SAM_HC_CALLBACK_REGISTER(3) Corosync Cluster Engine Programmer's Manual

NAME

sam_hc_callback_register - Register health check callback

SYNOPSIS

#include <corosync/sam.h>


cs_error_t sam_hc_callback_register (sam_hc_callback_t cb);

DESCRIPTION

The sam_hc_callback_register function is used to register a user
provided healthcheck callback. After calling of this function, the
SAM is switched from application driven healthchecking to event
driven healthchecking. In this mode, sam_hc_send(3) does not need to
be executed.


The parameter cb is callback function of type sam_hc_callback_t
defined as:

typedef int (*sam_hc_callback_t)(void);


This function will be regularly called and must return 0 if the
process is functioning normally, or -1 if the process is executing
abnormally. When -1 is returned, the SAM server execute the
registered recovery policy.


A value of NULL can be passed into this function to switch into
application driven healthchecking. cb to NULL.

RETURN VALUE

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

ERRORS

CS_ERR_BAD_HANDLE
SAM was not initialized and registered or health checking is
in running state

CS_ERR_LIBRARY
internal library call failed. This can occur during fork() or
pipe() system calls and the errno variable can be read to
retrieve more information.

SEE ALSO

sam_start(3), sam_stop(3), sam_hc_send(3), sam_register(3),

CS_ERR_TRY_AGAIN Resource temporarily unavailable

CS_ERR_INVALID_PARAM Invalid argument

CS_ERR_ACCESS Permission denied

CS_ERR_LIBRARY The connection failed

CS_ERR_INTERRUPT System call interrupted by a signal

CS_ERR_NOT_SUPPORTED The requested protocol/functionality not
supported

CS_ERR_MESSAGE_ERROR Incorrect auth message received

CS_ERR_NO_MEMORY Not enough memory to complete the requested task

corosync Man Page 12/01/2009 SAM_HC_CALLBACK_REGISTER(3)