sam_hc_callback_register - Register health check callback
#include <corosync/sam.h>
cs_error_t sam_hc_callback_register (sam_hc_callback_t cb);
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.
This call return CS_OK value if successful, otherwise and error is returned.
- 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.
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