<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 08:02:49 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-11443] Docs for SERVER-32630: Minimize reads of the featureCompatibilityVersion parameter that occur prior to the featureCompatibilityVersion document being read/created</title>
                <link>https://jira.mongodb.org/browse/DOCS-11443</link>
                <project id="10380" key="DOCS">Documentation</project>
                    <description>&lt;h1&gt;&lt;a name=&quot;DocumentationRequestSummary%3A&quot;&gt;&lt;/a&gt;Documentation Request Summary: &lt;/h1&gt;

&lt;p&gt;As of this patch, arbiters now set their featureCompatibilityVersion to the latest version by default. This means that if users have to downgrade their arbiters, they will have to delete the arbiter data files in case there were any backwards-incompatible schema changes that were gated on the featureCompatibilityVersion.&lt;/p&gt;

&lt;h1&gt;&lt;a name=&quot;EngineeringTicketDescription%3A&quot;&gt;&lt;/a&gt;Engineering Ticket Description:&lt;/h1&gt;

&lt;p&gt;Presently, there are places in the server code that read the featureCompatibilityVersion parameter before it is explicitly initialized with a meaningful value either from &lt;a href=&quot;https://github.com/mongodb/mongo/blob/8cb7435be3529fb4f982ec53373db5ecd9ad4efb/src/mongo/db/db.cpp#L526-L554&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;reading the featureCompatibilityVersion document&lt;/a&gt; or &lt;a href=&quot;https://github.com/mongodb/mongo/blob/8cb7435be3529fb4f982ec53373db5ecd9ad4efb/src/mongo/db/commands/feature_compatibility_version.cpp#L232-L234&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;creating a new featureCompatibilityVersion document&lt;/a&gt; on clean startup. These reads should be minimized if not eliminated. A proposal to minimize these reads follows:&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;Continue to &lt;a href=&quot;https://github.com/mongodb/mongo/blob/27ccd4a3bf1150a1bf4356de8a91e4dff64e0762/src/mongo/db/server_options.h#L220&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;default&lt;/a&gt; the featureCompatibilityVersion parameter to the &quot;unset&quot; value.&lt;/li&gt;
	&lt;li&gt;Assert that the featureCompatibilityVersion parameter is not &quot;unset&quot; in the default getter function (&lt;tt&gt;&lt;a href=&quot;https://github.com/mongodb/mongo/blob/27ccd4a3bf1150a1bf4356de8a91e4dff64e0762/src/mongo/db/server_options.h#L196-L203&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;getVersion&lt;/a&gt;&lt;/tt&gt;).&lt;/li&gt;
	&lt;li&gt;For existing reads of the featureCompatibilityVersion parameter, find all reads that occur prior to the document being read. Most if not all of these should be 3.4 to 3.6 specific and thus get removed. If any such reads remain after removal of 3.4 to 3.6-specific behavior, and they must be kept, handle them with a special unsafe getter function that treats the &quot;unset&quot; value as last-stable.&lt;/li&gt;
&lt;/ul&gt;
</description>
                <environment></environment>
        <key id="510508">DOCS-11443</key>
            <summary>Docs for SERVER-32630: Minimize reads of the featureCompatibilityVersion parameter that occur prior to the featureCompatibilityVersion document being read/created</summary>
                <type id="3" iconUrl="https://jira.mongodb.org/secure/viewavatar?size=xsmall&amp;avatarId=14718&amp;avatarType=issuetype">Task</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="13203">Gone away</resolution>
                                        <assignee username="kay.kim@mongodb.com">Kay Kim</assignee>
                                    <reporter username="kay.kim@mongodb.com">Kay Kim</reporter>
                        <labels>
                    </labels>
                <created>Tue, 13 Mar 2018 15:39:19 +0000</created>
                <updated>Fri, 27 Oct 2023 20:16:23 +0000</updated>
                            <resolved>Tue, 17 Jul 2018 19:57:45 +0000</resolved>
                                                    <fixVersion>3.7.3</fixVersion>
                                    <component>manual</component>
                    <component>Server</component>
                        <due></due>
                            <votes>0</votes>
                                    <watches>2</watches>
                                                                                                                <comments>
                            <comment id="1949541" author="maria.vankeulen" created="Tue, 17 Jul 2018 19:53:55 +0000"  >&lt;p&gt;&lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=kay.kim&quot; class=&quot;user-hover&quot; rel=&quot;kay.kim&quot;&gt;kay.kim&lt;/a&gt; as of &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-32590&quot; title=&quot;RTT 3.6&amp;lt;-&amp;gt;4.0 upgrade/downgrade.&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-32590&quot;&gt;&lt;del&gt;SERVER-32590&lt;/del&gt;&lt;/a&gt;, we no longer expect to need to delete arbiter data files upon downgrade, since the data files will &lt;a href=&quot;https://github.com/mongodb/mongo/blob/9c0c1bd5b8cc3ba6b9990fb58cbdf5cde575c634/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp#L103-L107&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;automatically get downgraded&lt;/a&gt; on clean shutdown. I believe there are no FCV-4.0 dependent schema changes on the local database, so downgrading the WiredTiger file version should be sufficient for ensuring that a 3.6 arbiter can still start up.&lt;/p&gt;</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10320">
                    <name>Documented</name>
                                            <outwardlinks description="documents">
                                        <issuelink>
            <issuekey id="481135">SERVER-32630</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>1.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_10055" key="com.atlassian.jira.ext.charting:firstresponsedate">
                        <customfieldname>Date of 1st Reply</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>Tue, 17 Jul 2018 19:53:55 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        5 years, 30 weeks, 1 day 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_10857" key="com.pyxis.greenhopper.jira:gh-epic-link">
                        <customfieldname>Epic Link</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>DOCS-11003</customfieldvalue>
                        </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>luke.bonanomi@mongodb.com</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            5 years, 30 weeks, 1 day ago
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                            <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>kay.kim@mongodb.com</customfieldvalue>
            <customfieldvalue>maria.vankeulen@mongodb.com</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|htsivz:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|htjve7:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10558" key="com.pyxis.greenhopper.jira:gh-global-rank">
                        <customfieldname>Rank (Obsolete)</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>9223372036854775807</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_10555" key="com.atlassian.jira.plugin.system.customfieldtypes:float">
                        <customfieldname>Story Points</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1.0</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|hts52v:</customfieldvalue>

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