election.c File Reference

#include <crm_internal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <crm/msg_xml.h>
#include <crm/common/xml.h>
#include <crm/common/mainloop.h>
#include <crm/cluster/internal.h>
#include <crm/cluster/election_internal.h>
#include <crm/crm.h>

Include dependency graph for election.c:

Go to the source code of this file.

Macros
#define	STORM_INTERVAL   2 /* in seconds */
#define	LOSS_DAMPEN   2 /* in seconds */

Functions
enum election_result	election_state (const election_t *e)
	Get current state of an election. More...
election_t *	election_init (const char *name, const char *uname, guint period_ms, GSourceFunc cb)
	Create a new election object. More...
void	election_remove (election_t *e, const char *uname)
	Disregard any previous vote by specified peer. More...
void	election_reset (election_t *e)
	Stop election timer and disregard all votes. More...
void	election_fini (election_t *e)
	Free an election object. More...
void	election_timeout_stop (election_t *e)
	Stop an election's timer, if running. More...
void	election_timeout_set_period (election_t *e, guint period)
	Change an election's timeout (restarting timer if running) More...
void	election_vote (election_t *e)
	Start a new election by offering local node's candidacy. More...
bool	election_check (election_t *e)
	Check whether local node has won an election. More...
enum election_result	election_count_vote (election_t *e, const xmlNode *message, bool can_win)
	Process an election message (vote or no-vote) from a peer. More...
void	election_clear_dampening (election_t *e)
	Reset any election dampening currently in effect. More...

Variables
struct election_s	__attribute__

Macro Definition Documentation

LOSS_DAMPEN

#define LOSS_DAMPEN   2 /* in seconds */

Definition at line 399 of file election.c.

STORM_INTERVAL

#define STORM_INTERVAL   2 /* in seconds */

Definition at line 23 of file election.c.

Function Documentation

election_check()

bool election_check

(

election_t *

e

)

Check whether local node has won an election.

If all known peers have sent no-vote messages, stop the election timer, set the election state to won, and call any registered win callback.

Parameters

[in,out]

e

Election object

Returns

TRUE if local node has won, FALSE otherwise

Note

If all known peers have sent no-vote messages, but the election owner does not call this function, the election will not be won (and the callback will not be called) until the election times out.

This should be called when election_count_vote() returns election_in_progress.

Definition at line 343 of file election.c.

election_clear_dampening()

void election_clear_dampening

(

election_t *

e

)

Reset any election dampening currently in effect.

Parameters

[in,out]

e

Election object to clear

Definition at line 724 of file election.c.

election_count_vote()

enum election_result election_count_vote	(	election_t *	e,
		const xmlNode *	message,
		bool	can_win
	)

Process an election message (vote or no-vote) from a peer.

Parameters

[in,out]	e	Election object
[in]	message	Election message XML from peer
[in]	can_win	Whether local node is eligible to win

Returns

Election state after new vote is considered

Note

If the peer message is a vote, and we prefer the peer to win, this will send a no-vote reply to the peer.

The situations "we lost to this vote" from "this is a late no-vote after we've already lost" both return election_lost. If a caller needs to distinguish them, it should save the current state before calling this function, and then compare the result.

Definition at line 534 of file election.c.

election_fini()

void election_fini

(

election_t *

e

)

Free an election object.

Free all memory associated with an election object, stopping its election timer (if running).

Parameters

[in,out]

e

Election object

Definition at line 165 of file election.c.

election_init()

election_t* election_init	(	const char *	name,
		const char *	uname,
		guint	period_ms,
		GSourceFunc	cb
	)

Create a new election object.

Every node that wishes to participate in an election must create an election object. Typically, this should be done once, at start-up. A caller should only create a single election object.

Parameters

[in]	name	Label for election (for logging)
[in]	uname	Local node's name
[in]	period_ms	How long to wait for all peers to vote
[in]	cb	Function to call if local node wins election

Returns

Newly allocated election object on success, NULL on error

Note

The caller is responsible for freeing the returned value using election_fini().

Definition at line 89 of file election.c.

election_remove()

void election_remove	(	election_t *	e,
		const char *	uname
	)

Disregard any previous vote by specified peer.

This discards any recorded vote from a specified peer. Election users should call this whenever a voting peer becomes inactive.

Parameters

[in,out]	e	Election object
[in]	uname	Name of peer to disregard

Definition at line 129 of file election.c.

election_reset()

void election_reset

(

election_t *

e

)

Stop election timer and disregard all votes.

Parameters

[in,out]

e

Election object

Definition at line 143 of file election.c.

election_state()

enum election_result election_state

(

const election_t *

e

)

Get current state of an election.

Parameters

[in]

e

Election object

Returns

Current state of

Definition at line 67 of file election.c.

election_timeout_set_period()

void election_timeout_set_period	(	election_t *	e,
		guint	period
	)

Change an election's timeout (restarting timer if running)

Parameters

[in,out]	e	Election object
[in]	period	New timeout

Definition at line 205 of file election.c.

election_timeout_stop()

void election_timeout_stop

(

election_t *

e

)

Stop an election's timer, if running.

Parameters

[in,out]

e

Election object

Definition at line 191 of file election.c.

election_vote()

void election_vote

(

election_t *

e

)

Start a new election by offering local node's candidacy.

Broadcast a "vote" election message containing the local node's ID, (incremented) election counter, and uptime, and start the election timer.

Parameters

[in,out]

e

Election object

Note

Any nodes agreeing to the candidacy will send a "no-vote" reply, and if all active peers do so, or if the election times out, the local node wins the election. (If we lose to any peer vote, we will stop the timer, so a timeout means we did not lose – either some peer did not vote, or we did not call election_check() in time.)

Definition at line 290 of file election.c.

Variable Documentation

__attribute__

struct pcmk__cpg_msg_s __attribute__