<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 04:59:52 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-42205] Raise the snapshot window&apos;s cache pressure threshold from 50 to 95</title>
                <link>https://jira.mongodb.org/browse/SERVER-42205</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;p&gt;WT doesn&apos;t trigger eviction until the LAS score reaches a high value. I think 95 is safer for the snapshot window cache pressure threshold, so that we do not stop servicing &apos;snapshot&apos; read concern operations while the cache pressure remains unchanged because WT doesn&apos;t think it high enough for concern yet.&lt;/p&gt;</description>
                <environment></environment>
        <key id="855349">SERVER-42205</key>
            <summary>Raise the snapshot window&apos;s cache pressure threshold from 50 to 95</summary>
                <type id="4" iconUrl="https://jira.mongodb.org/secure/viewavatar?size=xsmall&amp;avatarId=14710&amp;avatarType=issuetype">Improvement</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="dianna.hohensee@mongodb.com">Dianna Hohensee</assignee>
                                    <reporter username="dianna.hohensee@mongodb.com">Dianna Hohensee</reporter>
                        <labels>
                    </labels>
                <created>Fri, 12 Jul 2019 16:34:34 +0000</created>
                <updated>Sun, 29 Oct 2023 22:19:06 +0000</updated>
                            <resolved>Thu, 1 Aug 2019 19:39:53 +0000</resolved>
                                                    <fixVersion>4.2.1</fixVersion>
                    <fixVersion>4.3.1</fixVersion>
                                    <component>Storage</component>
                                        <votes>0</votes>
                                    <watches>3</watches>
                                                                                                                <comments>
                            <comment id="2373911" author="xgen-internal-githook" created="Thu, 15 Aug 2019 17:55:30 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;username&apos;: &apos;DiannaHohensee&apos;, &apos;email&apos;: &apos;dianna.hohensee@10gen.com&apos;, &apos;name&apos;: &apos;Dianna Hohensee&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-42205&quot; title=&quot;Raise the snapshot window&amp;#39;s cache pressure threshold from 50 to 95&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-42205&quot;&gt;&lt;del&gt;SERVER-42205&lt;/del&gt;&lt;/a&gt; Raise the snapshot window&apos;s cache pressure threshold from 50 to 95&lt;/p&gt;

&lt;p&gt;(cherry picked from commit ab48766f3ab9953bf0beb60a64bf8da3a2d0dd0b)&lt;br/&gt;
Branch: v4.2&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/0659c76410c975d826db02e69119a6a1a1fccf98&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/0659c76410c975d826db02e69119a6a1a1fccf98&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="2354939" author="xgen-internal-githook" created="Thu, 1 Aug 2019 19:39:19 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;name&apos;: &apos;Dianna Hohensee&apos;, &apos;email&apos;: &apos;dianna.hohensee@10gen.com&apos;, &apos;username&apos;: &apos;DiannaHohensee&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-42205&quot; title=&quot;Raise the snapshot window&amp;#39;s cache pressure threshold from 50 to 95&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-42205&quot;&gt;&lt;del&gt;SERVER-42205&lt;/del&gt;&lt;/a&gt; Raise the snapshot window&apos;s cache pressure threshold from 50 to 95&lt;br/&gt;
Branch: master&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/ab48766f3ab9953bf0beb60a64bf8da3a2d0dd0b&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/ab48766f3ab9953bf0beb60a64bf8da3a2d0dd0b&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="2327374" author="dianna.hohensee" created="Mon, 15 Jul 2019 17:40:45 +0000"  >&lt;p&gt;Alex suggested 95 in an old email, I believe as part of choosing non-invasive defaults to start. It sounds reasonable to me. It seems pretty hard to finely guess at which LAS score threshold would or would not push us into disk usage if we kept another X (additive increase setting) seconds worth of history.&lt;/p&gt;</comment>
                            <comment id="2327323" author="milkie" created="Mon, 15 Jul 2019 17:04:11 +0000"  >&lt;p&gt;So by choosing 95 this should be a good balance between avoiding cache pressure and continuing to service snapshot reads?  Sounds okay by me then.&lt;/p&gt;</comment>
                            <comment id="2327310" author="dianna.hohensee" created="Mon, 15 Jul 2019 16:57:18 +0000"  >&lt;p&gt;Alex said &quot;Eviction doesn&apos;t rely on the las score. Eviction that writes to cache overflow (aka lookaside) requires either a score of 100 or the cache to be operating in aggressive mode&quot;.&lt;/p&gt;

&lt;p&gt;It seems that even at 95, cache pressure can persist. So whatever LAS score threshold we set, it&apos;s really the point at which we decide to stop allowing data history to push pressure even higher, to start causing disk overflow and slow cache.&lt;/p&gt;</comment>
                            <comment id="2327229" author="milkie" created="Mon, 15 Jul 2019 16:16:09 +0000"  >&lt;p&gt;At what lookaside score does eviction begin in earnest?&lt;/p&gt;</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10420">
                    <name>Backports</name>
                                            <outwardlinks description="backported by">
                                                        </outwardlinks>
                                                        </issuelinktype>
                            <issuelinktype id="10012">
                    <name>Related</name>
                                                                <inwardlinks description="is related to">
                                                        </inwardlinks>
                                    </issuelinktype>
                    </issuelinks>
                <attachments>
                    </attachments>
                <subtasks>
                    </subtasks>
                <customfields>
                                                <customfield id="customfield_10050" key="com.atlassian.jira.toolkit:comments">
                        <customfieldname># Replies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>6.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18555" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname># of Sprints</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2.0</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                <customfield id="customfield_12450" key="com.atlassian.jira.plugin.system.customfieldtypes:multicheckboxes">
                        <customfieldname>Backport Requested</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="16775"><![CDATA[v4.2]]></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>Mon, 15 Jul 2019 16:16:09 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        4 years, 25 weeks, 6 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_17050" key="com.atlassian.jira.plugin.system.customfieldtypes:radiobuttons">
                        <customfieldname>Downstream Team Attention</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="16941"><![CDATA[Not Needed]]></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>
                            4 years, 25 weeks, 6 days ago
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                    <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>dianna.hohensee@mongodb.com</customfieldvalue>
            <customfieldvalue>milkie@mongodb.com</customfieldvalue>
            <customfieldvalue>xgen-internal-githook</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|hve2iv:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|huiau7:</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="3090">Execution Team 2019-07-29</customfieldvalue>
    <customfieldvalue id="3091">Execution Team 2019-08-12</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|hvdos7:</customfieldvalue>

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