<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head> 
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 
        <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0"> 
        <base href="https://jira.qos.ch"> 
        <title>Message Title</title> 
    </head> 
    <body class="jira" style="color: #333333; font-family: Arial, sans-serif; font-size: 14px; line-height: 1.429"> 
        <table id="background-table" cellpadding="0" cellspacing="0" width="100%" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt; background-color: #f5f5f5; border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt" bgcolor="#f5f5f5"> 
            <!-- header here --> 
            <tbody>
                <tr> 
                    <td id="header-pattern-container" style="padding: 0px; border-collapse: collapse; padding: 10px 20px"> 
                        <table id="header-pattern" cellspacing="0" cellpadding="0" border="0" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt"> 
                            <tbody>
                                <tr> 
                                    <td id="header-avatar-image-container" valign="top" style="padding: 0px; border-collapse: collapse; vertical-align: top; width: 32px; padding-right: 8px" width="32"> <img id="header-avatar-image" class="image_fix" src="cid:jira-generated-image-avatar-5b9df442-ea39-47ad-8a34-06f470fe569b" height="32" width="32" border="0" style="border-radius: 3px; vertical-align: top"> </td> 
                                    <td id="header-text-container" valign="middle" style="padding: 0px; border-collapse: collapse; vertical-align: middle; font-family: Arial, sans-serif; font-size: 14px; line-height: 20px; mso-line-height-rule: exactly; mso-text-raise: 1px"> <a class="user-hover" rel="ceki" id="email_ceki" href="https://jira.qos.ch/secure/ViewProfile.jspa?name=ceki" style="color:#3b73af;; color: #3b73af; text-decoration: none">Ceki Gülcü</a> <strong>commented</strong> on <a href="https://jira.qos.ch/browse/LOGBACK-1279" style="color: #3b73af; text-decoration: none"><img src="cid:jira-generated-image-avatar-0852dbd5-d6ec-4234-813a-d90fa538e70e" height="16" width="16" border="0" align="absmiddle" alt="Bug"> LOGBACK-1279</a> </td> 
                                </tr> 
                            </tbody>
                        </table> </td> 
                </tr> 
                <tr> 
                    <td id="email-content-container" style="padding: 0px; border-collapse: collapse; padding: 0 20px"> 
                        <table id="email-content-table" cellspacing="0" cellpadding="0" border="0" width="100%" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt; border-spacing: 0; border-collapse: separate"> 
                            <tbody>
                                <tr> 
                                    <!-- there needs to be content in the cell for it to render in some clients --> 
                                    <td class="email-content-rounded-top mobile-expand" style="padding: 0px; border-collapse: collapse; color: #ffffff; padding: 0 15px 0 16px; height: 15px; background-color: #ffffff; border-left: 1px solid #cccccc; border-top: 1px solid #cccccc; border-right: 1px solid #cccccc; border-bottom: 0; border-top-right-radius: 5px; border-top-left-radius: 5px; height: 10px; line-height: 10px; padding: 0 15px 0 16px; mso-line-height-rule: exactly" height="10" bgcolor="#ffffff"> </td> 
                                </tr> 
                                <tr> 
                                    <td class="email-content-main mobile-expand " style="padding: 0px; border-collapse: collapse; border-left: 1px solid #cccccc; border-right: 1px solid #cccccc; border-top: 0; border-bottom: 0; padding: 0 15px 0 16px; background-color: #ffffff" bgcolor="#ffffff"> 
                                        <table class="page-title-pattern" cellspacing="0" cellpadding="0" border="0" width="100%" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt"> 
                                            <tbody>
                                                <tr> 
                                                    <td style="vertical-align: top;; padding: 0px; border-collapse: collapse; padding-right: 5px; font-size: 20px; line-height: 30px; mso-line-height-rule: exactly" class="page-title-pattern-header-container"> <span class="page-title-pattern-header" style="font-family: Arial, sans-serif; padding: 0; font-size: 20px; line-height: 30px; mso-text-raise: 2px; mso-line-height-rule: exactly; vertical-align: middle"> <a href="https://jira.qos.ch/browse/LOGBACK-1279" style="color: #3b73af; text-decoration: none">Re: Async appenders do not scale well across multiple threads</a> </span> </td> 
                                                </tr> 
                                            </tbody>
                                        </table> </td> 
                                </tr> 
                                <tr> 
                                    <td id="text-paragraph-pattern-top" class="email-content-main mobile-expand  comment-top-pattern" style="padding: 0px; border-collapse: collapse; border-left: 1px solid #cccccc; border-right: 1px solid #cccccc; border-top: 0; border-bottom: 0; padding: 0 15px 0 16px; background-color: #ffffff; border-bottom: none; padding-bottom: 0" bgcolor="#ffffff"> 
                                        <table class="text-paragraph-pattern" cellspacing="0" cellpadding="0" border="0" width="100%" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt; font-family: Arial, sans-serif; font-size: 14px; line-height: 20px; mso-line-height-rule: exactly; mso-text-raise: 2px"> 
                                            <tbody>
                                                <tr> 
                                                    <td class="text-paragraph-pattern-container mobile-resize-text " style="padding: 0px; border-collapse: collapse; padding: 0 0 10px 0"> <p style="margin: 10px 0 0 0; margin-top: 0">I have updated <a href="https://github.com/ceki/logback-perf" class="external-link" rel="nofollow" style="color: #3b73af; text-decoration: none">logback-perf</a> and added coverage the for async case. The results on my machine are published <a href="https://docs.google.com/spreadsheets/d/1cpb5D7qnyye4W0RTlHUnXedYK98catNZytYIu5D91m0/edit#gid=1763660342" class="external-link" rel="nofollow" style="color: #3b73af; text-decoration: none">as a Google Sheet</a>. As you point out, logback <tt>AsyncAppender</tt> performance degrades as the thread count increases. I was particularly surprised to see that Logback's <tt>AsyncAppender</tt> performance is worse that that of log4j's <tt>AsyncAppender</tt>, code that was written with JDK 1.2. </p> <p style="margin: 10px 0 0 0">Given that logback's <tt>AsyncAppender</tt> relies heavily on <tt>java.util.concurrent.ArrayBlockingQueue</tt>, unless I am missing something, the results incriminate the latter rather than the former.</p> <p style="margin: 10px 0 0 0">I am still uncomfortable with reaching any conclusions. First, as you know, a lossy <tt>AsyncAppender</tt> has stellar performance. More importantly, a real application will do more than just log in a loop. Thus, in a real application, <tt>AsyncAppender</tt> will have some breathing room. I'll try to simulate this situation with a new benchmark.</p> </td> 
                                                </tr> 
                                            </tbody>
                                        </table> </td> 
                                </tr> 
                                <tr> 
                                    <td class="email-content-main mobile-expand " style="padding: 0px; border-collapse: collapse; border-left: 1px solid #cccccc; border-right: 1px solid #cccccc; border-top: 0; border-bottom: 0; padding: 0 15px 0 16px; background-color: #ffffff" bgcolor="#ffffff"> 
                                        <table id="actions-pattern" cellspacing="0" cellpadding="0" border="0" width="100%" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt; font-family: Arial, sans-serif; font-size: 14px; line-height: 20px; mso-line-height-rule: exactly; mso-text-raise: 1px"> 
                                            <tbody>
                                                <tr> 
                                                    <td id="actions-pattern-container" valign="middle" style="padding: 0px; border-collapse: collapse; padding: 10px 0 10px 24px; vertical-align: middle; padding-left: 0"> 
                                                        <table align="left" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt"> 
                                                            <tbody>
                                                                <tr> 
                                                                    <td class="actions-pattern-action-icon-container" style="padding: 0px; border-collapse: collapse; font-family: Arial, sans-serif; font-size: 14px; line-height: 20px; mso-line-height-rule: exactly; mso-text-raise: 0px; vertical-align: middle"> <a href="https://jira.qos.ch/browse/LOGBACK-1279#add-comment" target="_blank" title="Add Comment" style="color: #3b73af; text-decoration: none"> <img class="actions-pattern-action-icon-image" src="cid:jira-generated-image-static-comment-icon-1de28503-16ff-4f7e-b1e6-8d148304647b" alt="Add Comment" title="Add Comment" height="16" width="16" border="0" style="vertical-align: middle"> </a> </td> 
                                                                    <td class="actions-pattern-action-text-container" style="padding: 0px; border-collapse: collapse; font-family: Arial, sans-serif; font-size: 14px; line-height: 20px; mso-line-height-rule: exactly; mso-text-raise: 4px; padding-left: 5px"> <a href="https://jira.qos.ch/browse/LOGBACK-1279#add-comment" target="_blank" title="Add Comment" style="color: #3b73af; text-decoration: none">Add Comment</a> </td> 
                                                                </tr> 
                                                            </tbody>
                                                        </table> </td> 
                                                </tr> 
                                            </tbody>
                                        </table> </td> 
                                </tr> 
                                <!-- there needs to be content in the cell for it to render in some clients --> 
                                <tr> 
                                    <td class="email-content-rounded-bottom mobile-expand" style="padding: 0px; border-collapse: collapse; color: #ffffff; padding: 0 15px 0 16px; height: 5px; line-height: 5px; background-color: #ffffff; border-top: 0; border-left: 1px solid #cccccc; border-bottom: 1px solid #cccccc; border-right: 1px solid #cccccc; border-bottom-right-radius: 5px; border-bottom-left-radius: 5px; mso-line-height-rule: exactly" height="5" bgcolor="#ffffff"> </td> 
                                </tr> 
                            </tbody>
                        </table> </td> 
                </tr> 
                <tr> 
                    <td id="footer-pattern" style="padding: 0px; border-collapse: collapse; padding: 12px 20px"> 
                        <table id="footer-pattern-container" cellspacing="0" cellpadding="0" border="0" style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt"> 
                            <tbody>
                                <tr> 
                                    <td id="footer-pattern-text" class="mobile-resize-text" width="100%" style="padding: 0px; border-collapse: collapse; color: #999999; font-size: 12px; line-height: 18px; font-family: Arial, sans-serif; mso-line-height-rule: exactly; mso-text-raise: 2px"> This message was sent by Atlassian JIRA <span id="footer-build-information">(v7.3.1#73012-<span title="68837e38d8ed1b069612405186dcdceed665bb39" data-commit-id="68837e38d8ed1b069612405186dcdceed665bb39}">sha1:68837e3</span>)</span> </td> 
                                    <td id="footer-pattern-logo-desktop-container" valign="top" style="padding: 0px; border-collapse: collapse; padding-left: 20px; vertical-align: top"> 
                                        <table style="border-collapse: collapse; mso-table-lspace: 0pt; mso-table-rspace: 0pt"> 
                                            <tbody>
                                                <tr> 
                                                    <td id="footer-pattern-logo-desktop-padding" style="padding: 0px; border-collapse: collapse; padding-top: 3px"> <img id="footer-pattern-logo-desktop" src="cid:jira-generated-image-static-footer-desktop-logo-fe7a5b51-7781-4d63-b788-c3f865faeb02" alt="Atlassian logo" title="Atlassian logo" width="169" height="36" class="image_fix"> </td> 
                                                </tr> 
                                            </tbody>
                                        </table> </td> 
                                </tr> 
                            </tbody>
                        </table> </td> 
                </tr> 
            </tbody>
        </table>   
    </body>
</html>