<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 04:54:12 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>[SERVER-40166] Force BG clock now == Date_t::lastNow</title>
                <link>https://jira.mongodb.org/browse/SERVER-40166</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;p&gt;Currently our fast clock is implemented by a background thread which wakes up every 10ms if callers continue to check it&apos;s time.  If that background thread get&apos;s descheduled for a long time for some reason, this can cause the background threads time to drift substantially.&lt;/p&gt;

&lt;p&gt;If we:&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;force every read of date_t::now to update a new date_t::lastNow&lt;/li&gt;
	&lt;li&gt;change the background thread so that it&apos;s responsibility is to wake up and call Date_t::now() (if readers are still present)&lt;/li&gt;
	&lt;li&gt;change the background thread clock source now() to return date_t::lastNow&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;We&apos;ll get a world in which we have the same target granularity + thread quiescence as before, but additionally ensure that even if the background thread can&apos;t be scheduled, that lastNow() will still be pushed loosely forward if there are callers of Date_t::now() elsewhere in the system.  This should ensure a tighter bound on the spread between the precise and fast clock sources&lt;/p&gt;</description>
                <environment></environment>
        <key id="717507">SERVER-40166</key>
            <summary>Force BG clock now == Date_t::lastNow</summary>
                <type id="2" iconUrl="https://jira.mongodb.org/secure/viewavatar?size=xsmall&amp;avatarId=14711&amp;avatarType=issuetype">New Feature</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="13201">Fixed</resolution>
                                        <assignee username="mira.carey@mongodb.com">Mira Carey</assignee>
                                    <reporter username="mira.carey@mongodb.com">Mira Carey</reporter>
                        <labels>
                    </labels>
                <created>Fri, 15 Mar 2019 17:52:11 +0000</created>
                <updated>Sun, 29 Oct 2023 22:22:54 +0000</updated>
                            <resolved>Thu, 21 Mar 2019 18:01:25 +0000</resolved>
                                                    <fixVersion>4.1.10</fixVersion>
                    <fixVersion>4.0.10</fixVersion>
                                    <component>Internal Code</component>
                                        <votes>0</votes>
                                    <watches>0</watches>
                                                                                                                <comments>
                            <comment id="2219638" author="xgen-internal-githook" created="Fri, 19 Apr 2019 20:17:37 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;email&apos;: &apos;jcarey@argv.me&apos;, &apos;name&apos;: &apos;Jason Carey&apos;, &apos;username&apos;: &apos;hanumantmk&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-40166&quot; title=&quot;Force BG clock now == Date_t::lastNow&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-40166&quot;&gt;&lt;del&gt;SERVER-40166&lt;/del&gt;&lt;/a&gt; Force BG clock now &amp;gt;= Date_t::lastNow&lt;/p&gt;

&lt;p&gt;Currently our fast clock is implemented by a background thread which&lt;br/&gt;
wakes up every 10ms if callers continue to check it&apos;s time.  If that&lt;br/&gt;
background thread get&apos;s descheduled for a long time for some reason,&lt;br/&gt;
this can cause the background threads time to drift substantially.&lt;/p&gt;

&lt;p&gt;If we:&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;force every read of date_t::now to update a new date_t::lastNow&lt;/li&gt;
	&lt;li&gt;change the background thread so that it&apos;s responsibility is to wake up&lt;br/&gt;
  and call Date_t::now() (if readers are still present)&lt;/li&gt;
	&lt;li&gt;change the background thread clock source now() to return&lt;br/&gt;
  date_t::lastNow&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;We&apos;ll get a world in which we have the same target granularity + thread&lt;br/&gt;
quiescence as before, but additionally ensure that even if the&lt;br/&gt;
background thread can&apos;t be scheduled, that lastNow() will still be&lt;br/&gt;
pushed loosely forward if there are callers of Date_t::now() elsewhere&lt;br/&gt;
in the system.  This should ensure a tighter bound on the spread between&lt;br/&gt;
the precise and fast clock sources&lt;/p&gt;

&lt;p&gt;(cherry picked from commit d32ddac33c48b5e2d2885c2862d6abd88e7f26d2)&lt;br/&gt;
Branch: v4.0&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/43fb7ff820793bcc94e160133cc1dacd12bec1c8&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/43fb7ff820793bcc94e160133cc1dacd12bec1c8&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="2187732" author="xgen-internal-githook" created="Thu, 21 Mar 2019 18:00:44 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;name&apos;: &apos;Jason Carey&apos;, &apos;username&apos;: &apos;hanumantmk&apos;, &apos;email&apos;: &apos;jcarey@argv.me&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-40166&quot; title=&quot;Force BG clock now == Date_t::lastNow&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-40166&quot;&gt;&lt;del&gt;SERVER-40166&lt;/del&gt;&lt;/a&gt; Force BG clock now &amp;gt;= Date_t::lastNow&lt;/p&gt;

&lt;p&gt;Currently our fast clock is implemented by a background thread which&lt;br/&gt;
wakes up every 10ms if callers continue to check it&apos;s time.  If that&lt;br/&gt;
background thread get&apos;s descheduled for a long time for some reason,&lt;br/&gt;
this can cause the background threads time to drift substantially.&lt;/p&gt;

&lt;p&gt;If we:&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;force every read of date_t::now to update a new date_t::lastNow&lt;/li&gt;
	&lt;li&gt;change the background thread so that it&apos;s responsibility is to wake up&lt;br/&gt;
  and call Date_t::now() (if readers are still present)&lt;/li&gt;
	&lt;li&gt;change the background thread clock source now() to return&lt;br/&gt;
  date_t::lastNow&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;We&apos;ll get a world in which we have the same target granularity + thread&lt;br/&gt;
quiescence as before, but additionally ensure that even if the&lt;br/&gt;
background thread can&apos;t be scheduled, that lastNow() will still be&lt;br/&gt;
pushed loosely forward if there are callers of Date_t::now() elsewhere&lt;br/&gt;
in the system.  This should ensure a tighter bound on the spread between&lt;br/&gt;
the precise and fast clock sources&lt;br/&gt;
Branch: master&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/d32ddac33c48b5e2d2885c2862d6abd88e7f26d2&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/d32ddac33c48b5e2d2885c2862d6abd88e7f26d2&lt;/a&gt;&lt;/p&gt;</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10420">
                    <name>Backports</name>
                                            <outwardlinks description="backported by">
                                                        </outwardlinks>
                                                        </issuelinktype>
                            <issuelinktype id="10011">
                    <name>Depends</name>
                                                                <inwardlinks description="is depended on by">
                                                        </inwardlinks>
                                    </issuelinktype>
                            <issuelinktype id="10012">
                    <name>Related</name>
                                            <outwardlinks description="related to">
                                        <issuelink>
            <issuekey id="717505">SERVER-40165</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>2.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18555" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname># of Sprints</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1.0</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                <customfield id="customfield_12450" key="com.atlassian.jira.plugin.system.customfieldtypes:multicheckboxes">
                        <customfieldname>Backport Requested</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="15640"><![CDATA[v4.0]]></customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10011" key="com.atlassian.jira.plugin.system.customfieldtypes:radiobuttons">
                        <customfieldname>Backwards Compatibility</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="10038"><![CDATA[Fully Compatible]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                            <customfield id="customfield_10055" key="com.atlassian.jira.ext.charting:firstresponsedate">
                        <customfieldname>Date of 1st Reply</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>Thu, 21 Mar 2019 18:00:44 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        4 years, 42 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>luke.bonanomi@mongodb.com</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            4 years, 42 weeks, 5 days ago
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_16465" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Linked BF Score</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>8.0</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>xgen-internal-githook</customfieldvalue>
            <customfieldvalue>mira.carey@mongodb.com</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|huqxbz:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hugjjr:</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_23361" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Requested By</customfieldname>
                        <customfieldvalues>
                                

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_10557" key="com.pyxis.greenhopper.jira:gh-sprint">
                        <customfieldname>Sprint</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue id="2857">Service Arch 2019-03-25</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_22870" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Triagers</customfieldname>
                        <customfieldvalues>
                                

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                    <customfield id="customfield_14350" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>serverRank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|huqjlb:</customfieldvalue>

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