Tribblix: manual page: sam

SAM_INITIALIZE(3) Corosync Cluster Engine Programmer's Manual

NAME

sam_initialize - Initialize health checking

SYNOPSIS

#include <corosync/sam.h>

cs_error_t sam_initialize (int time_interval, sam_recovery_policy_t
recovery_policy);

DESCRIPTION

The sam_initialize function is used to initialize health checking of
a process.

Application can have only one instance of SAM. This function must be
called before any other of SAM functions. It is recommended to
initialize before the process begins any process initialization.

The time_interval parameter is a timeout in milliseconds before
taking recovery action after having not received a healthcheck.

If time_interval parameter is zero, there is no time limit and no
healthcheck must be sent by the process. In this operational mode, a
process failure will continue to execute the recovery policy.

The recovery_policy is defined as type:

typedef enum {
SAM_RECOVERY_POLICY_QUIT = 1,
SAM_RECOVERY_POLICY_RESTART = 2,
SAM_RECOVERY_POLICY_QUORUM = 0x08,
SAM_RECOVERY_POLICY_QUORUM_QUIT = SAM_RECOVERY_POLICY_QUORUM | SAM_RECOVERY_POLICY_QUIT,
SAM_RECOVERY_POLICY_QUORUM_RESTART = SAM_RECOVERY_POLICY_QUORUM | SAM_RECOVERY_POLICY_RESTART,
SAM_RECOVERY_POLICY_CMAP = 0x10,
SAM_RECOVERY_POLICY_CONFDB = 0x10,
} sam_recovery_policy_t;

where

SAM_RECOVERY_POLICY_QUIT
on failure, the process will terminate.

SAM_RECOVERY_POLICY_RESTART
on failure, the process will restart.

SAM_RECOVERY_POLICY_QUORUM
is not policy. Used only as flag meaning quorum integration

SAM_RECOVERY_POLICY_QUORUM_QUIT
same as SAM_RECOVERY_POLICY_QUIT but sam_start (3) will block
until corosync becomes quorate and process will be terminated
if quorum is lost.

SAM_RECOVERY_POLICY_QUORUM_RESTART
same as SAM_RECOVERY_POLICY_RESTART but sam_start (3) will
block until corosync becomes quorate and process will be
restarted if quorum is lost.

SAM_RECOVERY_POLICY_CMAP
is not policy. Used only as flag meaning cmap integration. It
can be used with all previous policies. For backward
compatibility, SAM_RECOVERY_POLICY_CONFDB with same meaning as
SAM_RECOVERY_POLICY_CMAP is also provided.

To perform event driven healthchecking, sam_register(3) and
sam_start(3) functions must called. Event driven healthchecking
causes the duplicate standby process running the SAM serve rto
periodically request healthchecks from the active process.

RETURN VALUE

This call return CS_OK value if successful, otherwise and error is
returned.

ERRORS

CS_ERR_BAD_HANDLE
can happened in case of double initialization.

CS_ERR_INVALID_PARAM
recovery_policy has invalid value.

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

ERRORS

SEE ALSO