<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 04:11:18 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-26157] deadlock during LVM snapshot</title>
                <link>https://jira.mongodb.org/browse/SERVER-26157</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;p&gt;I am testing backup of a standalone mongodb using LVM snapshot. I have journaling enabled so mongod is running and processing requests.&lt;/p&gt;

&lt;p&gt;It happened just once that I run into a deadlock situation. There is one jbd2 and three mongod threads reported blocked in the syslog (attached with back traces) and another jdb2 and two more mongod threads after exactly two minutes.&lt;/p&gt;
&lt;p/&gt;
&lt;div id=&quot;syntaxplugin&quot; class=&quot;syntaxplugin&quot; style=&quot;border: 1px dashed #bbb; border-radius: 5px !important; overflow: auto; max-height: 30em;&quot;&gt;
&lt;table cellspacing=&quot;0&quot; cellpadding=&quot;0&quot; border=&quot;0&quot; width=&quot;100%&quot; style=&quot;font-size: 1em; line-height: 1.4em !important; font-weight: normal; font-style: normal; color: black;&quot;&gt;
		&lt;tbody &gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;  margin-top: 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:03:01 dss2 kernel: [719046.057796] EXT4-fs (dm-5): mounted filesystem with ordered data mode. Opts: (null)&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.567904] INFO: task jbd2/dm-2-8:9048 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.568130] INFO: task mongod:23239 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.568267] INFO: task mongod:23242 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.568350] INFO: task mongod:23243 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.568397] INFO: task dmeventd:12427 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.568523] INFO: task kworker/u16:2:31890 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:06:53 dss2 kernel: [719277.568713] INFO: task tar:12446 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:08:53 dss2 kernel: [719397.567614] INFO: task jbd2/dm-2-8:9048 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:08:53 dss2 kernel: [719397.567731] INFO: task mongod:23239 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
				&lt;tr id=&quot;syntaxplugin_code_and_gutter&quot;&gt;
						&lt;td  style=&quot; line-height: 1.4em !important; padding: 0em; vertical-align: top;&quot;&gt;
					&lt;pre style=&quot;font-size: 1em; margin: 0 10px;   margin-bottom: 10px;  width: auto; padding: 0;&quot;&gt;&lt;span style=&quot;color: black; font-family: &apos;Consolas&apos;, &apos;Bitstream Vera Sans Mono&apos;, &apos;Courier New&apos;, Courier, monospace !important;&quot;&gt;Sep 15 17:08:53 dss2 kernel: [719397.567870] INFO: task mongod:23240 blocked for more than 120 seconds.&lt;/span&gt;&lt;/pre&gt;
			&lt;/td&gt;
		&lt;/tr&gt;
			&lt;/tbody&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;p/&gt;
&lt;p&gt;The last processing as reported in mongod.log was at 2016-09-15T17:08:27.808+0200, after that just the number of open connections accumulates.&lt;/p&gt;

&lt;p&gt;I was not abble to terminate the tar process and unmount the snapshot. Also mongod was not stoppable and whole system had to be rebooted.&lt;/p&gt;

&lt;p&gt;I am running Ubuntu 16.04.1 with mongod 3.2.9 on a 64bit system.&lt;/p&gt;</description>
                <environment></environment>
        <key id="317066">SERVER-26157</key>
            <summary>deadlock during LVM snapshot</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="5">Cannot Reproduce</resolution>
                                        <assignee username="kelsey.schubert@mongodb.com">Kelsey Schubert</assignee>
                                    <reporter username="tomazb">Tomaz Beltram</reporter>
                        <labels>
                    </labels>
                <created>Mon, 19 Sep 2016 09:25:35 +0000</created>
                <updated>Thu, 1 Dec 2016 23:51:39 +0000</updated>
                            <resolved>Tue, 27 Sep 2016 17:55:13 +0000</resolved>
                                    <version>3.2.9</version>
                                                                        <votes>0</votes>
                                    <watches>6</watches>
                                                                                                                <comments>
                            <comment id="1447395" author="thomas.schubert" created="Thu, 1 Dec 2016 23:51:39 +0000"  >&lt;p&gt;Thanks for following up, &lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=tomazb&quot; class=&quot;user-hover&quot; rel=&quot;tomazb&quot;&gt;tomazb&lt;/a&gt;! I&apos;m glad you were able to identify the root cause.&lt;/p&gt;</comment>
                            <comment id="1444286" author="tomazb" created="Tue, 29 Nov 2016 09:26:01 +0000"  >&lt;p&gt;FYI: Its a kernel race indeed, reported to &lt;a href=&quot;https://www.redhat.com/archives/linux-lvm/2016-November/msg00037.html&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;linux-lvm&lt;/a&gt; and &lt;a href=&quot;https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/1645636&quot; class=&quot;external-link&quot; target=&quot;_blank&quot; rel=&quot;nofollow noopener&quot;&gt;launchpad&lt;/a&gt;.&lt;/p&gt;</comment>
                            <comment id="1394839" author="thomas.schubert" created="Tue, 27 Sep 2016 17:55:13 +0000"  >&lt;p&gt;Hi &lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=tomazb&quot; class=&quot;user-hover&quot; rel=&quot;tomazb&quot;&gt;tomazb&lt;/a&gt;,&lt;/p&gt;

&lt;p&gt;Thank you for the additional information. I have taken a look at the diagnostic.data and do not see anything that indicates a bug in MongoDB. Since we are unable to reproduce this issue and the behavior may be explained a kernel bug, I am going to close this ticket. If you encounter this issue again, please let us know and we will continue to investigate.&lt;/p&gt;

&lt;p&gt;Thank you,&lt;br/&gt;
Thomas&lt;/p&gt;</comment>
                            <comment id="1388396" author="tomazb" created="Tue, 20 Sep 2016 07:26:04 +0000"  >&lt;p&gt;Hi,&lt;/p&gt;

&lt;p&gt;Thanks for your quick reply and for looking into this issue. As I mentioned it only happened once and I was not able to reproduce it even with more frequent backups and higher load on mongodb. The command for creating the snapshot is:&lt;/p&gt;

&lt;p&gt;lvcreate --size 1G --snapshot --name mdb-backupsnap /dev/vgDB/db&lt;/p&gt;

&lt;p&gt;The backup commands have some additional error checking but resolve to:&lt;/p&gt;

&lt;p&gt;mount /dev/vgDB/mdb-backupsnap /mnt/snapshot&lt;br/&gt;
cd /mnt/snapshot&lt;br/&gt;
tar czf $backup-file *&lt;br/&gt;
cd -&lt;br/&gt;
umount /mnt/snapshot&lt;br/&gt;
lvremove -f /dev/vgDB/mdb-backupsnap&lt;/p&gt;

&lt;p&gt;The diagnostic.data archive is attached.&lt;/p&gt;

&lt;p&gt;Thanks again&lt;br/&gt;
Tomaz&lt;/p&gt;</comment>
                            <comment id="1387605" author="thomas.schubert" created="Mon, 19 Sep 2016 16:11:27 +0000"  >&lt;p&gt;Hi &lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=tomazb&quot; class=&quot;user-hover&quot; rel=&quot;tomazb&quot;&gt;tomazb&lt;/a&gt;,&lt;/p&gt;

&lt;p&gt;Thank you for reporting this issue. So we can get a better understanding of what is happening here, would you please provide the following information?&lt;/p&gt;

&lt;ul&gt;
	&lt;li&gt;An explicit walk-through of the steps and commands you executed to create the LVM snapshot when this issue occurred&lt;/li&gt;
	&lt;li&gt;An archive of the &lt;tt&gt;diagnostic.data&lt;/tt&gt; directory&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;Thank you,&lt;br/&gt;
Thomas&lt;/p&gt;</comment>
                    </comments>
                    <attachments>
                            <attachment id="138956" name="17.log" size="46813" author="tomazb" created="Mon, 19 Sep 2016 09:25:35 +0000"/>
                            <attachment id="139111" name="diagnostic.data.tgz" size="110815669" author="tomazb" created="Tue, 20 Sep 2016 07:18:02 +0000"/>
                    </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>Mon, 19 Sep 2016 16:11:27 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        7 years, 10 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_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>kelsey.schubert@mongodb.com</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            7 years, 10 weeks, 6 days ago
                        </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>kelsey.schubert@mongodb.com</customfieldvalue>
            <customfieldvalue>tomazb</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|hrjvtz:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hspvr3:</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_10750" key="com.atlassian.jira.plugin.system.customfieldtypes:textarea">
                        <customfieldname>Steps To Reproduce</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>&lt;p&gt;Difficult, happened just once.&lt;/p&gt;</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>
                                    <customfieldvalue><![CDATA[kelsey.schubert@mongodb.com]]></customfieldvalue>
    

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

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