votequorum_overview(8) [suse 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)

VOTEQUORUM_QDEVICE_REGISTER(3)			    Corosync Cluster Engine Programmer's Manual 		    VOTEQUORUM_QDEVICE_REGISTER(3)

NAME

       votequorum_qdevice_register - Registers a new quorum device

SYNOPSIS

       #include <corosync/votequorum.h>

       int votequorum_qdevice_register(votequorum_handle_t handle, const char * name);

DESCRIPTION

       The  votequorum_qdevice_register  is  used  to  register a new quorum device. A quorum device is an external way of adding votes to a small
       cluster. The quorum device is, in effect, a pseudo node in the cluster that provide votes based on some external device, usually  a  shared
       disk partition or perhaps a network router.
       This  call creates the device but does not mark it active.  votequorum_qdevice_poll must be called for the votes to be included in the quo-
       rum calculation.
       name is string containing an informative name for the quorum device. It is simply stored by votequorum and used in the display of corosync-
       quorumtool, it can be a maximum of 254 characters.
       The  number  of votes contributed by the quorum device is already known to votequorum, it is set in cmap quorum.device.votes and not by the
       device.
       Note that it is the responsibility of the quorum device subsystem (not provided as part of votequorum) to keep all nodes  informed  of  the
       quorum device status.

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_unregister(3),  votequorum_qdevice_poll(3),  votequorum_qdevice_update(3), votequo-
       rum_qdevice_master_wins(3)

corosync Man Page						    2014-06-10					    VOTEQUORUM_QDEVICE_REGISTER(3)