sam_hc_callback_register(3) [centos man page]
SAM_HC_CALLBACK_REGISTER(3) Corosync Cluster Engine Programmer's Manual SAM_HC_CALLBACK_REGISTER(3) 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 regulargly called and must return 0 if the process is functioning normally, or -1 if the process is executing abnor- mally. 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 inturrupted by a signal CS_ERR_NOT_SUPPORTED The requested protocol/functuality not supported CS_ERR_MESSAGE_ERROR Incorrect auth message received CS_ERR_NO_MEMORY Not enough memory to completed the requested task corosync Man Page 12/01/2009 SAM_HC_CALLBACK_REGISTER(3)
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SAM_REGISTER(3) Corosync Cluster Engine Programmer's Manual SAM_REGISTER(3) NAME
sam_rehister - Register component for health checking SYNOPSIS
#include <corosync/sam.h> cs_error_t sam_register (unsigned int *instance_id); DESCRIPTION
The sam_register function is used to register a process for healthchecking. If recovery policy is set to SAM_RECOVERY_POLICY_RESTART and recovery action will be taken, the new process instance will begin execution at the next code line after this function is called. This function can be called only once and SAM must be initialized by sam_initialize(3) function. The instance_id argument is a pointer to a value storing the current iteration instance. If this parameter is NULL, no instance_id is returned. and then, no instance_id will be returned. This value starts at 0 for the first iteration instance, and increases by 1 each time a recovery restart is executed. After reaching MAX_INT, the instance_id will reset to 0. The placement of this function is important because after it is called, the process id will change. After registration, event driven health checking is not running. RETURN VALUE
This call return CS_OK value if successful, otherwise and error is returned. ERRORS
CS_ERR_BAD_HANDLE health checking was not started by calling sam_start(3) function. CS_ERR_LIBRARY internal library call failed. This can be one of pipe creation or fork. It's possible to get more information from errno. SEE ALSO
sam_start(3), sam_initialize(3), sam_hc_callback_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 inturrupted by a signal CS_ERR_NOT_SUPPORTED The requested protocol/functuality not supported CS_ERR_MESSAGE_ERROR Incorrect auth message received CS_ERR_NO_MEMORY Not enough memory to completed the requested task corosync Man Page 12/01/2009 SAM_REGISTER(3)