<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 05:04:17 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-43848] find/update/delete w/o shard key predicate under txn with snapshot read can miss documents</title>
                <link>https://jira.mongodb.org/browse/SERVER-43848</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;p&gt;Scenario:&lt;/p&gt;

&lt;p&gt;shardKey: x: 1&lt;br/&gt;
chunks: [MinKey, 0) @ shard1, [0, MaxKey) @ shard0&lt;/p&gt;

&lt;p&gt;1. Txn sets read concern timestamp to t5.&lt;br/&gt;
2. Migration move document x: 1, y: 1, from shard0 (last chunk) to shard1 at t10.&lt;br/&gt;
3. Mongos refreshes to latest chunk metadata.&lt;br/&gt;
4. Txn targets update/delete with predicate y: 1. This will generate an index bound of [MinKey, MaxKey).&lt;br/&gt;
5. ChunkManager::getShardIdsForRange will go through every chunk that overlaps with [MinKey, MaxKey) and &lt;a href=&quot;https://github.com/mongodb/mongo/blob/r4.3.0/src/mongo/s/chunk_manager.cpp#L194&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;get the shardId at t5&lt;/a&gt;.&lt;br/&gt;
6. However, the loop has an optimization to &lt;a href=&quot;https://github.com/mongodb/mongo/blob/r4.3.0/src/mongo/s/chunk_manager.cpp#L198&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;early exit if the number of shards that should be targeted is equal to the shard version map&lt;/a&gt;. This will cause the loop to exit early and cause the write to target only shard1.&lt;/p&gt;

&lt;p&gt;The issue here is that the shard version map only include shards with chunks and represents the mapping at t10 and not t5. In the case above, there were 2 shards that had chunks at t5, but only 1 shard that had chunks at t10. Even though the document is currently in shard1, the update/remove will not see it because it is running under the snapshot with ts = t5.&lt;/p&gt;</description>
                <environment></environment>
        <key id="960155">SERVER-43848</key>
            <summary>find/update/delete w/o shard key predicate under txn with snapshot read can miss documents</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="13201">Fixed</resolution>
                                        <assignee username="randolph@mongodb.com">Randolph Tan</assignee>
                                    <reporter username="randolph@mongodb.com">Randolph Tan</reporter>
                        <labels>
                            <label>sharding-wfbf-day</label>
                    </labels>
                <created>Fri, 4 Oct 2019 20:08:13 +0000</created>
                <updated>Sun, 29 Oct 2023 22:16:24 +0000</updated>
                            <resolved>Wed, 4 Mar 2020 17:56:40 +0000</resolved>
                                    <version>4.2.0</version>
                                    <fixVersion>4.2.6</fixVersion>
                    <fixVersion>4.4.0-rc0</fixVersion>
                    <fixVersion>4.7.0</fixVersion>
                                    <component>Sharding</component>
                                        <votes>0</votes>
                                    <watches>6</watches>
                                                                                                                <comments>
                            <comment id="3031792" author="xgen-internal-githook" created="Wed, 8 Apr 2020 19:15:05 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;name&apos;: &apos;Randolph Tan&apos;, &apos;email&apos;: &apos;randolph@10gen.com&apos;, &apos;username&apos;: &apos;renctan&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-43848&quot; title=&quot;find/update/delete w/o shard key predicate under txn with snapshot read can miss documents&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-43848&quot;&gt;&lt;del&gt;SERVER-43848&lt;/del&gt;&lt;/a&gt; find/update/delete w/o shard key predicate under txn with snapshot read can miss documents&lt;/p&gt;

&lt;p&gt;(cherry picked from commit 305bbe0ed709ffc88916093cfbd716bfb8fea60b)&lt;br/&gt;
Branch: v4.2&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/72e265eccbb6e49497eb386a0829ed75bae8c032&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/72e265eccbb6e49497eb386a0829ed75bae8c032&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="3002595" author="xgen-internal-githook" created="Thu, 26 Mar 2020 16:11:44 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;name&apos;: &apos;Randolph Tan&apos;, &apos;username&apos;: &apos;renctan&apos;, &apos;email&apos;: &apos;randolph@10gen.com&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-43848&quot; title=&quot;find/update/delete w/o shard key predicate under txn with snapshot read can miss documents&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-43848&quot;&gt;&lt;del&gt;SERVER-43848&lt;/del&gt;&lt;/a&gt; find/update/delete w/o shard key predicate under txn with snapshot read can miss documents&lt;/p&gt;

&lt;p&gt;(cherry picked from commit 305bbe0ed709ffc88916093cfbd716bfb8fea60b)&lt;br/&gt;
Branch: v4.4&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/aeb7bc16841ba15794e0b5615feec0f01c494711&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/aeb7bc16841ba15794e0b5615feec0f01c494711&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="2934616" author="xgen-internal-githook" created="Wed, 4 Mar 2020 17:02:20 +0000"  >&lt;p&gt;Author:&lt;/p&gt;
{&apos;username&apos;: &apos;renctan&apos;, &apos;name&apos;: &apos;Randolph Tan&apos;, &apos;email&apos;: &apos;randolph@10gen.com&apos;}
&lt;p&gt;Message: &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-43848&quot; title=&quot;find/update/delete w/o shard key predicate under txn with snapshot read can miss documents&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-43848&quot;&gt;&lt;del&gt;SERVER-43848&lt;/del&gt;&lt;/a&gt; find/update/delete w/o shard key predicate under txn with snapshot read can miss documents&lt;br/&gt;
Branch: master&lt;br/&gt;
&lt;a href=&quot;https://github.com/mongodb/mongo/commit/305bbe0ed709ffc88916093cfbd716bfb8fea60b&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;https://github.com/mongodb/mongo/commit/305bbe0ed709ffc88916093cfbd716bfb8fea60b&lt;/a&gt;&lt;/p&gt;</comment>
                            <comment id="2474011" author="renctan" created="Wed, 9 Oct 2019 15:43:14 +0000"  >&lt;p&gt;I think you&apos;re right. Updated title.&lt;/p&gt;</comment>
                            <comment id="2473965" author="jack.mulrow" created="Wed, 9 Oct 2019 15:22:28 +0000"  >&lt;p&gt;I think this affects reads too, since they also use &lt;tt&gt;ChunkManager::getShardIdsForRange()&lt;/tt&gt; when targeting shards (&lt;a href=&quot;https://github.com/mongodb/mongo/blob/3cb9e7903a/src/mongo/s/cluster_commands_helpers.cpp#L549&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;through the &lt;tt&gt;getTargetedShardsForQuery()&lt;/tt&gt; helper&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>
                    </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_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="18953"><![CDATA[v4.4]]></customfieldvalue>
    <customfieldvalue key="16775"><![CDATA[v4.2]]></customfieldvalue>
    <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>Wed, 9 Oct 2019 15:22:28 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        3 years, 44 weeks 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>
                            3 years, 44 weeks ago
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_16465" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Linked BF Score</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>7.0</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                        <customfield id="customfield_10032" key="com.atlassian.jira.plugin.system.customfieldtypes:select">
                        <customfieldname>Operating System</customfieldname>
                        <customfieldvalues>
                                <customfieldvalue key="10026"><![CDATA[ALL]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_10051" key="com.atlassian.jira.toolkit:participants">
                        <customfieldname>Participants</customfieldname>
                        <customfieldvalues>
                                        <customfieldvalue>xgen-internal-githook</customfieldvalue>
            <customfieldvalue>jack.mulrow@mongodb.com</customfieldvalue>
            <customfieldvalue>randolph@mongodb.com</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|hvvw2f:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hvkflz:</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="3653">Sharding 2020-03-09</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|hvvibr:</customfieldvalue>

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