<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 07:42:27 UTC 2024

It is possible to restrict the fields that are returned in this document by specifying the 'field' parameter in your request.
For example, to request only the issue key and summary append 'field=key&field=summary' to the URL of your request.
-->
<rss version="0.92" >
<channel>
    <title>MongoDB Jira</title>
    <link>https://jira.mongodb.org</link>
    <description>This file is an XML representation of an issue</description>
    <language>en-us</language>    <build-info>
        <version>9.7.1</version>
        <build-number>970001</build-number>
        <build-date>13-04-2023</build-date>
    </build-info>


<item>
            <title>[DOCS-2008] Geographically distributed replica set - why majority of voting nodes in one place?</title>
                <link>https://jira.mongodb.org/browse/DOCS-2008</link>
                <project id="10380" key="DOCS">Documentation</project>
                    <description>&lt;p&gt;In &lt;a href=&quot;http://docs.mongodb.org/manual/tutorial/deploy-geographically-distributed-replica-set/&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;http://docs.mongodb.org/manual/tutorial/deploy-geographically-distributed-replica-set/&lt;/a&gt;, the documentation claims that you should &quot;Ensure that a majority of the voting members are within a primary facility&quot;, however:&lt;/p&gt;

&lt;p&gt;1) The documentation offers no explanation for why you should ensure the majority of voting members are all in one place.  This seems counter-intuitive, as if this entire data center goes down, it will take a majority of the voting nodes with it, rendering the replica set unable to elect a new master.  It seems that placing two nodes an the arbiter each in three different locations would be a better solution.&lt;/p&gt;

&lt;p&gt;2) The latest version of this documentation in master states: &quot;For more information  on the need to keep the voting majority on one site, see&lt;br/&gt;
  :doc:`/core/replica-set-elections`&quot;.  The referenced page, however, only talks about network partitions, and not about the failure of a data center.&lt;/p&gt;

&lt;p&gt;&lt;a href=&quot;https://github.com/mongodb/docs/blob/master/source/tutorial/deploy-geographically-distributed-replica-set.txt#L39&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/docs/blob/master/source/tutorial/deploy-geographically-distributed-replica-set.txt#L39&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;3) At the bottom of the document is this diagram:&lt;/p&gt;

&lt;p&gt;&lt;a href=&quot;http://docs.mongodb.org/manual/_images/replica-set-three-data-centers.png&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;http://docs.mongodb.org/manual/_images/replica-set-three-data-centers.png&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;Where there are clearly &lt;b&gt;not&lt;/b&gt; a majority of voting nodes in a single data center.&lt;/p&gt;</description>
                <environment></environment>
        <key id="91908">DOCS-2008</key>
            <summary>Geographically distributed replica set - why majority of voting nodes in one place?</summary>
                <type id="1" iconUrl="https://jira.mongodb.org/secure/viewavatar?size=xsmall&amp;avatarId=14703&amp;avatarType=issuetype">Bug</type>
                                            <priority id="3" iconUrl="https://jira.mongodb.org/images/icons/priorities/major.svg">Major - P3</priority>
                        <status id="6" iconUrl="https://jira.mongodb.org/images/icons/statuses/closed.png" description="The issue is considered finished, the resolution is correct. Issues which are closed can be reopened.">Closed</status>
                    <statusCategory id="3" key="done" colorName="success"/>
                                    <resolution id="9">Done</resolution>
                                        <assignee username="kay.kim@mongodb.com">Kay Kim</assignee>
                                    <reporter username="jwalton">Jason Walton</reporter>
                        <labels>
                            <label>replicaset</label>
                            <label>replication</label>
                    </labels>
                <created>Fri, 27 Sep 2013 21:39:54 +0000</created>
                <updated>Wed, 11 Jan 2017 22:42:46 +0000</updated>
                            <resolved>Fri, 27 Sep 2013 22:44:20 +0000</resolved>
                                                    <fixVersion>01112017-cleanup</fixVersion>
                                    <component>manual</component>
                        <due></due>
                            <votes>0</votes>
                                    <watches>2</watches>
                                                                                                                <comments>
                            <comment id="432724" author="jwalton" created="Fri, 27 Sep 2013 23:44:03 +0000"  >&lt;p&gt;Thanks Kay, that does clarify.  We were planning three nodes total; one in east-1, one in west-1, and an arbiter somewhere else.&lt;/p&gt;</comment>
                            <comment id="432722" author="kay.kim@10gen.com" created="Fri, 27 Sep 2013 23:33:45 +0000"  >&lt;p&gt;Hey Jason &amp;#8211; &lt;br/&gt;
the documentation is considering just the network partition scenario. So, for your suggested distribution where it&apos;s 2 member + 1 arbitrary per datacenter , and there are 3 data centers, 9 total members, so you would need majority of 5 to elect a new primary, but if network partition prevents communications among members, then if any one of your data centers go down or if a member goes down, you can&apos;t get a majority.&lt;/p&gt;

&lt;p&gt;As for the case of if a whole data center goes down &amp;#8211; let&apos;s say for a 4 members + 1 arbiter set, then you could have  2 members each in 2 data center and an arbiter not within either datacenter, but separate and yet can see both.  Then if a center goes down, you&apos;re still left with 2 member + 1 arbiter.  &lt;/p&gt;

&lt;p&gt;Hope this helps.&lt;/p&gt;

&lt;p&gt;Regards,&lt;/p&gt;

&lt;p&gt;Kay&lt;/p&gt;</comment>
                            <comment id="432717" author="jwalton" created="Fri, 27 Sep 2013 23:17:11 +0000"  >&lt;p&gt;For example, a week ago EC2 US-East-1 went unreachable on Friday morning for about an hour.  If we&apos;d had Mongo configured with a majority of nodes in US-East-1, then our application would have been entirely unreachable.&lt;/p&gt;</comment>
                            <comment id="432713" author="jwalton" created="Fri, 27 Sep 2013 23:10:17 +0000"  >&lt;p&gt;I still don&apos;t understand this, though; if the majority of voting nodes are in a single data center, then if that data center fails the remaining nodes will be unable to elect a majority, so why would you set up your configuration this way?&lt;/p&gt;</comment>
                            <comment id="432701" author="auto" created="Fri, 27 Sep 2013 22:43:59 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{u&apos;username&apos;: u&apos;kay-kim&apos;, u&apos;name&apos;: u&apos;kay&apos;, u&apos;email&apos;: u&apos;kay.kim@10gen.com&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/DOCS-2008&quot; title=&quot;Geographically distributed replica set - why majority of voting nodes in one place?&quot; class=&quot;issue-link&quot; data-issue-key=&quot;DOCS-2008&quot;&gt;&lt;del&gt;DOCS-2008&lt;/del&gt;&lt;/a&gt;: remove erroneous 3 data centers image and clarify benefit of multiple locations&lt;br/&gt;
Branch: master&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/docs/commit/3ea78d9e005d78b0d636015dea7084371343911a&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/docs/commit/3ea78d9e005d78b0d636015dea7084371343911a&lt;/a&gt;&lt;/p&gt;</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10012">
                    <name>Related</name>
                                            <outwardlinks description="related to">
                                        <issuelink>
            <issuekey id="157208">DOCS-4011</issuekey>
        </issuelink>
                            </outwardlinks>
                                                        </issuelinktype>
                    </issuelinks>
                <attachments>
                    </attachments>
                <subtasks>
                    </subtasks>
                <customfields>
                                                <customfield id="customfield_10050" key="com.atlassian.jira.toolkit:comments">
                        <customfieldname># Replies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>5.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_10055" key="com.atlassian.jira.ext.charting:firstresponsedate">
                        <customfieldname>Date of 1st Reply</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>Fri, 27 Sep 2013 22:43:59 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        10 years, 20 weeks, 5 days ago
    
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18254" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Dependencies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue><![CDATA[]]></customfieldvalue>


                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_15850" key="com.atlassian.jira.plugins.jira-development-integration-plugin:devsummary">
                        <customfieldname>Development</customfieldname>
                        <customfieldvalues>
                            
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    <customfield id="customfield_10057" key="com.atlassian.jira.toolkit:lastusercommented">
                        <customfieldname>Last comment by Customer</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>true</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10056" key="com.atlassian.jira.toolkit:lastupdaterorcommenter">
                        <customfieldname>Last commenter</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>jess.mokrzecki@mongodb.com</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            10 years, 20 weeks, 5 days ago
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                            <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>auto</customfieldvalue>
            <customfieldvalue>jwalton</customfieldvalue>
            <customfieldvalue>kay.kim@mongodb.com</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|hrrnl3:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hrt6dr:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10558" key="com.pyxis.greenhopper.jira:gh-global-rank">
                        <customfieldname>Rank (Obsolete)</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>84117</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    <customfield id="customfield_10053" key="com.atlassian.jira.ext.charting:timeinstatus">
                        <customfieldname>Time In Status</customfieldname>
                        <customfieldvalues>
                            
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            <customfield id="customfield_14350" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>serverRank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|hrypsf:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                </customfields>
    </item>
</channel>
</rss>