See rte_site_role_policy.h. Moved unchanged from RBC_GP's ab_gp_site_role.c and the generic part of ab_gp_standby_policy.c (ADR-040 step 1); only the names changed. More...

#include "rte/redundancy/site_role/rte_site_role_policy.h"

Include dependency graph for rte_site_role_policy.c:

Functions
static bool	peer_answering (const rte_site_role_input_t *in)
static bool	pair_ready_to_promote (const rte_site_role_input_t *in)
rte_site_role_decision_t	rte_site_role_decide (const rte_site_role_input_t *in)
	Decides this cycle's role action. Rules are evaluated in this order and the first that applies wins:
const char *	rte_site_role_reason_text (rte_site_role_reason_t reason)
const char *	rte_site_role_reason_token (rte_site_role_reason_t reason)
bool	rte_site_role_standby_sync_due (bool sync_enabled, bool is_online, bool link_up, bool healthy, uint32_t cycle, uint32_t last_try)
	Whether ONLINE should attempt the pre-commit standby sync this cycle.
bool	rte_site_role_standby_data_stale (bool sync_enabled, bool is_online, bool have_snapshot, uint32_t cycle, uint32_t last_rx_cycle)
	Whether STANDBY's held snapshot is stale and must be dropped (STANDBY goes cold).
bool	rte_site_role_takeover_allowed (bool is_online, bool own_faulted, bool peer_unresponsive, bool confirmed, uint32_t cycle, uint32_t confirm_cycle)
	Whether a STANDBY channel may promote itself because its counterpart stopped responding. Silence alone never promotes: the dispatcher must have confirmed, within RTE_SITE_ROLE_TAKEOVER_CONFIRM_VALID_CYCLES, that the other site is not ONLINE.
bool	rte_site_role_both_standby_tiebreak (uint32_t both_standby_cycles, bool is_west, bool sibling_online)
	Negotiation tie-break for "both sites STANDBY": a channel whose A/B sibling is already ONLINE joins it at once; otherwise WEST promotes after RTE_SITE_ROLE_BOTH_STANDBY_CYCLES. Both sites compute the same answer from the same link, so this is a negotiation outcome, not a unilateral promotion.

Detailed Description

See rte_site_role_policy.h. Moved unchanged from RBC_GP's ab_gp_site_role.c and the generic part of ab_gp_standby_policy.c (ADR-040 step 1); only the names changed.

Definition in file rte_site_role_policy.c.

Function Documentation

◆ peer_answering()

bool peer_answering ( const rte_site_role_input_t * in )

static

The counterpart answered within the last 2 cycles.

Definition at line 9 of file rte_site_role_policy.c.

◆ pair_ready_to_promote()

bool pair_ready_to_promote ( const rte_site_role_input_t * in )

static

The A/B pair may promote: this channel is ready and its sibling is ONLINE, ready, or not there.

Definition at line 15 of file rte_site_role_policy.c.

◆ rte_site_role_decide()

rte_site_role_decision_t rte_site_role_decide ( const rte_site_role_input_t * in )

Decides this cycle's role action. Rules are evaluated in this order and the first that applies wins:

own FAULTED and counterpart FAULTED: RENEGOTIATE.
this channel is STANDBY, healthy, counterpart FAULTED: PROMOTE (PEER_FAULTED).
own FAULTED, counterpart healthy and holding an ONLINE snapshot: DEMOTE (RECOVERED).
STANDBY, counterpart silent, dispatcher confirmation valid: PROMOTE (DISPATCHER_CONFIRMED).
ONLINE and the counterpart, answering within 2 cycles, is ONLINE too: DEMOTE (YIELD_TO_TAKEOVER) if this channel was cut off while ONLINE, otherwise ALARM (DUAL_ONLINE).
STANDBY, link up, counterpart answering within 2 cycles and not ONLINE for RTE_SITE_ROLE_BOTH_STANDBY_CYCLES cycles (or 1 cycle when the A/B sibling is already ONLINE): PROMOTE (BOTH_STANDBY_WEST / _SIBLING).
STANDBY, A/B sibling ONLINE, own link view unusable and counterpart not verifiably ONLINE: follow the sibling after 2 cycles, PROMOTE (BOTH_STANDBY_SIBLING).

A promotion is only carried out when this channel is ready AND its A/B sibling is ONLINE already, or confirms it is ready, or cannot be reached (single channel). Otherwise the answer is WAIT.

Parameters

in	facts; must not be NULL

Returns: the decision; both_standby_cycles must be stored by the caller

Definition at line 20 of file rte_site_role_policy.c.

◆ rte_site_role_reason_text()

const char * rte_site_role_reason_text ( rte_site_role_reason_t reason )

Returns: a short text for a reason, for logs.

Definition at line 101 of file rte_site_role_policy.c.

◆ rte_site_role_reason_token()

const char * rte_site_role_reason_token ( rte_site_role_reason_t reason )

Returns: a one-word token (no spaces) for a reason, for the status frame.

Definition at line 141 of file rte_site_role_policy.c.

◆ rte_site_role_standby_sync_due()

bool rte_site_role_standby_sync_due	(	bool	sync_enabled,
		bool	is_online,
		bool	link_up,
		bool	healthy,
		uint32_t	cycle,
		uint32_t	last_try )

Whether ONLINE should attempt the pre-commit standby sync this cycle.

Parameters

sync_enabled	true when standby_mode is warm or hot
is_online	this channel is ONLINE
link_up	the inter-site link is open
healthy	STANDBY answered the last sync
cycle	current cycle number
last_try	cycle of the last sync attempt made while unhealthy

Returns: true if a sync should be sent now

Definition at line 181 of file rte_site_role_policy.c.

◆ rte_site_role_standby_data_stale()

bool rte_site_role_standby_data_stale	(	bool	sync_enabled,
		bool	is_online,
		bool	have_snapshot,
		uint32_t	cycle,
		uint32_t	last_rx_cycle )

Whether STANDBY's held snapshot is stale and must be dropped (STANDBY goes cold).

Returns: true if the snapshot has been silent for more than RTE_SITE_ROLE_STANDBY_DATA_TIMEOUT_CYCLES, or the cycle counter restarted since it arrived

Definition at line 202 of file rte_site_role_policy.c.

◆ rte_site_role_takeover_allowed()

bool rte_site_role_takeover_allowed	(	bool	is_online,
		bool	own_faulted,
		bool	peer_unresponsive,
		bool	confirmed,
		uint32_t	cycle,
		uint32_t	confirm_cycle )

Whether a STANDBY channel may promote itself because its counterpart stopped responding. Silence alone never promotes: the dispatcher must have confirmed, within RTE_SITE_ROLE_TAKEOVER_CONFIRM_VALID_CYCLES, that the other site is not ONLINE.

Definition at line 216 of file rte_site_role_policy.c.

◆ rte_site_role_both_standby_tiebreak()

bool rte_site_role_both_standby_tiebreak	(	uint32_t	both_standby_cycles,
		bool	is_west,
		bool	sibling_online )

Negotiation tie-break for "both sites STANDBY": a channel whose A/B sibling is already ONLINE joins it at once; otherwise WEST promotes after RTE_SITE_ROLE_BOTH_STANDBY_CYCLES. Both sites compute the same answer from the same link, so this is a negotiation outcome, not a unilateral promotion.

Definition at line 229 of file rte_site_role_policy.c.

Functions