corosync/man/sam_initialize.3

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.TH "SAM_INITIALIZE" 3 "21/05/2010" "corosync Man Page" "Corosync Cluster Engine Programmer's Manual"

.SH NAME
.P
sam_initialize \- Initialize health checking

.SH SYNOPSIS
.P
\fB#include <corosync/sam.h>\fR

.P
\fBcs_error_t sam_initialize (int\fR \fItime_interval\fR\fB, sam_recovery_policy_t \fIrecovery_policy\fR);\fR

.SH DESCRIPTION
.P
The \fBsam_initialize\fR function is used to initialize health checking of a process.

.P
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.

.P
The \fItime_interval\fR parameter is a timeout in milliseconds before taking
recovery action after having not received a healthcheck.

If \fItime_interval\fR 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.

.P
The \fIrecovery_policy\fR is defined as type:

.nf
  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_CONFDB = 0x10,
  } sam_recovery_policy_t;
.fi

.P
where

.TP
SAM_RECOVERY_POLICY_QUIT
on failure, the process will terminate.
.TP
SAM_RECOVERY_POLICY_RESTART
on failure, the process will restart.
.TP
SAM_RECOVERY_POLICY_QUORUM
is not policy. Used only as flag meaning quorum integration
.TP
SAM_RECOVERY_POLICY_QUORUM_QUIT
same as \fISAM_RECOVERY_POLICY_QUIT\fR but \fBsam_start (3)\fR will block until corosync becomes
quorate and process will be terminated if quorum is lost.
.TP
SAM_RECOVERY_POLICY_QUORUM_RESTART
same as \fISAM_RECOVERY_POLICY_RESTART\fR but \fBsam_start (3)\fR will block until corosync becomes
quorate and process will be restarted if quorum is lost.
.TP
SAM_RECOVERY_POLICY_CONFDB
is not policy. Used only as flag meaning confdb integration. It can be used with all previous policies.

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

.SH RETURN VALUE
.P
This call return CS_OK value if successful, otherwise and error is returned.

.SH ERRORS
.TP
CS_ERR_BAD_HANDLE
can happened in case of double initialization.
.TP
CS_ERR_INVALID_PARAM
\fIrecovery_policy\fR has invalid value.

.SH "SEE ALSO"
.BR sam_register (3),
.BR sam_start (3),
.BR sam_hc_callback_register (3)