From 1dc3264da63bcbe84b1deef0718f011e016f50ca Mon Sep 17 00:00:00 2001 From: SylvainA77 Date: Tue, 12 Jul 2016 12:06:10 +0200 Subject: [PATCH] Update weightedquorum.rst after some testing it has been determined that the quorum is conserved if the sum weight of the node of a new compenent is equal to half taht of the precedeing primary component. either it's bug or the doc needs some update :) setup : percona cluster 5.6 galera 3.16. node1 : weigth 2, node2 : weight 1, node3 : weight 1. kill -9 mysql on node1. node2 and 3 stays in primary component. old primary component weight = 4, gracefull exit weight = 0, new primary component weight = 2. --- galeracluster/source/weightedquorum.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/galeracluster/source/weightedquorum.rst b/galeracluster/source/weightedquorum.rst index 83efd1e8..8cc8a49e 100644 --- a/galeracluster/source/weightedquorum.rst +++ b/galeracluster/source/weightedquorum.rst @@ -89,9 +89,9 @@ The quorum calculation formula is .. math:: \frac{ \sum_{p_i \times w_i} - \sum_{l_i \times w_i}} - { 2} < \sum_{m_i \times w_i} + { 2} <= \sum_{m_i \times w_i} -.. The original equation read (sum(p_i * w_i) - sum(l_i * w_i)) / 2 < sum(m_i * w_i). Remove this comment after confirming that the LaTeX renders correctly. +.. The original equation read (sum(p_i * w_i) - sum(l_i * w_i)) / 2 <= sum(m_i * w_i). Remove this comment after confirming that the LaTeX renders correctly. Where: @@ -103,7 +103,7 @@ Where: - :math:`w_i` Member weights. -What this means is that the quorum is preserved if (and only if) the sum weight of the nodes in a new component strictly exceeds half that of the preceding :term:`Primary Component`, minus the nodes which left gracefully. +What this means is that the quorum is preserved if (and only if) the sum weight of the nodes in a new component exceeds or is equal to half that of the preceding :term:`Primary Component`, minus the nodes which left gracefully. You can customize node weight using the :ref:`pc.weight ` parameter. By default, node weight is ``1``, which translates to the traditional node count behavior.