check_ticket(msg->ticket.id, &tk)) {
	log_warn("client asked to grant unknown ticket %s",
	msg->ticket.id);
	rv = RLT_INVALID_ARG;
	goto reply;
	}

	if (is_owned(tk)) {
	log_warn("client wants to grant an (already granted!) ticket %s",
	msg->ticket.id);
	rv = RLT_OVERGRANT;
	goto reply;
	}

	rv = do_grant_ticket(tk, ntohl(msg->header.options));

	reply:
	init_header(&msg->header, CMR_GRANT, 0, rv ?: RLT_ASYNC, 0, sizeof(*msg));
	return send_ticket_msg(fd, msg);
	}


	int ticket_answer_revoke(int fd, struct boothc_ticket_msg *msg)
	{
	int rv;
	struct ticket_config *tk;

	if (!check_ticket(msg->ticket.id, &tk)) {
	log_warn("client wants to revoke an unknown ticket %s",
	msg->ticket.id);
	rv = RLT_INVALID_ARG;
	goto reply;
	}

	if (!is_owned(tk)) {
	log_info("client wants to revoke a free ticket %s",
	msg->ticket.id);
	rv = RLT_TICKET_IDLE;
	goto reply;
	}

	if (tk->leader != local) {
	log_info("the ticket %s is not granted here, "
	"redirect to %s",
	msg->ticket.id, ticket_leader_string(tk));
	rv = RLT_REDIRECT;
	goto reply;
	}

	rv = do_revoke_ticket(tk);
	if (rv == 0)
	rv = RLT_ASYNC;

	reply:
	init_ticket_msg(msg, CMR_REVOKE, rv, 0, tk);
	return send_ticket_msg(fd, msg);
	}


	int ticket_broadcast(struct ticket_config *tk,
	cmd_request_t cmd, cmd_result_t res, cmd_reason_t reason)
	{
	struct boothc_ticket_msg msg;

	init_ticket_msg(&msg, cmd, res, reason, tk);
	tk_log_debug("broadcasting '%s' (term=%d, valid=%d)",
	state_to_string(cmd),
	ntohl(msg.ticket.term),
	ntohl(msg.ticket.term_valid_for));

	return transport()->broadcast(&msg, sizeof(msg));
	}


	-int new_round(struct ticket_config *tk, cmd_reason_t reason)
	+/* is it safe to commit the grant?
	+ * if we didn't hear from all sites on the initial grant, we may
	+ * need to delay the commit
	+ *
	+ * TODO: investigate possibility to devise from history whether a
	+ * missing site could be holding a ticket or not
	+ */
	+static int ticket_dangerous(struct ticket_config *tk)
	+{
	+ if (!tk->delay_commit)
	+ return 0;
	+
	+ if (tk->delay_commit <= time(NULL) \|\|
	+ all_sites_replied(tk)) {
	+ tk->delay_commit = 0;
	+ return 0;
	+ }
	+
	+ return 1;
	+}
	+
	+
	+/* update the ticket on the leader, write it to the CIB, and
	+ send out the update message to others with the new expiry
	+ time
	+*/
	+int leader_update_ticket(struct ticket_config *tk)
	{
	+ struct boothc_ticket_msg msg;
	int rv = 0;
	- struct timespec delay;

	- disown_ticket(tk);
	+ if (tk->ticket_updated >= 2)
	+ return 0;
	+
	+ if (tk->ticket_updated < 1) {
	+ tk->ticket_updated = 1;
	+ tk->term_expires = time(NULL) + tk->term_duration;

	- /* New vote round; §5.2 */
	- if (local->type == SITE) {
	- /* delay the next election start for up to 200ms */
	- delay.tv_sec = 0;
	- delay.tv_nsec = 1000000L * (long)cl_rand_from_interval(0, 200);
	- nanosleep(&delay, NULL);
	+ tk_log_debug("broadcasting ticket update");
	+ init_ticket_msg(&msg, OP_UPDATE, RLT_SUCCESS, 0, tk);
	+ rv = transport()->broadcast(&msg, sizeof(msg));
	+ }

	- rv = new_election(tk, NULL, 1, reason);
	- ticket_write(tk);
	+ if (tk->ticket_updated < 2) {
	+ if (!ticket_dangerous(tk)) {
	+ tk->ticket_updated = 2;
	+ ticket_write(tk);
	+ } else {
	+ /* log just once, on the first retry */
	+ if (tk->retry_number <= 1)
	+ tk_log_info("delaying ticket commit to CIB for %ds "
	+ "(or all sites are reached)",
	+ (int)(tk->delay_commit - time(NULL)));
	+ }
	}

	return rv;
	}


	+void leader_elected(
	+ struct ticket_config *tk,
	+ struct booth_site *new_leader
	+ )
	+{
	+ if (new_leader == local) {
	+ tk->leader = new_leader;
	+
	+ tk->term_expires = time(NULL) + tk->term_duration;
	+ tk->election_end = 0;
	+ tk->voted_for = NULL;
	+
	+ tk_log_info("granted successfully here");
	+ tk->commit_index++;
	+ tk->state = ST_LEADER;
	+ send_heartbeat(tk);
	+ ticket_activate_timeout(tk);
	+ } else if (new_leader && new_leader != no_leader) {
	+ tk_log_error("%s is a new leader, strange",
	+ site_string(new_leader));
	+ }
	+}
	+
	+
	static void log_lost_servers(struct ticket_config *tk)
	{
	struct booth_site *n;
	int i;

	- if (tk->retry_number != 1)
	+ if (tk->retry_number > 1)
	/* log those that we couldn't reach, but do
	* that only on the first retry
	*/
	return;

	for (i = 0; i < booth_conf->site_count; i++) {
	n = booth_conf->site + i;
	if (!(tk->acks_received & n->bitmask)) {
	tk_log_warn("%s %s didn't acknowledge our request, "
	"will retry %d times",
	(n->type == ARBITRATOR ? "arbitrator" : "site"),
	site_string(n),
	tk->retries);
	}
	}
	}

	static void resend_msg(struct ticket_config *tk)
	{
	struct booth_site *n;
	int i;

	if (!(tk->acks_received ^ local->bitmask)) {
	ticket_broadcast(tk, tk->acks_expected, RLT_SUCCESS, 0);
	} else {
	for (i = 0; i < booth_conf->site_count; i++) {
	n = booth_conf->site + i;
	if (!(tk->acks_received & n->bitmask)) {
	tk_log_debug("resending %s to %s",
	state_to_string(tk->acks_expected),
	site_string(n)
	);
	send_msg(tk->acks_expected, tk, n);
	}
	}
	}
	}

	static void handle_resends(struct ticket_config *tk)
	{
	int ack_cnt;

	tk->retry_number ++;
	if (!majority_of_bits(tk, tk->acks_received)) {
	ack_cnt = count_bits(tk->acks_received) - 1;
	if (!ack_cnt) {
	tk_log_warn("no answers to heartbeat (try #%d), "
	"we are alone",
	tk->retry_number);
	} else {
	tk_log_warn("not enough answers to heartbeat (try #%d): "
	"only got %d answers",
	tk->retry_number,
	ack_cnt);
	}
	} else {
	log_lost_servers(tk);
	/* we have the majority, update the ticket, at
	* least the local copy if we're still not
	* allowed to commit
	*/
	leader_update_ticket(tk);
	}

	if (tk->retry_number <= tk->retries) {
	resend_msg(tk);
	ticket_activate_timeout(tk);
	} else {
	tk_log_debug("giving up on sending retries");
	no_resends(tk);
	set_ticket_wakeup(tk);
	}
	}

	static void ticket_cron(struct ticket_config *tk)
	{
	time_t now;
	struct booth_site *new_leader;

	now = time(NULL);


	/* Has an owner, has an expiry date, and expiry date in the past?
	* Losing the ticket must happen in _every_ state. */
	if (tk->term_expires &&
	is_owned(tk) &&
	now >= tk->term_expires) {

	if (tk->leader != local) {
	tk_log_warn("lost at %s", site_string(tk->leader));
	} else {
	tk_log_warn("lost majority (revoking locally)");
	}

	/* Couldn't renew in time - ticket lost. */
	new_round(tk, OR_TKT_LOST);
	return;
	}

	switch(tk->state) {
	case ST_INIT:
	/* init state, nothing to do */
	break;

	case ST_FOLLOWER:
	/* nothing here either, ticket loss is caught earlier
	* */
	break;

	case ST_CANDIDATE:
	/* §5.2 */
	/* not everybody answered, but if we have majority... */
	new_leader = majority_votes(tk);
	if (new_leader) {
	leader_elected(tk, new_leader);
	} else if (now > tk->election_end) {
	/* This is previous election timed out */
	tk_log_info("election timed out");
	new_election(tk, NULL, 0, OR_AGAIN);
	}
	break;

	case ST_LEADER:
	/* timeout or ticket renewal? */
	if (tk->acks_expected) {
	handle_resends(tk);
	} else {
	/* this is ticket renewal, run local test */
	if (!test_external_prog(tk, 1)) {
	send_heartbeat(tk);
	ticket_activate_timeout(tk);
	}
	}
	break;

	default:
	break;
	}
	}


	void process_tickets(void)
	{
	struct ticket_config *tk;
	int i;
	struct timeval now;
	float sec_until;

	gettimeofday(&now, NULL);

	foreach_ticket(i, tk) {
	sec_until = timeval_to_float(tk->next_cron) - timeval_to_float(now);
	if (0)
	tk_log_debug("next cron %" PRIx64 ".%03d, "
	"now %" PRIx64 "%03d, in %f",
	(uint64_t)tk->next_cron.tv_sec, timeval_msec(tk->next_cron),
	(uint64_t)now.tv_sec, timeval_msec(now),
	sec_until);
	if (sec_until > 0.0)
	continue;

	tk_log_debug("ticket cron");


	/* Set next value, handler may override.
	* This should already be handled via the state logic;
	* but to be on the safe side the renew repetition is
	* duplicated here, too. */
	set_ticket_wakeup(tk);

	ticket_cron(tk);
	}
	}



	void tickets_log_info(void)
	{
	struct ticket_config *tk;
	int i;

	foreach_ticket(i, tk) {
	tk_log_info("state '%s' "
	"commit index %d "
	"leader %s "
	"expires %-24.24s",
	state_to_string(tk->state),
	tk->commit_index,
	ticket_leader_string(tk),
	ctime(&tk->term_expires));
	}
	}


	static void update_acks(
	struct ticket_config *tk,
	struct booth_site *sender,
	struct booth_site *leader,
	struct boothc_ticket_msg *msg
	)
	{
	uint32_t cmd;

	cmd = ntohl(msg->header.cmd);
	if (tk->acks_expected != cmd)
	return;

	/* got an ack! */
	tk->acks_received \|= sender->bitmask;

	tk_log_debug("got ACK from %s, %d/%d agree.",
	site_string(sender),
	count_bits(tk->acks_received),
	booth_conf->site_count);

	+ if (tk->delay_commit && all_sites_replied(tk)) {
	+ tk->delay_commit = 0;
	+ }
	+
	if (all_replied(tk)) {
	no_resends(tk);
	set_ticket_wakeup(tk);
	}
	}

	/* UDP message receiver. */
	int message_recv(struct boothc_ticket_msg *msg, int msglen)
	{
	uint32_t from;
	struct booth_site *source;
	struct ticket_config *tk;
	struct booth_site *leader;
	uint32_t leader_u;


	if (check_boothc_header(&msg->header, sizeof(*msg)) < 0 \|\|
	msglen != sizeof(*msg)) {
	log_error("message receive error");
	return -1;
	}

	from = ntohl(msg->header.from);
	if (!find_site_by_id(from, &source) \|\| !source) {
	log_error("unknown sender: %08x", from);
	return -1;
	}

	if (!check_ticket(msg->ticket.id, &tk)) {
	log_warn("got invalid ticket name %s from %s",
	msg->ticket.id, site_string(source));
	return -EINVAL;
	}


	leader_u = ntohl(msg->ticket.leader);
	if (!find_site_by_id(leader_u, &leader)) {
	tk_log_error("message with unknown leader %u received", leader_u);
	return -EINVAL;
	}

	update_acks(tk, source, leader, msg);

	return raft_answer(tk, source, leader, msg);
	}


	void set_ticket_wakeup(struct ticket_config *tk)
	{
	struct timeval tv, now;

	/* At least every hour, perhaps sooner. */
	ticket_next_cron_in(tk, 3600);
	gettimeofday(&now, NULL);

	switch (tk->state) {
	case ST_LEADER:
	assert(tk->leader == local);

	tv = now;
	tv.tv_sec = next_vote_starts_at(tk);

	/* If timestamp is in the past, look again in one second. */
	if (timeval_compare(tv, now) <= 0)
	tv.tv_sec = now.tv_sec + 1;

	ticket_next_cron_at(tk, tv);
	break;

	case ST_CANDIDATE:
	assert(tk->election_end);
	ticket_next_cron_at_coarse(tk, tk->election_end);
	break;

	case ST_INIT:
	case ST_FOLLOWER:
	/* If there is (or should be) some owner, check on it later on.
	* If no one is interested - don't care. */
	if (is_owned(tk) &&
	(local->type == SITE))
	ticket_next_cron_at_coarse(tk,
	tk->term_expires + tk->acquire_after);
	break;

	default:
	tk_log_error("unknown ticket state: %d", tk->state);
	}

	if (ANYDEBUG) {
	float sec_until;
	gettimeofday(&now, NULL);
	sec_until = timeval_to_float(tk->next_cron) - timeval_to_float(now);
	tk_log_debug("set ticket wakeup in %f", sec_until);
	}
	}



	/* Given a state (in host byte order), return a human-readable (char*).
	* An array is used so that multiple states can be printed in a single printf(). */
	char *state_to_string(uint32_t state_ho)
	{
	union mu { cmd_request_t s; char c[5]; };
	static union mu cache[6] = { { 0 } }, *cur;
	static int current = 0;

	current ++;
	if (current >= sizeof(cache)/sizeof(cache[0]))
	current = 0;

	cur = cache + current;

	cur->s = htonl(state_ho);
	/* Shouldn't be necessary, union array is initialized with zeroes, and
	* these bytes never get written. */
	cur->c[4] = 0;
	return cur->c;
	}


	int send_reject(struct booth_site dest, struct ticket_config tk, cmd_result_t code)
	{
	struct boothc_ticket_msg msg;

	init_ticket_msg(&msg, OP_REJECTED, code, 0, tk);
	return booth_udp_send(dest, &msg, sizeof(msg));
	}

	int send_msg (
	int cmd,
	struct ticket_config *tk,
	struct booth_site *dest
	)
	{
	struct boothc_ticket_msg msg;

	if (cmd == OP_MY_INDEX) {
	tk_log_info("sending status to %s",
	site_string(dest));
	}
	init_ticket_msg(&msg, cmd, RLT_SUCCESS, 0, tk);
	return booth_udp_send(dest, &msg, sizeof(msg));
	}
	diff --git a/src/ticket.h b/src/ticket.h
	index 15e0645..fbe6bcb 100644
	--- a/src/ticket.h
	+++ b/src/ticket.h
	@@ -1,109 +1,111 @@
	/*
	* Copyright (C) 2011 Jiaju Zhang <jjzhang@suse.de>
	* Copyright (C) 2013-2014 Philipp Marek <philipp.marek@linbit.com>
	*
	* 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 2.1 of the License, or (at your option) any later version.
	*
	* This software 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 library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#ifndef _TICKET_H
	#define _TICKET_H

	#include <time.h>
	#include <sys/time.h>
	#include <math.h>

	#include "config.h"
	#include "log.h"

	#define DEFAULT_TICKET_EXPIRY 600
	#define DEFAULT_TICKET_TIMEOUT 5
	#define DEFAULT_RETRIES 10


	#define foreach_ticket(i_,t_) for(i=0; (t_=booth_conf->ticket+i, i<booth_conf->ticket_count); i++)
	#define foreach_node(i_,n_) for(i=0; (n_=booth_conf->site+i, i<booth_conf->site_count); i++)


	int check_ticket(char ticket, struct ticket_config *tc);
	int check_site(char site, int local);
	int grant_ticket(struct ticket_config *ticket);
	int revoke_ticket(struct ticket_config *ticket);
	int list_ticket(char *pdata, unsigned int len);

	int message_recv(struct boothc_ticket_msg *msg, int msglen);
	void reset_ticket(struct ticket_config *tk);
	void reacquire_ticket(struct ticket_config *tk);
	int setup_ticket(void);
	int check_max_len_valid(const char *s, int max);

	int do_grant_ticket(struct ticket_config *ticket, int options);
	int do_revoke_ticket(struct ticket_config *tk);

	int find_ticket_by_name(const char ticket, struct ticket_config *found);

	void set_ticket_wakeup(struct ticket_config *tk);

	int test_external_prog(struct ticket_config *tk, int start_election);
	int acquire_ticket(struct ticket_config *tk, cmd_reason_t reason);
	-int new_round(struct ticket_config *tk, cmd_reason_t reason);

	int ticket_answer_list(int fd, struct boothc_ticket_msg *msg);
	int ticket_answer_grant(int fd, struct boothc_ticket_msg *msg);
	int ticket_answer_revoke(int fd, struct boothc_ticket_msg *msg);

	int ticket_broadcast_proposed_state(struct ticket_config *tk, cmd_request_t state);

	int ticket_write(struct ticket_config *tk);

	void process_tickets(void);
	void tickets_log_info(void);
	char *state_to_string(uint32_t state_ho);
	int send_reject(struct booth_site dest, struct ticket_config tk, cmd_result_t code);
	int send_msg (int cmd, struct ticket_config tk, struct booth_site dest);
	int ticket_broadcast(struct ticket_config *tk, cmd_request_t cmd, cmd_result_t res, cmd_reason_t reason);

	+int leader_update_ticket(struct ticket_config *tk);
	+void leader_elected(struct ticket_config *tk,
	+ struct booth_site *new_leader);

	static inline void ticket_next_cron_at(struct ticket_config *tk, struct timeval when)
	{
	tk->next_cron = when;
	}

	static inline void ticket_next_cron_at_coarse(struct ticket_config *tk, time_t when)
	{
	tk->next_cron.tv_sec = when;
	tk->next_cron.tv_usec = 0;
	}

	static inline void ticket_next_cron_in(struct ticket_config *tk, float seconds)
	{
	struct timeval tv;

	gettimeofday(&tv, NULL);
	tv.tv_sec += trunc(seconds);
	tv.tv_usec += (seconds - trunc(seconds)) * 1e6;

	ticket_next_cron_at(tk, tv);
	}


	static inline void ticket_activate_timeout(struct ticket_config *tk)
	{
	/* TODO: increase timeout when no answers */
	tk_log_debug("activate ticket timeout");
	ticket_next_cron_in(tk, tk->timeout);
	}


	#endif /* _TICKET_H */

File Metadata

Mime Type: text/x-diff
Expires: Sat, Jan 25, 7:01 AM (1 d, 19 h)
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 1321220
Default Alt Text: (60 KB)

No OneTemporaryActions

View Options

File Metadata

Event Timeline

No OneTemporary
Actions