<!-- 
RSS generated by JIRA (9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66) at Thu Feb 08 03:47:16 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-18314] Stall during fdatasync phase of checkpoints under WiredTiger and EXT4</title>
                <link>https://jira.mongodb.org/browse/SERVER-18314</link>
                <project id="10000" key="SERVER">Core Server</project>
                    <description>&lt;ul&gt;
	&lt;li&gt;YCSB 30M documents, 10 fields, ~1kB/document, total ~30GB&lt;/li&gt;
	&lt;li&gt;50/50 read/update workload&lt;/li&gt;
	&lt;li&gt;40 GB cache, 128 GB memory, 32 CPUs&lt;/li&gt;
	&lt;li&gt;slow SSD disk (~80-100 MB/s)&lt;/li&gt;
	&lt;li&gt;no journal (to simplify the situation)&lt;/li&gt;
	&lt;li&gt;per mongostat, cache is at 100% utilization, 80% dirty pretty much throughout the test.&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;During each checkpoint two calls to fdatasync are made. Because this scenario is i/o constrained the fdatasyncs take a substantial amount of time, and during both fdatasync calls throughput falls to exactly 0 for the duration of the fdatasync. This is seen in A-B, C-D, E-F, G-H, I-J, K-L below.&lt;/p&gt;

&lt;p&gt;In many, but not all, such cases WT bumps the &quot;eviction server unable to reach goal&quot; counter.&lt;/p&gt;

&lt;p&gt;&lt;span class=&quot;image-wrap&quot; style=&quot;&quot;&gt;&lt;img src=&quot;https://jira.mongodb.org/secure/attachment/72796/72796_try-13.png&quot; width=&quot;900&quot; style=&quot;border: 0px solid black&quot; /&gt;&lt;/span&gt;&lt;/p&gt;

&lt;p&gt;Similar test with a larger cache (the default 64GB) does &lt;em&gt;not&lt;/em&gt; show this issue.&lt;/p&gt;

&lt;p&gt;Note: this is the same test as reported in &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-18315&quot; title=&quot;Throughput drop during transaction pinned phase of checkpoints under WiredTiger&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-18315&quot;&gt;&lt;del&gt;SERVER-18315&lt;/del&gt;&lt;/a&gt;; opening two separate tickets to track what may be separate issues.&lt;/p&gt;</description>
                <environment></environment>
        <key id="201913">SERVER-18314</key>
            <summary>Stall during fdatasync phase of checkpoints under WiredTiger and EXT4</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="3">Duplicate</resolution>
                                        <assignee username="ramon.fernandez@mongodb.com">Ramon Fernandez Marina</assignee>
                                    <reporter username="bruce.lucas@mongodb.com">Bruce Lucas</reporter>
                        <labels>
                            <label>WTplaybook</label>
                            <label>wttt</label>
                    </labels>
                <created>Mon, 4 May 2015 19:51:54 +0000</created>
                <updated>Thu, 9 Nov 2023 01:04:39 +0000</updated>
                            <resolved>Fri, 19 Jun 2015 14:44:45 +0000</resolved>
                                    <version>3.0.2</version>
                                                    <component>WiredTiger</component>
                                        <votes>0</votes>
                                    <watches>38</watches>
                                                                                                                <comments>
                            <comment id="945524" author="dan@10gen.com" created="Fri, 19 Jun 2015 14:44:45 +0000"  >&lt;p&gt;Resolving this issue as a duplicate of &lt;a href=&quot;https://jira.mongodb.org/browse/DOCS-5506&quot; title=&quot;Recommend use of XFS&quot; class=&quot;issue-link&quot; data-issue-key=&quot;DOCS-5506&quot;&gt;&lt;del&gt;DOCS-5506&lt;/del&gt;&lt;/a&gt;.  Production notes section has been updated to reflect the recommendation to use xfs.&lt;/p&gt;</comment>
                            <comment id="945498" author="bruce.lucas@10gen.com" created="Fri, 19 Jun 2015 14:26:52 +0000"  >&lt;p&gt;Wrote a standalone C program that does writes on some number of threads while doing an fdatasync, and demonstrated that the cause of the stalls in mongod was that writes to the file can block for the duration of the fdatasync.  Also observed that the writes would not necessarily stall immediately after the start of the fdatasync, but might only begin to stall after a few seconds. Using perf to probe context switch events was able to determine that this is the point where the writes block:&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;fs 30526 945970.213337: cs: &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;   ffffffff8172641f __schedule ([kernel.kallsyms])&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;   ffffffff817269d9 schedule ([kernel.kallsyms])&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;   ffffffff81287435 wait_transaction_locked ([kernel.kallsyms])&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;   ffffffff81287750 start_this_handle ([kernel.kallsyms])&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;   ffffffff81287c73 jbd2__journal_start ([kernel.kallsyms])&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;   ffffffff8126eb19 __ext4_journal_start_sb ([kernel.kallsyms])&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;   ffffffff8124735a ext4_dirty_inode ([kernel.kallsyms])&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;   ffffffff811e7cba __mark_inode_dirty ([kernel.kallsyms])&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;   ffffffff811d8cc1 update_time ([kernel.kallsyms])&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;   ffffffff811d8ed0 file_update_time ([kernel.kallsyms])&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;   ffffffff81150a40 __generic_file_aio_write ([kernel.kallsyms])&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;   ffffffff81150ce8 generic_file_aio_write ([kernel.kallsyms])&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;   ffffffff8123bce2 ext4_file_write ([kernel.kallsyms])&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;   ffffffff811bd7ea do_sync_write ([kernel.kallsyms])&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;   ffffffff811bdf74 vfs_write ([kernel.kallsyms])&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;   ffffffff811be9a9 sys_write ([kernel.kallsyms])&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;   ffffffff817330bd system_call_fastpath ([kernel.kallsyms])&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;       7fccf4d8235d [unknown] (/lib/x86_64-linux-gnu/libpthread-2.19.so)&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;           7fccf49cfec5 __libc_start_main (/lib/x86_64-linux-gnu/libc-2.19.so)&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;So it appears that the stall is related to ext4 journaling - apparently journaling is blocked while the fdatasync is in progress. The delay in stalling mentioned above is explained by the periodic journal commits: the writer thread is able to continue writing during fdatasync until the next journal commit; the default commit interval is 5 seconds, and indeed observed that the writes might be able to continue up to 5 seconds after the start of the fdatasync.&lt;/p&gt;

&lt;p&gt;Since the stalls occur in ext4-specific code, and are related to periodic journal commits, we can avoid the stalls, both in the test program and in mongod, by either&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;using XFS&lt;/li&gt;
	&lt;li&gt;mounting the EXT4 filesystem with a large commit interval (-o commit=largenumber) to effectively disable periodic journal commits. Note: this is safe for mongod because it ensures durability by doing fdatasyncs at appropriate times, but it dangerous with regard durability for typical programs that might happen to be using the same filesystem.&lt;/li&gt;
&lt;/ul&gt;
</comment>
                            <comment id="913274" author="bruce.lucas@10gen.com" created="Wed, 13 May 2015 20:11:08 +0000"  >&lt;p&gt;&lt;a href=&quot;https://jira.mongodb.org/secure/ViewProfile.jspa?name=michael.cahill&quot; class=&quot;user-hover&quot; rel=&quot;michael.cahill&quot;&gt;michael.cahill&lt;/a&gt;, tried master as of yesterday&apos;s nightly build.&lt;br/&gt;
YCSB 50/50, 10M docs 10 fields, 20 GB cache, 20 threads&lt;/p&gt;

&lt;ul&gt;
	&lt;li&gt;master indeed seems to fix the issue during the &quot;transaction pinned&quot; phase (&lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-18315&quot; title=&quot;Throughput drop during transaction pinned phase of checkpoints under WiredTiger&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-18315&quot;&gt;&lt;del&gt;SERVER-18315&lt;/del&gt;&lt;/a&gt;)&lt;/li&gt;
	&lt;li&gt;the fdatasync stall (this ticket) can be fixed by in addition either
	&lt;ul&gt;
		&lt;li&gt;using ext4 with -o commit=largenumber mount option, or&lt;/li&gt;
		&lt;li&gt;using xfs&lt;/li&gt;
	&lt;/ul&gt;
	&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;&lt;b&gt;3.0.2&lt;/b&gt;&lt;br/&gt;
&lt;span class=&quot;image-wrap&quot; style=&quot;&quot;&gt;&lt;img src=&quot;https://jira.mongodb.org/secure/attachment/74234/74234_try-23.png&quot; width=&quot;900&quot; style=&quot;border: 0px solid black&quot; /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;shows both &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-18315&quot; title=&quot;Throughput drop during transaction pinned phase of checkpoints under WiredTiger&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-18315&quot;&gt;&lt;del&gt;SERVER-18315&lt;/del&gt;&lt;/a&gt; (C-D) and this ticket (B-C, D-E)&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;&lt;b&gt;MASTER, EXT4&lt;/b&gt;&lt;br/&gt;
&lt;span class=&quot;image-wrap&quot; style=&quot;&quot;&gt;&lt;img src=&quot;https://jira.mongodb.org/secure/attachment/74235/74235_try-25.png&quot; width=&quot;900&quot; style=&quot;border: 0px solid black&quot; /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;fixes &lt;a href=&quot;https://jira.mongodb.org/browse/SERVER-18315&quot; title=&quot;Throughput drop during transaction pinned phase of checkpoints under WiredTiger&quot; class=&quot;issue-link&quot; data-issue-key=&quot;SERVER-18315&quot;&gt;&lt;del&gt;SERVER-18315&lt;/del&gt;&lt;/a&gt; (C-D)&lt;/li&gt;
	&lt;li&gt;fdatasync stalls (this ticket, B-C, D-E) remain&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;&lt;b&gt;MASTER, EXT4, BUT DISABLE EXT4 TIMED JOURNAL COMMITS (-o commit=... option)&lt;/b&gt;&lt;br/&gt;
&lt;span class=&quot;image-wrap&quot; style=&quot;&quot;&gt;&lt;img src=&quot;https://jira.mongodb.org/secure/attachment/74236/74236_try-26.png&quot; width=&quot;900&quot; style=&quot;border: 0px solid black&quot; /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;fixes fdatasync stalls&lt;/li&gt;
&lt;/ul&gt;


&lt;p&gt;&lt;b&gt;MASTER, XFS&lt;/b&gt;&lt;br/&gt;
&lt;span class=&quot;image-wrap&quot; style=&quot;&quot;&gt;&lt;img src=&quot;https://jira.mongodb.org/secure/attachment/74237/74237_try-29.png&quot; width=&quot;900&quot; style=&quot;border: 0px solid black&quot; /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;ul&gt;
	&lt;li&gt;also fixes fdatasync stalls&lt;/li&gt;
&lt;/ul&gt;
</comment>
                    </comments>
                <issuelinks>
                            <issuelinktype id="10011">
                    <name>Depends</name>
                                            <outwardlinks description="depends on">
                                        <issuelink>
            <issuekey id="205939">WT-1941</issuekey>
        </issuelink>
                            </outwardlinks>
                                                        </issuelinktype>
                            <issuelinktype id="10320">
                    <name>Documented</name>
                                            <outwardlinks description="documents">
                                                        </outwardlinks>
                                                        </issuelinktype>
                            <issuelinktype id="10010">
                    <name>Duplicate</name>
                                            <outwardlinks description="duplicates">
                                        <issuelink>
            <issuekey id="207092">DOCS-5506</issuekey>
        </issuelink>
                            </outwardlinks>
                                                        </issuelinktype>
                            <issuelinktype id="10012">
                    <name>Related</name>
                                            <outwardlinks description="related to">
                                        <issuelink>
            <issuekey id="205976">SERVER-18629</issuekey>
        </issuelink>
            <issuelink>
            <issuekey id="206745">SERVER-18674</issuekey>
        </issuelink>
            <issuelink>
            <issuekey id="263500">DOCS-7104</issuekey>
        </issuelink>
                            </outwardlinks>
                                                                <inwardlinks description="is related to">
                                        <issuelink>
            <issuekey id="201914">SERVER-18315</issuekey>
        </issuelink>
            <issuelink>
            <issuekey id="265264">SERVER-22606</issuekey>
        </issuelink>
                            </inwardlinks>
                                    </issuelinktype>
                    </issuelinks>
                <attachments>
                            <attachment id="74500" name="count=1000000.png" size="10643" author="keith.bostic@mongodb.com" created="Fri, 15 May 2015 14:19:33 +0000"/>
                            <attachment id="74315" name="lz4.png" size="8848" author="keith.bostic@mongodb.com" created="Thu, 14 May 2015 12:38:15 +0000"/>
                            <attachment id="74316" name="snappy.png" size="11037" author="keith.bostic@mongodb.com" created="Thu, 14 May 2015 12:38:15 +0000"/>
                            <attachment id="72796" name="try-13.png" size="148523" author="bruce.lucas@mongodb.com" created="Mon, 4 May 2015 19:51:54 +0000"/>
                            <attachment id="72903" name="try-14.png" size="107518" author="bruce.lucas@mongodb.com" created="Tue, 5 May 2015 15:29:42 +0000"/>
                            <attachment id="73323" name="try-16.png" size="66627" author="bruce.lucas@mongodb.com" created="Thu, 7 May 2015 13:47:28 +0000"/>
                            <attachment id="74047" name="try-21.png" size="145610" author="bruce.lucas@mongodb.com" created="Tue, 12 May 2015 20:21:22 +0000"/>
                            <attachment id="74234" name="try-23.png" size="117154" author="bruce.lucas@mongodb.com" created="Wed, 13 May 2015 20:08:32 +0000"/>
                            <attachment id="74235" name="try-25.png" size="118447" author="bruce.lucas@mongodb.com" created="Wed, 13 May 2015 20:08:32 +0000"/>
                            <attachment id="74236" name="try-26.png" size="116569" author="bruce.lucas@mongodb.com" created="Wed, 13 May 2015 20:09:12 +0000"/>
                            <attachment id="74237" name="try-29.png" size="119894" author="bruce.lucas@mongodb.com" created="Wed, 13 May 2015 20:09:12 +0000"/>
                            <attachment id="75251" name="try-30.png" size="78792" author="bruce.lucas@mongodb.com" created="Thu, 21 May 2015 18:09:17 +0000"/>
                            <attachment id="75252" name="try-33.png" size="63765" author="bruce.lucas@mongodb.com" created="Thu, 21 May 2015 18:09:17 +0000"/>
                            <attachment id="75376" name="try-34.png" size="61820" author="bruce.lucas@mongodb.com" created="Fri, 22 May 2015 12:24:27 +0000"/>
                            <attachment id="75405" name="try-35.png" size="64609" author="bruce.lucas@mongodb.com" created="Fri, 22 May 2015 15:28:32 +0000"/>
                            <attachment id="75406" name="try-36.png" size="64944" author="bruce.lucas@mongodb.com" created="Fri, 22 May 2015 15:28:32 +0000"/>
                    </attachments>
                <subtasks>
                    </subtasks>
                <customfields>
                                                <customfield id="customfield_10050" key="com.atlassian.jira.toolkit:comments">
                        <customfieldname># Replies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>3.0</customfieldvalue>
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        <customfield id="customfield_13552" key="com.go2group.jira.plugin.crm:crm_generic_field">
                        <customfieldname>Case</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue><![CDATA[[500A000000VmzNVIAZ, 500A000000Xz6QEIAZ, 5002K00000g4SbCQAU, 5006R00001xJQvgQAG]]]></customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                                                                                                            <customfield id="customfield_10055" key="com.atlassian.jira.ext.charting:firstresponsedate">
                        <customfieldname>Date of 1st Reply</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>Tue, 5 May 2015 18:48:45 +0000</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_10052" key="com.atlassian.jira.toolkit:dayslastcommented">
                        <customfieldname>Days since reply</customfieldname>
                        <customfieldvalues>
                                        8 years, 34 weeks, 5 days ago
    
                        </customfieldvalues>
                    </customfield>
                                                                <customfield id="customfield_18254" key="com.onresolve.jira.groovy.groovyrunner:scripted-field">
                        <customfieldname>Dependencies</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue><![CDATA[<s><a href='https://jira.mongodb.org/browse/WT-1941'>WT-1941</a></s>, <s><a href='https://jira.mongodb.org/browse/HELP-1145'>HELP-1145</a></s>]]></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_11151" key="com.atlassian.jira.toolkit:LastCommentDate">
                        <customfieldname>Last public comment date</customfieldname>
                        <customfieldvalues>
                            8 years, 34 weeks, 5 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>bruce.lucas@mongodb.com</customfieldvalue>
            <customfieldvalue>dan@mongodb.com</customfieldvalue>
            <customfieldvalue>ramon.fernandez@mongodb.com</customfieldvalue>
    
                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                                                                        <customfield id="customfield_14254" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Product Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>1|hrl6u7:</customfieldvalue>

                        </customfieldvalues>
                    </customfield>
                                                                                                                                                                                <customfield id="customfield_12550" key="com.pyxis.greenhopper.jira:gh-lexo-rank">
                        <customfieldname>Rank</customfieldname>
                        <customfieldvalues>
                            <customfieldvalue>2|hs90jz:</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_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|hrllpb:</customfieldvalue>

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