NAME

       quorum_model_initialize - Create a new connection to the Quorum service

SYNOPSIS

       #include <corosync/quorum.h>

       cs_error_t  quorum_model_initialize(quorum_handle_t  *handle,  quorum_model_t  model, quorum_model_data_t
       *model_data, uint32_t *quorum_type,void *context);

DESCRIPTION

       The quorum_model_initialize function is an enhanced way to initialize a connection to the quorum API.

       Each application may have several connections to the  quorum  API.   Each  application  uses  the  handle
       argument  to  uniquely identify the connection.  The handle argument is then used in other function calls
       to identify the connection to be used for communication with the quorum service.

       The model is used to explicitly choose set of callbacks and internal  parameters.  Currently  two  models
       QUORUM_MODEL_V0  and  QUORUM_MODEL_V1 are defined.  QUORUM_MODEL_V0 exists only for compatibility reasons
       with  quorum_initialize(3)  function  and  it  is  not  recommended  to  be  used  as  an  argument   for
       quorum_model_initialize(3).

       The Following description is focused only on QUORUM_MODEL_V1 model.

       Every  time  the voting configuration changes (eg a node joins or leave the cluster) or the quorum status
       changes the quorum callback is called.  The quorum callback function is described by the  following  type
       definitions:

       typedef void (*quorum_v1_quorum_notification_fn_t) (
               quorum_handle_t handle,
               uint32_t quorate,
               struct quorum_ring_id ring_id,
               uint32_t member_list_entries,
               const uint32_t *member_list
       );

       Also  every  time  when  membership configuration changes (eg a node joins or leave the cluster) the node
       list change callback is called before the quorum callback.  The node list  change  callback  function  is
       described by the following type definitions:

       typedef void (*quorum_v1_nodelist_notification_fn_t) (
               quorum_handle_t handle,
               struct quorum_ring_id ring_id,
               uint32_t member_list_entries,
               const uint32_t *member_list,
               uint32_t joined_list_entries,
               const uint32_t *joined_list,
               uint32_t left_list_entries,
               const uint32_t *left_list
       );

       The model_data argument for QUORUM_MODEL_V1 is of the type:

       typedef struct {
               quorum_model_t model;
               quorum_v1_quorum_notification_fn_t quorum_notify_fn;
               quorum_v1_nodelist_notification_fn_t nodelist_notify_fn;
       } quorum_model_v1_data_t;

       It's  not required (nor recommended) to set model field in the structure. It is also fine if only some of
       notification callbacks are used (only these events will be delivered then).

       The quorum_type argument is set to:

       #define QUORUM_FREE     0
       #define QUORUM_SET      1

       QUORUM_FREE value means that no quorum algorithm is loaded and that no callbacks will take place.

       QUORUM_SET value means that one quorum algorithm is configured and that callbacks will take place.

       The context argument sets context same way as quorum_context_set(3).

       When a configuration change occurs, the callback is called from the quorum_dispatch(3) function.

RETURN VALUE

       This call returns the CS_OK value if successful, otherwise an error is returned.

ERRORS

       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

SEE ALSO

       quorum_overview(3), quorum_initialize(3), quorum_finalize(3), quorum_getquorate(3), quorum_trackstart(3),
       quorum_trackstop(3), quorum_fd_get(3), quorum_dispatch(3), quorum_context_set(3), quorum_context_get(3)