1VOTEQUORUM_INITIALICZoEr(o3s)ync Cluster Engine Programmer'sVMOaTnEuQaUlORUM_INITIALIZE(3)
2
6 votequorum_initialize - Create a new connection to the VoteQuorum ser‐
7 vice
8
10 #include <corosync/votequorum.h>
11 int votequorum_initialize(votequorum_handle_t *handle, votequorum_call‐
13 backs_t *callbacks);
14
16 The votequorum_initialize function is used to initialize a connection
17 to the vote-based quorum database API.
18 Each application may have several connections to the votequorum API.
20 Each application uses the handle argument to uniquely identify the con‐
21 nection. The handle argument is then used in other function calls to
22 identify the connection to be used for communication with the votequo‐
23 rum service.
24 Every time the voting configuration is about to change (eg a node joins
26 or leave the cluster), the callback is called. The callback function
27 is described by the following type definitions:
28 typedef void (*votequorum_nodelist_notification_fn_t) (
30 votequorum_handle_t handle,
31 uint64_t context,
32 uint32_t node_list_entries,
33 uint32_t node_list[]
34 );
35 Current ring_id (one get in votequorum_quorum_notification_fn) must be
38 passed to votequorum_qdevice_poll to make qdevice voting valid.
39 Every time the quorum state changes (eg a node joins or leave the clus‐
42 ter), the callback is called. The callback function is described by
43 the following type definitions:
44 typedef void (*votequorum_quorum_notification_fn_t) (
46 votequorum_handle_t handle,
47 uint64_t context,
48 uint32_t quorate,
49 uint32_t node_list_entries,
50 votequorum_node_t node_list[]
51 );
52 The difference between votequorum_nodelist_notification_t and votequo‐
55 rum_quorum_notification_t is subtle but important. The 'nodelist'
56 callback is sent at the start of a cluster state transition and con‐
57 tains the new ring_id and only the list of nodes that are included in
58 the sync state - ie only active nodes. No quorum information is in‐
59 cluded this callback because it is not available at that time. The
60 'quorum' callback is sent after the cluster state transition has com‐
61 pleted and does contain quorum information. In addition, the nodelist
62 contains a list of all nodes known to votequorum (whether up or down)
63 and their state as well as information about the quorum device attached
64 (if any). Quorum callbacks will not be sent for qdevice up and down
65 events unless they affect quorum.
66 Every time the expected votes are changed, the callback is called. The
69 expected votes callback function is described by the following type
70 definitions:
71 typedef void (*votequorum_expectedvotes_notification_fn_t) (
73 votequorum_handle_t handle,
74 uint64_t context,
75 uint32_t expected_votes);
76 The callbacks argument is of the type:
78 typedef struct {
80 votequorum_quorum_notification_fn_t votequorum_quorum_notify_fn;
81 votequorum_expectedvotes_notification_fn_t votequorum_expectedvotes_notify_fn;
82 votequorum_nodelist_notification_fn_t votequorum_nodelist_notify_fn;
83 } votequorum_callbacks_t;
84 When a configuration change occurs, the callback is called from the
86 votequorum_dispatch() function.
87
89 This call returns the CS_OK value if successful, otherwise an error is
90 returned.
91
93 CS_ERR_TRY_AGAIN Resource temporarily unavailable
94 CS_ERR_INVALID_PARAM Invalid argument
96 CS_ERR_ACCESS Permission denied
98 CS_ERR_LIBRARY The connection failed
100 CS_ERR_INTERRUPT System call interrupted by a signal
102 CS_ERR_NOT_SUPPORTED The requested protocol/functionality not supported
104 CS_ERR_MESSAGE_ERROR Incorrect auth message received
106 CS_ERR_NO_MEMORY Not enough memory to complete the requested task
108
111 votequorum_overview(3), votequorum_finalize(3), votequorum_getinfo(3),
112 votequorum_trackstart(3), votequorum_trackstop(3), votequo‐
113 rum_fd_get(3), votequorum_dispatch(3), votequorum_context_set(3), vote‐
114 quorum_context_get(3), votequorum_setexpected(3), votequo‐
115 rum_setvotes(3)
116corosync Man Page 2023-11-15 VOTEQUORUM_INITIALIZE(3)