votequorum_overview(8) [debian man page]
VOTEQUORUM_OVERVIEW(8) Corosync Cluster Engine Programmer's Manual VOTEQUORUM_OVERVIEW(8) NAME
votequorum_overview - Votequorum Library Overview OVERVIEW
The votequuorum library is delivered with the corosync project. It is the external interface to the vote-based quorum service. This service is optionally loaded into all ndes in a corosync cluster to avoid split-brain situations. It does this by having a number of votes assigned to each system in the cluster and ensuring that only when a majority of the votes are present, cluster operations are allowed to proceed. The library provides a mechanism to: * Query the quorum status * Get a list of nodes known to the quorum service * Receive notifications of quorum state changes * Change the number of votes assigned to a node * Change the number of expected votes for a cluster to be quorate * Connect an additional quorum device to allow small clusters to remain quorate during node outages. votequorum reads its configuration from the objdb. The following keys are read when it starts up: * quorum.expected_votes * quorum.votes * quorum.quorumdev_poll * quorum.disallowed * quorum.two_node Most of those values can be changed while corosync is running with the following exceptions: quorum.disallowed cannot be changed, and two_node cannot be set on-the-fly, though it can be cleared. ie you can start with two nodes in the cluster and add a third without reboot- ing all the nodes. BUGS
This software is not yet production, so there may still be some bugs. SEE ALSO
corosync-quorumtool(8), votequorum_initialize(3), votequorum_finalize(3), votequorum_fd_get(3), votequorum_dispatch(3), votequorum_con- text_get(3), votequorum_context_set(3), corosync Man Page 2009-01-26 VOTEQUORUM_OVERVIEW(8)
Check Out this Related Man Page
VOTEQUORUM_QDEVICE_POLL(3) Corosync Cluster Engine Programmer's Manual VOTEQUORUM_QDEVICE_POLL(3) NAME
votequorum_qdevice_poll - Tells votequorum the result of the quorum device poll SYNOPSIS
#include <corosync/votequorum.h> int votequorum_qdevice_poll(votequorum_handle_t handle, const char * name, unsigned int cast_vote); DESCRIPTION
The votequorum_qdevice_poll is called by the quorum device subsystem (not provided as part of votequorum) to tell the voting system if the quorum device is present/active or not. If cast_vote is 1 then the votes for the device are included in the quorum calculation, otherwise not. This routine should be called at regular intervals to ensure that the device status is always known to votequorum. If votequorum_qde- vice_poll is not called for (default) 10 seconds then the device will be deemed to be dead and its votes removed from the cluster. This does not unregister the device. The default poll time can be changed by setting the cmap variable quorum.quorumdev_poll. 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 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 SEE ALSO
votequorum_overview(8), votequorum_initialize(3), votequorum_finalize(3), votequorum_getinfo(3), votequorum_trackstart(3), votequo- rum_trackstop(3), votequorum_fd_get(3), votequorum_dispatch(3), votequorum_context_set(3), votequorum_context_get(3), votequorum_setex- pected(3), votequorum_setvotes(3), votequorum_qdevice_register(3), votequorum_qdevice_unregister(3), votequorum_qdevice_update(3), votequo- rum_qdevice_master_wins(3), corosync Man Page 2014-06-10 VOTEQUORUM_QDEVICE_POLL(3)