1514 lines
72 KiB
HTML
1514 lines
72 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="en">
|
|
<head>
|
|
<meta charset="UTF-8">
|
|
<!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta name="generator" content="Asciidoctor 1.5.3">
|
|
<title>Spring Cloud Sleuth</title>
|
|
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700">
|
|
<style>
|
|
/* Asciidoctor default stylesheet | MIT License | http://asciidoctor.org */
|
|
/* Remove comment around @import statement below when using as a custom stylesheet */
|
|
/*@import "https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700";*/
|
|
article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
|
|
audio,canvas,video{display:inline-block}
|
|
audio:not([controls]){display:none;height:0}
|
|
[hidden],template{display:none}
|
|
script{display:none!important}
|
|
html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}
|
|
body{margin:0}
|
|
a{background:transparent}
|
|
a:focus{outline:thin dotted}
|
|
a:active,a:hover{outline:0}
|
|
h1{font-size:2em;margin:.67em 0}
|
|
abbr[title]{border-bottom:1px dotted}
|
|
b,strong{font-weight:bold}
|
|
dfn{font-style:italic}
|
|
hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}
|
|
mark{background:#ff0;color:#000}
|
|
code,kbd,pre,samp{font-family:monospace;font-size:1em}
|
|
pre{white-space:pre-wrap}
|
|
q{quotes:"\201C" "\201D" "\2018" "\2019"}
|
|
small{font-size:80%}
|
|
sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
|
|
sup{top:-.5em}
|
|
sub{bottom:-.25em}
|
|
img{border:0}
|
|
svg:not(:root){overflow:hidden}
|
|
figure{margin:0}
|
|
fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}
|
|
legend{border:0;padding:0}
|
|
button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}
|
|
button,input{line-height:normal}
|
|
button,select{text-transform:none}
|
|
button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
|
|
button[disabled],html input[disabled]{cursor:default}
|
|
input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}
|
|
input[type="search"]{-webkit-appearance:textfield;-moz-box-sizing:content-box;-webkit-box-sizing:content-box;box-sizing:content-box}
|
|
input[type="search"]::-webkit-search-cancel-button,input[type="search"]::-webkit-search-decoration{-webkit-appearance:none}
|
|
button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
|
|
textarea{overflow:auto;vertical-align:top}
|
|
table{border-collapse:collapse;border-spacing:0}
|
|
*,*:before,*:after{-moz-box-sizing:border-box;-webkit-box-sizing:border-box;box-sizing:border-box}
|
|
html,body{font-size:100%}
|
|
body{background:#fff;color:rgba(0,0,0,.8);padding:0;margin:0;font-family:"Noto Serif","DejaVu Serif",serif;font-weight:400;font-style:normal;line-height:1;position:relative;cursor:auto}
|
|
a:hover{cursor:pointer}
|
|
img,object,embed{max-width:100%;height:auto}
|
|
object,embed{height:100%}
|
|
img{-ms-interpolation-mode:bicubic}
|
|
.left{float:left!important}
|
|
.right{float:right!important}
|
|
.text-left{text-align:left!important}
|
|
.text-right{text-align:right!important}
|
|
.text-center{text-align:center!important}
|
|
.text-justify{text-align:justify!important}
|
|
.hide{display:none}
|
|
body{-webkit-font-smoothing:antialiased}
|
|
img,object,svg{display:inline-block;vertical-align:middle}
|
|
textarea{height:auto;min-height:50px}
|
|
select{width:100%}
|
|
.center{margin-left:auto;margin-right:auto}
|
|
.spread{width:100%}
|
|
p.lead,.paragraph.lead>p,#preamble>.sectionbody>.paragraph:first-of-type p{font-size:1.21875em;line-height:1.6}
|
|
.subheader,.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{line-height:1.45;color:#7a2518;font-weight:400;margin-top:0;margin-bottom:.25em}
|
|
div,dl,dt,dd,ul,ol,li,h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6,pre,form,p,blockquote,th,td{margin:0;padding:0;direction:ltr}
|
|
a{color:#2156a5;text-decoration:underline;line-height:inherit}
|
|
a:hover,a:focus{color:#1d4b8f}
|
|
a img{border:none}
|
|
p{font-family:inherit;font-weight:400;font-size:1em;line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility}
|
|
p aside{font-size:.875em;line-height:1.35;font-style:italic}
|
|
h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{font-family:"Open Sans","DejaVu Sans",sans-serif;font-weight:300;font-style:normal;color:#ba3925;text-rendering:optimizeLegibility;margin-top:1em;margin-bottom:.5em;line-height:1.0125em}
|
|
h1 small,h2 small,h3 small,#toctitle small,.sidebarblock>.content>.title small,h4 small,h5 small,h6 small{font-size:60%;color:#e99b8f;line-height:0}
|
|
h1{font-size:2.125em}
|
|
h2{font-size:1.6875em}
|
|
h3,#toctitle,.sidebarblock>.content>.title{font-size:1.375em}
|
|
h4,h5{font-size:1.125em}
|
|
h6{font-size:1em}
|
|
hr{border:solid #ddddd8;border-width:1px 0 0;clear:both;margin:1.25em 0 1.1875em;height:0}
|
|
em,i{font-style:italic;line-height:inherit}
|
|
strong,b{font-weight:bold;line-height:inherit}
|
|
small{font-size:60%;line-height:inherit}
|
|
code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
|
|
ul,ol,dl{font-size:1em;line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit}
|
|
ul,ol,ul.no-bullet,ol.no-bullet{margin-left:1.5em}
|
|
ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0;font-size:1em}
|
|
ul.square li ul,ul.circle li ul,ul.disc li ul{list-style:inherit}
|
|
ul.square{list-style-type:square}
|
|
ul.circle{list-style-type:circle}
|
|
ul.disc{list-style-type:disc}
|
|
ul.no-bullet{list-style:none}
|
|
ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
|
|
dl dt{margin-bottom:.3125em;font-weight:bold}
|
|
dl dd{margin-bottom:1.25em}
|
|
abbr,acronym{text-transform:uppercase;font-size:90%;color:rgba(0,0,0,.8);border-bottom:1px dotted #ddd;cursor:help}
|
|
abbr{text-transform:none}
|
|
blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd}
|
|
blockquote cite{display:block;font-size:.9375em;color:rgba(0,0,0,.6)}
|
|
blockquote cite:before{content:"\2014 \0020"}
|
|
blockquote cite a,blockquote cite a:visited{color:rgba(0,0,0,.6)}
|
|
blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)}
|
|
@media only screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2}
|
|
h1{font-size:2.75em}
|
|
h2{font-size:2.3125em}
|
|
h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em}
|
|
h4{font-size:1.4375em}}
|
|
table{background:#fff;margin-bottom:1.25em;border:solid 1px #dedede}
|
|
table thead,table tfoot{background:#f7f8f7;font-weight:bold}
|
|
table thead tr th,table thead tr td,table tfoot tr th,table tfoot tr td{padding:.5em .625em .625em;font-size:inherit;color:rgba(0,0,0,.8);text-align:left}
|
|
table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)}
|
|
table tr.even,table tr.alt,table tr:nth-of-type(even){background:#f8f8f7}
|
|
table thead tr th,table tfoot tr th,table tbody tr td,table tr td,table tfoot tr td{display:table-cell;line-height:1.6}
|
|
body{tab-size:4}
|
|
h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em}
|
|
h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400}
|
|
.clearfix:before,.clearfix:after,.float-group:before,.float-group:after{content:" ";display:table}
|
|
.clearfix:after,.float-group:after{clear:both}
|
|
*:not(pre)>code{font-size:.9375em;font-style:normal!important;letter-spacing:0;padding:.1em .5ex;word-spacing:-.15em;background-color:#f7f7f8;-webkit-border-radius:4px;border-radius:4px;line-height:1.45;text-rendering:optimizeSpeed}
|
|
pre,pre>code{line-height:1.45;color:rgba(0,0,0,.9);font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;text-rendering:optimizeSpeed}
|
|
.keyseq{color:rgba(51,51,51,.8)}
|
|
kbd{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;display:inline-block;color:rgba(0,0,0,.8);font-size:.65em;line-height:1.45;background-color:#f7f7f7;border:1px solid #ccc;-webkit-border-radius:3px;border-radius:3px;-webkit-box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em white inset;box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em #fff inset;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap}
|
|
.keyseq kbd:first-child{margin-left:0}
|
|
.keyseq kbd:last-child{margin-right:0}
|
|
.menuseq,.menu{color:rgba(0,0,0,.8)}
|
|
b.button:before,b.button:after{position:relative;top:-1px;font-weight:400}
|
|
b.button:before{content:"[";padding:0 3px 0 2px}
|
|
b.button:after{content:"]";padding:0 2px 0 3px}
|
|
p a>code:hover{color:rgba(0,0,0,.9)}
|
|
#header,#content,#footnotes,#footer{width:100%;margin-left:auto;margin-right:auto;margin-top:0;margin-bottom:0;max-width:62.5em;*zoom:1;position:relative;padding-left:.9375em;padding-right:.9375em}
|
|
#header:before,#header:after,#content:before,#content:after,#footnotes:before,#footnotes:after,#footer:before,#footer:after{content:" ";display:table}
|
|
#header:after,#content:after,#footnotes:after,#footer:after{clear:both}
|
|
#content{margin-top:1.25em}
|
|
#content:before{content:none}
|
|
#header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0}
|
|
#header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #ddddd8}
|
|
#header>h1:only-child,body.toc2 #header>h1:nth-last-child(2){border-bottom:1px solid #ddddd8;padding-bottom:8px}
|
|
#header .details{border-bottom:1px solid #ddddd8;line-height:1.45;padding-top:.25em;padding-bottom:.25em;padding-left:.25em;color:rgba(0,0,0,.6);display:-ms-flexbox;display:-webkit-flex;display:flex;-ms-flex-flow:row wrap;-webkit-flex-flow:row wrap;flex-flow:row wrap}
|
|
#header .details span:first-child{margin-left:-.125em}
|
|
#header .details span.email a{color:rgba(0,0,0,.85)}
|
|
#header .details br{display:none}
|
|
#header .details br+span:before{content:"\00a0\2013\00a0"}
|
|
#header .details br+span.author:before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)}
|
|
#header .details br+span#revremark:before{content:"\00a0|\00a0"}
|
|
#header #revnumber{text-transform:capitalize}
|
|
#header #revnumber:after{content:"\00a0"}
|
|
#content>h1:first-child:not([class]){color:rgba(0,0,0,.85);border-bottom:1px solid #ddddd8;padding-bottom:8px;margin-top:0;padding-top:1rem;margin-bottom:1.25rem}
|
|
#toc{border-bottom:1px solid #efefed;padding-bottom:.5em}
|
|
#toc>ul{margin-left:.125em}
|
|
#toc ul.sectlevel0>li>a{font-style:italic}
|
|
#toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0}
|
|
#toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none}
|
|
#toc li{line-height:1.3334;margin-top:.3334em}
|
|
#toc a{text-decoration:none}
|
|
#toc a:active{text-decoration:underline}
|
|
#toctitle{color:#7a2518;font-size:1.2em}
|
|
@media only screen and (min-width:768px){#toctitle{font-size:1.375em}
|
|
body.toc2{padding-left:15em;padding-right:0}
|
|
#toc.toc2{margin-top:0!important;background-color:#f8f8f7;position:fixed;width:15em;left:0;top:0;border-right:1px solid #efefed;border-top-width:0!important;border-bottom-width:0!important;z-index:1000;padding:1.25em 1em;height:100%;overflow:auto}
|
|
#toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em}
|
|
#toc.toc2>ul{font-size:.9em;margin-bottom:0}
|
|
#toc.toc2 ul ul{margin-left:0;padding-left:1em}
|
|
#toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em}
|
|
body.toc2.toc-right{padding-left:0;padding-right:15em}
|
|
body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #efefed;left:auto;right:0}}
|
|
@media only screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0}
|
|
#toc.toc2{width:20em}
|
|
#toc.toc2 #toctitle{font-size:1.375em}
|
|
#toc.toc2>ul{font-size:.95em}
|
|
#toc.toc2 ul ul{padding-left:1.25em}
|
|
body.toc2.toc-right{padding-left:0;padding-right:20em}}
|
|
#content #toc{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
|
|
#content #toc>:first-child{margin-top:0}
|
|
#content #toc>:last-child{margin-bottom:0}
|
|
#footer{max-width:100%;background-color:rgba(0,0,0,.8);padding:1.25em}
|
|
#footer-text{color:rgba(255,255,255,.8);line-height:1.44}
|
|
.sect1{padding-bottom:.625em}
|
|
@media only screen and (min-width:768px){.sect1{padding-bottom:1.25em}}
|
|
.sect1+.sect1{border-top:1px solid #efefed}
|
|
#content h1>a.anchor,h2>a.anchor,h3>a.anchor,#toctitle>a.anchor,.sidebarblock>.content>.title>a.anchor,h4>a.anchor,h5>a.anchor,h6>a.anchor{position:absolute;z-index:1001;width:1.5ex;margin-left:-1.5ex;display:block;text-decoration:none!important;visibility:hidden;text-align:center;font-weight:400}
|
|
#content h1>a.anchor:before,h2>a.anchor:before,h3>a.anchor:before,#toctitle>a.anchor:before,.sidebarblock>.content>.title>a.anchor:before,h4>a.anchor:before,h5>a.anchor:before,h6>a.anchor:before{content:"\00A7";font-size:.85em;display:block;padding-top:.1em}
|
|
#content h1:hover>a.anchor,#content h1>a.anchor:hover,h2:hover>a.anchor,h2>a.anchor:hover,h3:hover>a.anchor,#toctitle:hover>a.anchor,.sidebarblock>.content>.title:hover>a.anchor,h3>a.anchor:hover,#toctitle>a.anchor:hover,.sidebarblock>.content>.title>a.anchor:hover,h4:hover>a.anchor,h4>a.anchor:hover,h5:hover>a.anchor,h5>a.anchor:hover,h6:hover>a.anchor,h6>a.anchor:hover{visibility:visible}
|
|
#content h1>a.link,h2>a.link,h3>a.link,#toctitle>a.link,.sidebarblock>.content>.title>a.link,h4>a.link,h5>a.link,h6>a.link{color:#ba3925;text-decoration:none}
|
|
#content h1>a.link:hover,h2>a.link:hover,h3>a.link:hover,#toctitle>a.link:hover,.sidebarblock>.content>.title>a.link:hover,h4>a.link:hover,h5>a.link:hover,h6>a.link:hover{color:#a53221}
|
|
.audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em}
|
|
.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{text-rendering:optimizeLegibility;text-align:left;font-family:"Noto Serif","DejaVu Serif",serif;font-size:1rem;font-style:italic}
|
|
table.tableblock>caption.title{white-space:nowrap;overflow:visible;max-width:0}
|
|
.paragraph.lead>p,#preamble>.sectionbody>.paragraph:first-of-type p{color:rgba(0,0,0,.85)}
|
|
table.tableblock #preamble>.sectionbody>.paragraph:first-of-type p{font-size:inherit}
|
|
.admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
|
|
.admonitionblock>table td.icon{text-align:center;width:80px}
|
|
.admonitionblock>table td.icon img{max-width:none}
|
|
.admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
|
|
.admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #ddddd8;color:rgba(0,0,0,.6)}
|
|
.admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
|
|
.exampleblock>.content{border-style:solid;border-width:1px;border-color:#e6e6e6;margin-bottom:1.25em;padding:1.25em;background:#fff;-webkit-border-radius:4px;border-radius:4px}
|
|
.exampleblock>.content>:first-child{margin-top:0}
|
|
.exampleblock>.content>:last-child{margin-bottom:0}
|
|
.sidebarblock{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
|
|
.sidebarblock>:first-child{margin-top:0}
|
|
.sidebarblock>:last-child{margin-bottom:0}
|
|
.sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center}
|
|
.exampleblock>.content>:last-child>:last-child,.exampleblock>.content .olist>ol>li:last-child>:last-child,.exampleblock>.content .ulist>ul>li:last-child>:last-child,.exampleblock>.content .qlist>ol>li:last-child>:last-child,.sidebarblock>.content>:last-child>:last-child,.sidebarblock>.content .olist>ol>li:last-child>:last-child,.sidebarblock>.content .ulist>ul>li:last-child>:last-child,.sidebarblock>.content .qlist>ol>li:last-child>:last-child{margin-bottom:0}
|
|
.literalblock pre,.listingblock pre:not(.highlight),.listingblock pre[class="highlight"],.listingblock pre[class^="highlight "],.listingblock pre.CodeRay,.listingblock pre.prettyprint{background:#f7f7f8}
|
|
.sidebarblock .literalblock pre,.sidebarblock .listingblock pre:not(.highlight),.sidebarblock .listingblock pre[class="highlight"],.sidebarblock .listingblock pre[class^="highlight "],.sidebarblock .listingblock pre.CodeRay,.sidebarblock .listingblock pre.prettyprint{background:#f2f1f1}
|
|
.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{-webkit-border-radius:4px;border-radius:4px;word-wrap:break-word;padding:1em;font-size:.8125em}
|
|
.literalblock pre.nowrap,.literalblock pre[class].nowrap,.listingblock pre.nowrap,.listingblock pre[class].nowrap{overflow-x:auto;white-space:pre;word-wrap:normal}
|
|
@media only screen and (min-width:768px){.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{font-size:.90625em}}
|
|
@media only screen and (min-width:1280px){.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{font-size:1em}}
|
|
.literalblock.output pre{color:#f7f7f8;background-color:rgba(0,0,0,.9)}
|
|
.listingblock pre.highlightjs{padding:0}
|
|
.listingblock pre.highlightjs>code{padding:1em;-webkit-border-radius:4px;border-radius:4px}
|
|
.listingblock pre.prettyprint{border-width:0}
|
|
.listingblock>.content{position:relative}
|
|
.listingblock code[data-lang]:before{display:none;content:attr(data-lang);position:absolute;font-size:.75em;top:.425rem;right:.5rem;line-height:1;text-transform:uppercase;color:#999}
|
|
.listingblock:hover code[data-lang]:before{display:block}
|
|
.listingblock.terminal pre .command:before{content:attr(data-prompt);padding-right:.5em;color:#999}
|
|
.listingblock.terminal pre .command:not([data-prompt]):before{content:"$"}
|
|
table.pyhltable{border-collapse:separate;border:0;margin-bottom:0;background:none}
|
|
table.pyhltable td{vertical-align:top;padding-top:0;padding-bottom:0;line-height:1.45}
|
|
table.pyhltable td.code{padding-left:.75em;padding-right:0}
|
|
pre.pygments .lineno,table.pyhltable td:not(.code){color:#999;padding-left:0;padding-right:.5em;border-right:1px solid #ddddd8}
|
|
pre.pygments .lineno{display:inline-block;margin-right:.25em}
|
|
table.pyhltable .linenodiv{background:none!important;padding-right:0!important}
|
|
.quoteblock{margin:0 1em 1.25em 1.5em;display:table}
|
|
.quoteblock>.title{margin-left:-1.5em;margin-bottom:.75em}
|
|
.quoteblock blockquote,.quoteblock blockquote p{color:rgba(0,0,0,.85);font-size:1.15rem;line-height:1.75;word-spacing:.1em;letter-spacing:0;font-style:italic;text-align:justify}
|
|
.quoteblock blockquote{margin:0;padding:0;border:0}
|
|
.quoteblock blockquote:before{content:"\201c";float:left;font-size:2.75em;font-weight:bold;line-height:.6em;margin-left:-.6em;color:#7a2518;text-shadow:0 1px 2px rgba(0,0,0,.1)}
|
|
.quoteblock blockquote>.paragraph:last-child p{margin-bottom:0}
|
|
.quoteblock .attribution{margin-top:.5em;margin-right:.5ex;text-align:right}
|
|
.quoteblock .quoteblock{margin-left:0;margin-right:0;padding:.5em 0;border-left:3px solid rgba(0,0,0,.6)}
|
|
.quoteblock .quoteblock blockquote{padding:0 0 0 .75em}
|
|
.quoteblock .quoteblock blockquote:before{display:none}
|
|
.verseblock{margin:0 1em 1.25em 1em}
|
|
.verseblock pre{font-family:"Open Sans","DejaVu Sans",sans;font-size:1.15rem;color:rgba(0,0,0,.85);font-weight:300;text-rendering:optimizeLegibility}
|
|
.verseblock pre strong{font-weight:400}
|
|
.verseblock .attribution{margin-top:1.25rem;margin-left:.5ex}
|
|
.quoteblock .attribution,.verseblock .attribution{font-size:.9375em;line-height:1.45;font-style:italic}
|
|
.quoteblock .attribution br,.verseblock .attribution br{display:none}
|
|
.quoteblock .attribution cite,.verseblock .attribution cite{display:block;letter-spacing:-.025em;color:rgba(0,0,0,.6)}
|
|
.quoteblock.abstract{margin:0 0 1.25em 0;display:block}
|
|
.quoteblock.abstract blockquote,.quoteblock.abstract blockquote p{text-align:left;word-spacing:0}
|
|
.quoteblock.abstract blockquote:before,.quoteblock.abstract blockquote p:first-of-type:before{display:none}
|
|
table.tableblock{max-width:100%;border-collapse:separate}
|
|
table.tableblock td>.paragraph:last-child p>p:last-child,table.tableblock th>p:last-child,table.tableblock td>p:last-child{margin-bottom:0}
|
|
table.tableblock,th.tableblock,td.tableblock{border:0 solid #dedede}
|
|
table.grid-all th.tableblock,table.grid-all td.tableblock{border-width:0 1px 1px 0}
|
|
table.grid-all tfoot>tr>th.tableblock,table.grid-all tfoot>tr>td.tableblock{border-width:1px 1px 0 0}
|
|
table.grid-cols th.tableblock,table.grid-cols td.tableblock{border-width:0 1px 0 0}
|
|
table.grid-all *>tr>.tableblock:last-child,table.grid-cols *>tr>.tableblock:last-child{border-right-width:0}
|
|
table.grid-rows th.tableblock,table.grid-rows td.tableblock{border-width:0 0 1px 0}
|
|
table.grid-all tbody>tr:last-child>th.tableblock,table.grid-all tbody>tr:last-child>td.tableblock,table.grid-all thead:last-child>tr>th.tableblock,table.grid-rows tbody>tr:last-child>th.tableblock,table.grid-rows tbody>tr:last-child>td.tableblock,table.grid-rows thead:last-child>tr>th.tableblock{border-bottom-width:0}
|
|
table.grid-rows tfoot>tr>th.tableblock,table.grid-rows tfoot>tr>td.tableblock{border-width:1px 0 0 0}
|
|
table.frame-all{border-width:1px}
|
|
table.frame-sides{border-width:0 1px}
|
|
table.frame-topbot{border-width:1px 0}
|
|
th.halign-left,td.halign-left{text-align:left}
|
|
th.halign-right,td.halign-right{text-align:right}
|
|
th.halign-center,td.halign-center{text-align:center}
|
|
th.valign-top,td.valign-top{vertical-align:top}
|
|
th.valign-bottom,td.valign-bottom{vertical-align:bottom}
|
|
th.valign-middle,td.valign-middle{vertical-align:middle}
|
|
table thead th,table tfoot th{font-weight:bold}
|
|
tbody tr th{display:table-cell;line-height:1.6;background:#f7f8f7}
|
|
tbody tr th,tbody tr th p,tfoot tr th,tfoot tr th p{color:rgba(0,0,0,.8);font-weight:bold}
|
|
p.tableblock>code:only-child{background:none;padding:0}
|
|
p.tableblock{font-size:1em}
|
|
td>div.verse{white-space:pre}
|
|
ol{margin-left:1.75em}
|
|
ul li ol{margin-left:1.5em}
|
|
dl dd{margin-left:1.125em}
|
|
dl dd:last-child,dl dd:last-child>:last-child{margin-bottom:0}
|
|
ol>li p,ul>li p,ul dd,ol dd,.olist .olist,.ulist .ulist,.ulist .olist,.olist .ulist{margin-bottom:.625em}
|
|
ul.unstyled,ol.unnumbered,ul.checklist,ul.none{list-style-type:none}
|
|
ul.unstyled,ol.unnumbered,ul.checklist{margin-left:.625em}
|
|
ul.checklist li>p:first-child>.fa-square-o:first-child,ul.checklist li>p:first-child>.fa-check-square-o:first-child{width:1em;font-size:.85em}
|
|
ul.checklist li>p:first-child>input[type="checkbox"]:first-child{width:1em;position:relative;top:1px}
|
|
ul.inline{margin:0 auto .625em auto;margin-left:-1.375em;margin-right:0;padding:0;list-style:none;overflow:hidden}
|
|
ul.inline>li{list-style:none;float:left;margin-left:1.375em;display:block}
|
|
ul.inline>li>*{display:block}
|
|
.unstyled dl dt{font-weight:400;font-style:normal}
|
|
ol.arabic{list-style-type:decimal}
|
|
ol.decimal{list-style-type:decimal-leading-zero}
|
|
ol.loweralpha{list-style-type:lower-alpha}
|
|
ol.upperalpha{list-style-type:upper-alpha}
|
|
ol.lowerroman{list-style-type:lower-roman}
|
|
ol.upperroman{list-style-type:upper-roman}
|
|
ol.lowergreek{list-style-type:lower-greek}
|
|
.hdlist>table,.colist>table{border:0;background:none}
|
|
.hdlist>table>tbody>tr,.colist>table>tbody>tr{background:none}
|
|
td.hdlist1,td.hdlist2{vertical-align:top;padding:0 .625em}
|
|
td.hdlist1{font-weight:bold;padding-bottom:1.25em}
|
|
.literalblock+.colist,.listingblock+.colist{margin-top:-.5em}
|
|
.colist>table tr>td:first-of-type{padding:0 .75em;line-height:1}
|
|
.colist>table tr>td:last-of-type{padding:.25em 0}
|
|
.thumb,.th{line-height:0;display:inline-block;border:solid 4px #fff;-webkit-box-shadow:0 0 0 1px #ddd;box-shadow:0 0 0 1px #ddd}
|
|
.imageblock.left,.imageblock[style*="float: left"]{margin:.25em .625em 1.25em 0}
|
|
.imageblock.right,.imageblock[style*="float: right"]{margin:.25em 0 1.25em .625em}
|
|
.imageblock>.title{margin-bottom:0}
|
|
.imageblock.thumb,.imageblock.th{border-width:6px}
|
|
.imageblock.thumb>.title,.imageblock.th>.title{padding:0 .125em}
|
|
.image.left,.image.right{margin-top:.25em;margin-bottom:.25em;display:inline-block;line-height:0}
|
|
.image.left{margin-right:.625em}
|
|
.image.right{margin-left:.625em}
|
|
a.image{text-decoration:none;display:inline-block}
|
|
a.image object{pointer-events:none}
|
|
sup.footnote,sup.footnoteref{font-size:.875em;position:static;vertical-align:super}
|
|
sup.footnote a,sup.footnoteref a{text-decoration:none}
|
|
sup.footnote a:active,sup.footnoteref a:active{text-decoration:underline}
|
|
#footnotes{padding-top:.75em;padding-bottom:.75em;margin-bottom:.625em}
|
|
#footnotes hr{width:20%;min-width:6.25em;margin:-.25em 0 .75em 0;border-width:1px 0 0 0}
|
|
#footnotes .footnote{padding:0 .375em 0 .225em;line-height:1.3334;font-size:.875em;margin-left:1.2em;text-indent:-1.05em;margin-bottom:.2em}
|
|
#footnotes .footnote a:first-of-type{font-weight:bold;text-decoration:none}
|
|
#footnotes .footnote:last-of-type{margin-bottom:0}
|
|
#content #footnotes{margin-top:-.625em;margin-bottom:0;padding:.75em 0}
|
|
.gist .file-data>table{border:0;background:#fff;width:100%;margin-bottom:0}
|
|
.gist .file-data>table td.line-data{width:99%}
|
|
div.unbreakable{page-break-inside:avoid}
|
|
.big{font-size:larger}
|
|
.small{font-size:smaller}
|
|
.underline{text-decoration:underline}
|
|
.overline{text-decoration:overline}
|
|
.line-through{text-decoration:line-through}
|
|
.aqua{color:#00bfbf}
|
|
.aqua-background{background-color:#00fafa}
|
|
.black{color:#000}
|
|
.black-background{background-color:#000}
|
|
.blue{color:#0000bf}
|
|
.blue-background{background-color:#0000fa}
|
|
.fuchsia{color:#bf00bf}
|
|
.fuchsia-background{background-color:#fa00fa}
|
|
.gray{color:#606060}
|
|
.gray-background{background-color:#7d7d7d}
|
|
.green{color:#006000}
|
|
.green-background{background-color:#007d00}
|
|
.lime{color:#00bf00}
|
|
.lime-background{background-color:#00fa00}
|
|
.maroon{color:#600000}
|
|
.maroon-background{background-color:#7d0000}
|
|
.navy{color:#000060}
|
|
.navy-background{background-color:#00007d}
|
|
.olive{color:#606000}
|
|
.olive-background{background-color:#7d7d00}
|
|
.purple{color:#600060}
|
|
.purple-background{background-color:#7d007d}
|
|
.red{color:#bf0000}
|
|
.red-background{background-color:#fa0000}
|
|
.silver{color:#909090}
|
|
.silver-background{background-color:#bcbcbc}
|
|
.teal{color:#006060}
|
|
.teal-background{background-color:#007d7d}
|
|
.white{color:#bfbfbf}
|
|
.white-background{background-color:#fafafa}
|
|
.yellow{color:#bfbf00}
|
|
.yellow-background{background-color:#fafa00}
|
|
span.icon>.fa{cursor:default}
|
|
.admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default}
|
|
.admonitionblock td.icon .icon-note:before{content:"\f05a";color:#19407c}
|
|
.admonitionblock td.icon .icon-tip:before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111}
|
|
.admonitionblock td.icon .icon-warning:before{content:"\f071";color:#bf6900}
|
|
.admonitionblock td.icon .icon-caution:before{content:"\f06d";color:#bf3400}
|
|
.admonitionblock td.icon .icon-important:before{content:"\f06a";color:#bf0000}
|
|
.conum[data-value]{display:inline-block;color:#fff!important;background-color:rgba(0,0,0,.8);-webkit-border-radius:100px;border-radius:100px;text-align:center;font-size:.75em;width:1.67em;height:1.67em;line-height:1.67em;font-family:"Open Sans","DejaVu Sans",sans-serif;font-style:normal;font-weight:bold}
|
|
.conum[data-value] *{color:#fff!important}
|
|
.conum[data-value]+b{display:none}
|
|
.conum[data-value]:after{content:attr(data-value)}
|
|
pre .conum[data-value]{position:relative;top:-.125em}
|
|
b.conum *{color:inherit!important}
|
|
.conum:not([data-value]):empty{display:none}
|
|
dt,th.tableblock,td.content,div.footnote{text-rendering:optimizeLegibility}
|
|
h1,h2,p,td.content,span.alt{letter-spacing:-.01em}
|
|
p strong,td.content strong,div.footnote strong{letter-spacing:-.005em}
|
|
p,blockquote,dt,td.content,span.alt{font-size:1.0625rem}
|
|
p{margin-bottom:1.25rem}
|
|
.sidebarblock p,.sidebarblock dt,.sidebarblock td.content,p.tableblock{font-size:1em}
|
|
.exampleblock>.content{background-color:#fffef7;border-color:#e0e0dc;-webkit-box-shadow:0 1px 4px #e0e0dc;box-shadow:0 1px 4px #e0e0dc}
|
|
.print-only{display:none!important}
|
|
@media print{@page{margin:1.25cm .75cm}
|
|
*{-webkit-box-shadow:none!important;box-shadow:none!important;text-shadow:none!important}
|
|
a{color:inherit!important;text-decoration:underline!important}
|
|
a.bare,a[href^="#"],a[href^="mailto:"]{text-decoration:none!important}
|
|
a[href^="http:"]:not(.bare):after,a[href^="https:"]:not(.bare):after{content:"(" attr(href) ")";display:inline-block;font-size:.875em;padding-left:.25em}
|
|
abbr[title]:after{content:" (" attr(title) ")"}
|
|
pre,blockquote,tr,img,object,svg{page-break-inside:avoid}
|
|
thead{display:table-header-group}
|
|
svg{max-width:100%}
|
|
p,blockquote,dt,td.content{font-size:1em;orphans:3;widows:3}
|
|
h2,h3,#toctitle,.sidebarblock>.content>.title{page-break-after:avoid}
|
|
#toc,.sidebarblock,.exampleblock>.content{background:none!important}
|
|
#toc{border-bottom:1px solid #ddddd8!important;padding-bottom:0!important}
|
|
.sect1{padding-bottom:0!important}
|
|
.sect1+.sect1{border:0!important}
|
|
#header>h1:first-child{margin-top:1.25rem}
|
|
body.book #header{text-align:center}
|
|
body.book #header>h1:first-child{border:0!important;margin:2.5em 0 1em 0}
|
|
body.book #header .details{border:0!important;display:block;padding:0!important}
|
|
body.book #header .details span:first-child{margin-left:0!important}
|
|
body.book #header .details br{display:block}
|
|
body.book #header .details br+span:before{content:none!important}
|
|
body.book #toc{border:0!important;text-align:left!important;padding:0!important;margin:0!important}
|
|
body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-break-before:always}
|
|
.listingblock code[data-lang]:before{display:block}
|
|
#footer{background:none!important;padding:0 .9375em}
|
|
#footer-text{color:rgba(0,0,0,.6)!important;font-size:.9em}
|
|
.hide-on-print{display:none!important}
|
|
.print-only{display:block!important}
|
|
.hide-for-print{display:none!important}
|
|
.show-for-print{display:inherit!important}}
|
|
</style>
|
|
</head>
|
|
<body class="article toc2 toc-left">
|
|
<div id="header">
|
|
<h1>Spring Cloud Sleuth</h1>
|
|
<div id="toc" class="toc2">
|
|
<div id="toctitle">Table of Contents</div>
|
|
<ul class="sectlevel1">
|
|
<li><a href="#_spring_cloud_sleuth">Spring Cloud Sleuth</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#_terminology">Terminology</a></li>
|
|
<li><a href="#_purpose">Purpose</a></li>
|
|
<li><a href="#_adding_to_the_project">Adding to the project</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#_features">Features</a></li>
|
|
<li><a href="#_sampling">Sampling</a></li>
|
|
<li><a href="#_instrumentation">Instrumentation</a></li>
|
|
<li><a href="#_span_lifecycle">Span lifecycle</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#creating-and-closing-spans">Creating and closing spans</a></li>
|
|
<li><a href="#continuing-spans">Continuing spans</a></li>
|
|
<li><a href="#creating-spans-with-explicit-parent">Creating spans with an explicit parent</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#_naming_spans">Naming spans</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#__spanname_annotation">@SpanName annotation</a></li>
|
|
<li><a href="#_tostring_method">toString() method</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#_span_data_as_messages">Span Data as Messages</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#_zipkin_consumer">Zipkin Consumer</a></li>
|
|
<li><a href="#_custom_consumer">Custom Consumer</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="#_metrics">Metrics</a></li>
|
|
<li><a href="#_integrations">Integrations</a>
|
|
<ul class="sectlevel2">
|
|
<li><a href="#_runnable_and_callable">Runnable and Callable</a></li>
|
|
<li><a href="#_hystrix">Hystrix</a></li>
|
|
<li><a href="#_http_integration">HTTP integration</a></li>
|
|
<li><a href="#_http_client_integration">HTTP client integration</a></li>
|
|
<li><a href="#_feign">Feign</a></li>
|
|
<li><a href="#_asynchronous_communication">Asynchronous communication</a></li>
|
|
<li><a href="#_messaging">Messaging</a></li>
|
|
<li><a href="#_zuul">Zuul</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div id="content">
|
|
<div class="sect1">
|
|
<h2 id="_spring_cloud_sleuth">Spring Cloud Sleuth</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Spring Cloud Sleuth implements a distributed tracing solution for <a href="http://cloud.spring.io">Spring Cloud</a>.</p>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_terminology">Terminology</h3>
|
|
<div class="paragraph">
|
|
<p>Spring Cloud Sleuth borrows <a href="http://research.google.com/pubs/pub36356.html">Dapper’s</a> terminology.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p><strong>Span:</strong> The basic unit of work. For example, sending an RPC is a new span, as is sending a response to an
|
|
RPC. Span’s are identified by a unique 64-bit ID for the span and another 64-bit ID for the trace the span
|
|
is a part of. Spans also have other data, such as descriptions, timestamped events, key-value
|
|
annotations (tags), the ID of the span that caused them, and process ID’s (normally IP address).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Spans are started and stopped, and they keep track of their timing information. Once you create a
|
|
span, you must stop it at some point in the future.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p><strong>Trace:</strong> A set of spans forming a tree-like structure. For example, if you are running a distributed
|
|
big-data store, a trace might be formed by a put request.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p><strong>Annotation:</strong> is used to record existence of an event in time. Some of the core annotations used to define
|
|
the start and stop of a request are:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><strong>cs</strong> - Client Sent - The client has made a request. This annotation depicts the start of the span.</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>sr</strong> - Server Received - The server side got the request and will start processing it.
|
|
If one subtracts the cs timestamp from this timestamp one will receive the network latency.</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>ss</strong> - Server Sent - Annotated upon completion of request processing (when the response
|
|
got sent back to the client). If one subtracts the sr timestamp from this timestamp one
|
|
will receive the time needed by the server side to process the request.</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>cr</strong> - Client Received - Signifies the end of the span. The client has successfully received the
|
|
response from the server side. If one subtracts the cs timestamp from this timestamp one
|
|
will receive the whole time needed by the client to receive the response from the server.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Visualization of what <strong>Span</strong> and <strong>Trace</strong> will look in a system together with the Zipkin annotations:</p>
|
|
</div>
|
|
<div class="imageblock">
|
|
<div class="content">
|
|
<img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-sleuth/master/docs/src/main/asciidoc/images/trace-id.png" alt="Trace Info propagation">
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Each color of a note signifies a span (7 spans - from <strong>A</strong> to <strong>G</strong>). If you have such information in the note:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>Trace Id = X
|
|
Span Id = D
|
|
Client Sent</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>That means that the current span has <strong>Trace-Id</strong> set to <strong>X</strong>, <strong>Span-Id</strong> set to <strong>D</strong>. It also has emitted
|
|
<strong>Client Sent</strong> event.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>This is how the visualization of the parent / child relationship of spans would look like:</p>
|
|
</div>
|
|
<div class="imageblock">
|
|
<div class="content">
|
|
<img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-sleuth/master/docs/src/main/asciidoc/images/parents.png" alt="Parent child relationship">
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_purpose">Purpose</h3>
|
|
<div class="paragraph">
|
|
<p>In the following sections the example from the image above will be taken into consideration.</p>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_distributed_tracing_with_zipkin">Distributed tracing with Zipkin</h4>
|
|
<div class="paragraph">
|
|
<p>Altogether there are <strong>10 spans</strong> . If you go to traces in Zipkin you will see this number:</p>
|
|
</div>
|
|
<div class="imageblock">
|
|
<div class="content">
|
|
<img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-sleuth/master/docs/src/main/asciidoc/images/zipkin-traces.png" alt="Traces">
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>However if you pick a particular trace then you will see <strong>7 spans</strong>:</p>
|
|
</div>
|
|
<div class="imageblock">
|
|
<div class="content">
|
|
<img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-sleuth/master/docs/src/main/asciidoc/images/zipkin-ui.png" alt="Traces Info propagation">
|
|
</div>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
When picking a particular trace you will see merged spans. That means that if there were 2 spans sent to
|
|
Zipkin with Server Received and Server Sent / Client Received and Client Sent
|
|
annotations then they will presented as a single span.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In the image depicting the visualization of what <strong>Span</strong> and <strong>Trace</strong> is you can see 20
|
|
colorful labels. How does it happen that in Zipkin 10 spans are received?</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>2 span <strong>A</strong> labels signify span started and closed. Upon closing a single span is sent to Zipkin.</p>
|
|
</li>
|
|
<li>
|
|
<p>4 span <strong>B</strong> labels are in fact are single span with 4 annotations. However this span is composed of
|
|
two separate instances. One sent from service 1 and one from service 2. So in fact two span instances will be sent
|
|
to Zipkin and merged there.</p>
|
|
</li>
|
|
<li>
|
|
<p>2 span <strong>C</strong> labels signify span started and closed. Upon closing a single span is sent to Zipkin.</p>
|
|
</li>
|
|
<li>
|
|
<p>4 span <strong>B</strong> labels are in fact are single span with 4 annotations. However this span is composed of
|
|
two separate instances. One sent from service 2 and one from service 3. So in fact two span instances will be sent
|
|
to Zipkin and merged there.</p>
|
|
</li>
|
|
<li>
|
|
<p>2 span <strong>E</strong> labels signify span started and closed. Upon closing a single span is sent to Zipkin.</p>
|
|
</li>
|
|
<li>
|
|
<p>4 span <strong>B</strong> labels are in fact are single span with 4 annotations. However this span is composed of
|
|
two separate instances. One sent from service 2 and one from service 4. So in fact two span instances will be sent
|
|
to Zipkin and merged there.</p>
|
|
</li>
|
|
<li>
|
|
<p>2 span <strong>G</strong> labels signify span started and closed. Upon closing a single span is sent to Zipkin.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>So 1 span from <strong>A</strong>, 2 spans from <strong>B</strong>, 1 span from <strong>C</strong>, 2 spans from <strong>D</strong>, 1 span from <strong>E</strong>, 2 spans from <strong>F</strong> and 1 from <strong>G</strong>.
|
|
Altogether <strong>10</strong> spans.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_log_correlation">Log correlation</h4>
|
|
<div class="paragraph">
|
|
<p>When grepping the logs of those four applications by trace id equal to e.g. <code>2485ec27856c56f4</code> one would get the following:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>service1.log:2016-02-26 11:15:47.561 INFO [service1,2485ec27856c56f4,2485ec27856c56f4,true] 68058 --- [nio-8081-exec-1] i.s.c.sleuth.docs.service1.Application : Hello from service1. Calling service2
|
|
service2.log:2016-02-26 11:15:47.710 INFO [service2,2485ec27856c56f4,9aa10ee6fbde75fa,true] 68059 --- [nio-8082-exec-1] i.s.c.sleuth.docs.service2.Application : Hello from service2. Calling service3 and then service4
|
|
service3.log:2016-02-26 11:15:47.895 INFO [service3,2485ec27856c56f4,1210be13194bfe5,true] 68060 --- [nio-8083-exec-1] i.s.c.sleuth.docs.service3.Application : Hello from service3
|
|
service2.log:2016-02-26 11:15:47.924 INFO [service2,2485ec27856c56f4,9aa10ee6fbde75fa,true] 68059 --- [nio-8082-exec-1] i.s.c.sleuth.docs.service2.Application : Got response from service3 [Hello from service3]
|
|
service4.log:2016-02-26 11:15:48.134 INFO [service4,2485ec27856c56f4,1b1845262ffba49d,true] 68061 --- [nio-8084-exec-1] i.s.c.sleuth.docs.service4.Application : Hello from service4
|
|
service2.log:2016-02-26 11:15:48.156 INFO [service2,2485ec27856c56f4,9aa10ee6fbde75fa,true] 68059 --- [nio-8082-exec-1] i.s.c.sleuth.docs.service2.Application : Got response from service4 [Hello from service4]
|
|
service1.log:2016-02-26 11:15:48.182 INFO [service1,2485ec27856c56f4,2485ec27856c56f4,true] 68058 --- [nio-8081-exec-1] i.s.c.sleuth.docs.service1.Application : Got response from service2 [Hello from service2, response from service3 [Hello from service3] and from service4 [Hello from service4]]</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If you’re using a log aggregating tool like <a href="https://www.elastic.co/products/kibana">Kibana</a>,
|
|
<a href="http://www.splunk.com/">Splunk</a> etc. you can order the events that took place. An example of
|
|
Kibana would look like this:</p>
|
|
</div>
|
|
<div class="imageblock">
|
|
<div class="content">
|
|
<img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-sleuth/master/docs/src/main/asciidoc/images/kibana.png" alt="Log correlation with Kibana">
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If you want to use <a href="https://www.elastic.co/guide/en/logstash/current/index.html">Logstash</a> here is the Grok pattern for Logstash:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>filter {
|
|
# pattern matching logback pattern
|
|
grok {
|
|
match => { "message" => "%{TIMESTAMP_ISO8601:timestamp}\s+%{LOGLEVEL:severity}\s+\[%{DATA:service},%{DATA:trace},%{DATA:span},%{DATA:exportable}\]\s+%{DATA:pid}---\s+\[%{DATA:thread}\]\s+%{DATA:class}\s+:\s+%{GREEDYDATA:rest}" }
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
If you want to use Grok together with the logs from Cloud Foundry you have to use this pattern:
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code>filter {
|
|
# pattern matching logback pattern
|
|
grok {
|
|
match => { "message" => "(?m)OUT\s+%{TIMESTAMP_ISO8601:timestamp}\s+%{LOGLEVEL:severity}\s+\[%{DATA:service},%{DATA:trace},%{DATA:span},%{DATA:exportable}\]\s+%{DATA:pid}---\s+\[%{DATA:thread}\]\s+%{DATA:class}\s+:\s+%{GREEDYDATA:rest}" }
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_adding_to_the_project">Adding to the project</h3>
|
|
<div class="paragraph">
|
|
<p>In general if you want to profit only from Spring Cloud Sleuth without the Zipkin integration just add
|
|
the <strong>spring-cloud-starter-sleuth</strong> module to your project.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If you want both Sleuth and Zipkin just add the <strong>spring-cloud-starter-zipkin</strong> dependency.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_features">Features</h2>
|
|
<div class="sectionbody">
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>Adds trace and span ids to the Slf4J MDC, so you can extract all the logs from a given trace or span in a log aggregator. Example logs:</p>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre>2016-02-02 15:30:57.902 INFO [bar,6bfd228dc00d216b,6bfd228dc00d216b,false] 23030 --- [nio-8081-exec-3] ...
|
|
2016-02-02 15:30:58.372 ERROR [bar,6bfd228dc00d216b,6bfd228dc00d216b,false] 23030 --- [nio-8081-exec-3] ...
|
|
2016-02-02 15:31:01.936 INFO [bar,46ab0d418373cbc9,46ab0d418373cbc9,false] 23030 --- [nio-8081-exec-4] ...</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>notice the <code>[appname,traceId,spanId,exportable]</code> entries from the MDC:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><strong>spanId</strong> - the id of a specific operation that took place</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>appname</strong> - the name of the application that logged the span</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>traceId</strong> - the id of the latency graph that contains the span</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>exportable</strong> - whether the log should be exported to Zipkin or not</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</li>
|
|
<li>
|
|
<p>Provides an abstraction over common distributed tracing data models: traces, spans (forming a DAG), annotations,
|
|
key-value annotations. Loosely based on HTrace, but Zipkin (Dapper) compatible.</p>
|
|
</li>
|
|
<li>
|
|
<p>Sleuth records timing information to aid in latency analysis. Using sleuth, you can pinpoint causes of
|
|
latency in your applications. Sleuth is written to not log too much, and to not cause your production application to crash.</p>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>propagates structural data about your call-graph in-band, and the rest out-of-band.</p>
|
|
</li>
|
|
<li>
|
|
<p>includes opinionated instrumentation of layers such as HTTP</p>
|
|
</li>
|
|
<li>
|
|
<p>includes sampling policy to manage volume</p>
|
|
</li>
|
|
<li>
|
|
<p>can report to a Zipkin system for query and visualization</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</li>
|
|
<li>
|
|
<p>Instruments common ingress and egress points from Spring applications (servlet filter, async endpoints,
|
|
rest template, scheduled actions, message channels, zuul filters, feign client).</p>
|
|
</li>
|
|
<li>
|
|
<p>Provides simple metrics of accepted / dropped spans.</p>
|
|
</li>
|
|
<li>
|
|
<p>If <code>spring-cloud-sleuth-zipkin</code> then the app will generate and collect Zipkin-compatible traces.
|
|
By default it sends them via HTTP to a Zipkin server on localhost (port 9411).
|
|
Configure the location of the service using <code>spring.zipkin.baseUrl</code>.</p>
|
|
</li>
|
|
<li>
|
|
<p>If <code>spring-cloud-sleuth-stream</code> then the app will generate and collect traces via <a href="https://github.com/spring-cloud/spring-cloud-stream">Spring Cloud Stream</a>.
|
|
Your app automatically becomes a producer of tracer messages that are sent over your broker of choice
|
|
(e.g. RabbitMQ, Apache Kafka, Redis).</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="admonitionblock important">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Important</div>
|
|
</td>
|
|
<td class="content">
|
|
If using Zipkin or Stream, configure the percentage of spans exported using <code>spring.sleuth.sampler.percentage</code>
|
|
(default 0.1, i.e. 10%). <strong>Otherwise you might think that Sleuth is not working cause it’s omitting some spans.</strong>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
the SLF4J MDC is always set and logback users will immediately see the trace and span ids in logs per the example
|
|
above. Other logging systems have to configure their own formatter to get the same result. The default is
|
|
<code>logging.pattern.level</code> set to <code>%clr(%5p) %clr([${spring.application.name:},%X{X-Trace-Id:-},%X{X-Span-Id:-},%X{X-Span-Export:-}]){yellow}</code>
|
|
(this is a Spring Boot feature for logback users).
|
|
<strong>This means that if you’re not using SLF4J this pattern WILL NOT be automatically applied</strong>.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_sampling">Sampling</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>In distributed tracing the data volumes can be very high so sampling
|
|
can be important (you usually don’t need to export all spans to get a
|
|
good picture of what is happening). Spring Cloud Sleuth has a
|
|
<code>Sampler</code> strategy that you can implement to take control of the
|
|
sampling algorithm. Samplers do not stop span (correlation) ids from
|
|
being generated, but they do prevent the tags and events being
|
|
attached and exported. By default you get a strategy that continues to
|
|
trace if a span is already active, but new ones are always marked as
|
|
non-exportable. If all your apps run with this sampler you will see
|
|
traces in logs, but not in any remote store. For testing the default
|
|
is often enough, and it probably is all you need if you are only using
|
|
the logs (e.g. with an ELK aggregator). If you are exporting span data
|
|
to Zipkin or Spring Cloud Stream, there is also an <code>AlwaysSampler</code>
|
|
that exports everything and a <code>PercentageBasedSampler</code> that samples a
|
|
fixed fraction of spans.</p>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
the <code>PercentageBasedSampler</code> is the default if you are using
|
|
<code>spring-cloud-sleuth-zipkin</code> or <code>spring-cloud-sleuth-stream</code>. You can
|
|
configure the exports using <code>spring.sleuth.sampler.percentage</code>.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A sampler can be installed just by creating a bean definition, e.g:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">@Bean
|
|
public Sampler defaultSampler() {
|
|
return new AlwaysSampler();
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_instrumentation">Instrumentation</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Spring Cloud Sleuth instruments all your Spring application
|
|
automatically, so you shouldn’t have to do anything to activate
|
|
it. The instrumentation is added using a variety of technologies
|
|
according to the stack that is available, e.g. for a servlet web
|
|
application we use a <code>Filter</code>, and for Spring Integration we use
|
|
<code>ChannelInterceptors</code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>You can customize the keys used in span tags. To limit the volume of
|
|
span data, by default an HTTP request will be tagged only with a
|
|
handful of metadata like the status code, host and URL. You can add
|
|
request headers by configuring <code>spring.sleuth.keys.http.headers</code> (a
|
|
list of header names).</p>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
Remember that tags are only collected and exported if there is a
|
|
<code>Sampler</code> that allows it (by default there is not, so there is no
|
|
danger of accidentally collecting too much data without configuring
|
|
something).
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
Currently the instrumentation in Spring Cloud Sleuth is eager - it means that
|
|
we’re actively trying to pass the tracing context between threads. Also timing events
|
|
are captured even when sleuth isn’t exporting data to a tracing system.
|
|
This approach may change in the future towards being lazy on this matter.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_span_lifecycle">Span lifecycle</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>You can do the following operations on the Span by means of <strong>Tracer</strong> interface:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><a href="#creating-and-closing-spans">start</a> - when you start a span its name is assigned and start timestamp is recorded.</p>
|
|
</li>
|
|
<li>
|
|
<p><a href="#creating-and-closing-spans">close</a> - the span gets finished (the end time of the span is recorded) and if
|
|
the span is <strong>exportable</strong> then it will be eligible for collection to Zipkin.
|
|
The span is also removed from the current thread.</p>
|
|
</li>
|
|
<li>
|
|
<p><a href="#continuing-spans">continue</a> - a new instance of span will be created whereas it will be a copy of the
|
|
one that it continues.</p>
|
|
</li>
|
|
<li>
|
|
<p><a href="#continuing-spans">detach</a> - the span doesn’t get stopped or closed. It only gets removed from the current thread.</p>
|
|
</li>
|
|
<li>
|
|
<p><a href="#creating-spans-with-explicit-parent">create with explicit parent</a> - you can create a new span and set an explicit parent to it</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="creating-and-closing-spans">Creating and closing spans</h3>
|
|
<div class="paragraph">
|
|
<p>You can manually create spans by using the <strong>Tracer</strong> interface.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">// Start a span. If there was a span present in this thread it will become
|
|
// the `newSpan`'s parent.
|
|
Span newSpan = this.tracer.createSpan("calculateTax");
|
|
try {
|
|
// ...
|
|
// You can tag a span
|
|
this.tracer.addTag("taxValue", taxValue);
|
|
// ...
|
|
// You can log an event on a span
|
|
newSpan.logEvent("taxCalculated");
|
|
} finally {
|
|
// Once done remember to close the span. This will allow collecting
|
|
// the span to send it to Zipkin
|
|
this.tracer.close(newSpan);
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In this example we could see how to create a new instance of span. Assuming that there already
|
|
was a span present in this thread then it would become the parent of that span.</p>
|
|
</div>
|
|
<div class="admonitionblock important">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Important</div>
|
|
</td>
|
|
<td class="content">
|
|
Always clean after you create a span! Don’t forget to close a span if you want to send it to Zipkin.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="continuing-spans">Continuing spans</h3>
|
|
<div class="paragraph">
|
|
<p>Sometimes you don’t want to create a new span but you want to continue one. Example of such a
|
|
situation might be (of course it all depends on the use-case):</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><strong>AOP</strong> - If there was already a span created before an aspect was reached then you might not want to create a new span.</p>
|
|
</li>
|
|
<li>
|
|
<p><strong>Hystrix</strong> - executing a Hystrix command is most likely a logical part of the current processing. It’s in fact
|
|
only a technical implementation detail that you wouldn’t necessarily want to reflect in tracing as a separate being.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The continued instance of span is equal to the one that it continues:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">Span continuedSpan = this.tracer.continueSpan(spanToContinue);
|
|
assertThat(continuedSpan).isEqualTo(spanToContinue);</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>To continue a span you can use the <strong>Tracer</strong> interface.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">// let's assume that we're in a thread Y and we've received
|
|
// the `initialSpan` from thread X
|
|
Span continuedSpan = this.tracer.continueSpan(initialSpan);
|
|
try {
|
|
// ...
|
|
// You can tag a span
|
|
this.tracer.addTag("taxValue", taxValue);
|
|
// ...
|
|
// You can log an event on a span
|
|
continuedSpan.logEvent("taxCalculated");
|
|
} finally {
|
|
// Once done remember to detach the span. That way you'll
|
|
// safely remove it from the current thread without closing it
|
|
this.tracer.detach(continuedSpan);
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="admonitionblock important">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Important</div>
|
|
</td>
|
|
<td class="content">
|
|
Always clean after you create a span! Don’t forget to detach a span if some work was done started in one
|
|
thread (e.g. thread X) and it’s waiting for other threads (e.g. Y, Z) to finish.
|
|
Then the spans in the threads Y, Z should be detached at the end of their work. When the results are collected
|
|
the span in thread X should be closed.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="creating-spans-with-explicit-parent">Creating spans with an explicit parent</h3>
|
|
<div class="paragraph">
|
|
<p>There is a possibility that you want to start a new span and provide an explicit parent of that span.
|
|
Let’s assume that the parent of a span is in one thread and you want to start a new span in another thread. The
|
|
<code>startSpan</code> method of the <code>Tracer</code> interface is the method you are looking for.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">// let's assume that we're in a thread Y and we've received
|
|
// the `initialSpan` from thread X. `initialSpan` will be the parent
|
|
// of the `newSpan`
|
|
Span newSpan = this.tracer.createSpan("calculateCommission", initialSpan);
|
|
try {
|
|
// ...
|
|
// You can tag a span
|
|
this.tracer.addTag("commissionValue", commissionValue);
|
|
// ...
|
|
// You can log an event on a span
|
|
newSpan.logEvent("commissionCalculated");
|
|
} finally {
|
|
// Once done remember to close the span. This will allow collecting
|
|
// the span to send it to Zipkin. The tags and events set on the
|
|
// newSpan will not be present on the parent
|
|
this.tracer.close(newSpan);
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="admonitionblock important">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Important</div>
|
|
</td>
|
|
<td class="content">
|
|
After having created such a span remember to close it. Otherwise you will see a lot of warnings in your logs
|
|
related to the fact that you have a span present in the current thread other than the one you’re trying to close.
|
|
What’s worse your spans won’t get closed properly thus will not get collected to Zipkin.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_naming_spans">Naming spans</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Picking a span name is not a trivial task. Span name should depict an operation name. The name should
|
|
be low cardinality (e.g. not include identifiers).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Since there is a lot of instrumentation going on some of the span names will be
|
|
artificial like:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><code>http:path</code> when received an http request on a given path</p>
|
|
</li>
|
|
<li>
|
|
<p><code>async</code> for asynchronous operations done via wrapped <code>Callable</code> and <code>Runnable</code>.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>@Scheduled</code> annotated methods will return the simple name of the class.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Fortunately, for the asynchronous processing you can provide explicit naming.</p>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="__spanname_annotation">@SpanName annotation</h3>
|
|
<div class="paragraph">
|
|
<p>You can do name the span explicitly via the <code>@SpanName</code> annotation.</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">@SpanName("calculateTax")
|
|
class TaxCountingRunnable implements Runnable {
|
|
|
|
@Override public void run() {
|
|
// perform logic
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In this case, when processed in the following manner:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">Runnable runnable = new TraceRunnable(tracer, spanNamer, new TaxCountingRunnable());
|
|
Future<?> future = executorService.submit(runnable);
|
|
// ... some additional logic ...
|
|
future.get();</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The span will be named <code>calculateTax</code>.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_tostring_method">toString() method</h3>
|
|
<div class="paragraph">
|
|
<p>It’s pretty rare to create separate classes for <code>Runnable</code> or <code>Callable</code>. Typically one creates an anonymous
|
|
instance of those classes. You can’t annotate such classes thus to override that, if there is no <code>@SpanName</code> annotation present,
|
|
we’re checking if the class has a custom implementation of the <code>toString()</code> method.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>So executing such code:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">Runnable runnable = new TraceRunnable(tracer, spanNamer, new Runnable() {
|
|
@Override public void run() {
|
|
// perform logic
|
|
}
|
|
|
|
@Override public String toString() {
|
|
return "calculateTax";
|
|
}
|
|
});
|
|
Future<?> future = executorService.submit(runnable);
|
|
// ... some additional logic ...
|
|
future.get();</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>will lead in creating a span named <code>calculateTax</code>.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_span_data_as_messages">Span Data as Messages</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>You can accumulate and send span data over
|
|
<a href="http://cloud.spring.io/spring-cloud-stream">Spring Cloud Stream</a> by
|
|
including the <code>spring-cloud-sleuth-stream</code> jar as a dependency, and
|
|
adding a Channel Binder implementation
|
|
(e.g. <code>spring-cloud-starter-stream-rabbit</code> for RabbitMQ or
|
|
<code>spring-cloud-starter-stream-kafka</code> for Kafka). This will
|
|
automatically turn your app into a producer of messages with payload
|
|
type <code>Spans</code>.</p>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_zipkin_consumer">Zipkin Consumer</h3>
|
|
<div class="paragraph">
|
|
<p>There is a special convenience annotation for setting up a message consumer
|
|
for the Span data and pushing it into a Zipkin <code>SpanStore</code>. This application</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">@SpringBootApplication
|
|
@EnableZipkinStreamServer
|
|
public class Consumer {
|
|
public static void main(String[] args) {
|
|
SpringApplication.run(Consumer.class, args);
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>will listen for the Span data on whatever transport you provide via a
|
|
Spring Cloud Stream <code>Binder</code> (e.g. include
|
|
<code>spring-cloud-starter-stream-rabbit</code> for RabbitMQ, and similar
|
|
starters exist for Redis and Kafka). The app will also be a
|
|
<a href="https://github.com/openzipkin/zipkin-java">Zipkin query server</a>, so you
|
|
can point a standard Zipkin UI at it (e.g. run the consumer app on
|
|
port 9411 if you want the query server on the same host and the
|
|
default configuration).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The default <code>SpanStore</code> is in-memory (good for demos and getting
|
|
started quickly). For a more robust solution you can add MySQL and
|
|
<code>spring-boot-starter-jdbc</code> to your classpath and enable the JDBC
|
|
<code>SpanStore</code> via configuration, e.g.:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-yaml" data-lang="yaml">spring:
|
|
rabbitmq:
|
|
host: ${RABBIT_HOST:localhost}
|
|
datasource:
|
|
schema: classpath:/mysql.sql
|
|
url: jdbc:mysql://${MYSQL_HOST:localhost}/test
|
|
username: root
|
|
password: root
|
|
# Switch this on to create the schema on startup:
|
|
initialize: true
|
|
continueOnError: true
|
|
sleuth:
|
|
enabled: false
|
|
zipkin:
|
|
store:
|
|
type: mysql</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
The <code>@EnableZipkinStreamServer</code> is also annotated with
|
|
<code>@EnableZipkinServer</code> so the process will also expose the standard
|
|
Zipkin server endpoints for collecting spans over HTTP, and for
|
|
querying in the Zipkin Web UI.
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_custom_consumer">Custom Consumer</h3>
|
|
<div class="paragraph">
|
|
<p>A custom consumer can also easily be implemented using
|
|
<code>spring-cloud-sleuth-stream</code> and binding to the <code>SleuthSink</code>. Example:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">@EnableBinding(SleuthSink.class)
|
|
@SpringBootApplication(exclude = SleuthStreamAutoConfiguration.class)
|
|
@MessageEndpoint
|
|
public class Consumer {
|
|
|
|
@ServiceActivator(inputChannel = SleuthSink.INPUT)
|
|
public void sink(Spans input) throws Exception {
|
|
// ... process spans
|
|
}
|
|
}</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="admonitionblock note">
|
|
<table>
|
|
<tr>
|
|
<td class="icon">
|
|
<div class="title">Note</div>
|
|
</td>
|
|
<td class="content">
|
|
the sample consumer application above explicitly excludes
|
|
<code>SleuthStreamAutoConfiguration</code> so it doesn’t send messages to itself,
|
|
but this is optional (you might actually want to trace requests into
|
|
the consumer app).
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_metrics">Metrics</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Currently Spring Cloud Sleuth registers very simple metrics related to spans.
|
|
It’s using the <a href="http://docs.spring.io/spring-boot/docs/current/reference/html/production-ready-metrics.html#production-ready-recording-metrics">Spring Boot’s metrics support</a>
|
|
to calculate the number of accepted and dropped spans. Each time a span gets
|
|
sent to Zipkin the number of accepted spans will increase. If there’s an error then
|
|
the number of dropped spans will get increased.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_integrations">Integrations</h2>
|
|
<div class="sectionbody">
|
|
<div class="sect2">
|
|
<h3 id="_runnable_and_callable">Runnable and Callable</h3>
|
|
<div class="paragraph">
|
|
<p>If you’re wrapping your logic in <code>Runnable</code> or <code>Callable</code> it’s enough to wrap those classes in their Sleuth representative.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Example for <code>Runnable</code>:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">Runnable runnable = new Runnable() {
|
|
@Override
|
|
public void run() {
|
|
// do some work
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "spanNameFromToStringMethod";
|
|
}
|
|
};
|
|
// Manual `TraceRunnable` creation with explicit "calculateTax" Span name
|
|
Runnable traceRunnable = new TraceRunnable(tracer, spanNamer, runnable, "calculateTax");
|
|
// Wrapping `Runnable` with `Tracer`. The Span name will be taken either from the
|
|
// `@SpanName` annotation or from `toString` method
|
|
Runnable traceRunnableFromTracer = tracer.wrap(runnable);</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Example for <code>Callable</code>:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">Callable<String> callable = new Callable<String>() {
|
|
@Override
|
|
public String call() throws Exception {
|
|
return someLogic();
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "spanNameFromToStringMethod";
|
|
}
|
|
};
|
|
// Manual `TraceCallable` creation with explicit "calculateTax" Span name
|
|
Callable<String> traceCallable = new TraceCallable<>(tracer, spanNamer, callable, "calculateTax");
|
|
// Wrapping `Callable` with `Tracer`. The Span name will be taken either from the
|
|
// `@SpanName` annotation or from `toString` method
|
|
Callable<String> traceCallableFromTracer = tracer.wrap(callable);</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>That way you will ensure that a new Span is created and closed for each execution.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_hystrix">Hystrix</h3>
|
|
<div class="sect3">
|
|
<h4 id="_custom_concurrency_strategy">Custom Concurrency Strategy</h4>
|
|
<div class="paragraph">
|
|
<p>We’re registering a custom <a href="https://github.com/Netflix/Hystrix/wiki/Plugins#concurrencystrategy"><code>HystrixConcurrencyStrategy</code></a>
|
|
that wraps all <code>Callable</code> instances into their Sleuth representative -
|
|
the <code>TraceCallable</code>. The strategy either starts or continues a span depending on the fact whether tracing was already going
|
|
on before the Hystrix command was called. To disable the custom Hystrix Concurrency Strategy set the <code>spring.sleuth.hystrix.strategy.enabled</code> to <code>false</code>.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_manual_command_setting">Manual Command setting</h4>
|
|
<div class="paragraph">
|
|
<p>Assuming that you have the following <code>HystrixCommand</code>:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">HystrixCommand<String> hystrixCommand = new HystrixCommand<String>(setter) {
|
|
@Override
|
|
protected String run() throws Exception {
|
|
return someLogic();
|
|
}
|
|
};</code></pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In order to pass the tracing information you have to wrap the same logic in the Sleuth version of the <code>HystrixCommand</code> which is the
|
|
<code>TraceCommand</code>:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre class="highlight"><code class="language-java" data-lang="java">TraceCommand<String> traceCommand = new TraceCommand<String>(tracer, traceKeys, setter) {
|
|
@Override
|
|
public String doRun() throws Exception {
|
|
return someLogic();
|
|
}
|
|
};</code></pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_http_integration">HTTP integration</h3>
|
|
<div class="paragraph">
|
|
<p>Features from this section can be disabled by providing the <code>spring.sleuth.web.enabled</code> property with value equal to <code>false</code>.</p>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_http_filter">HTTP Filter</h4>
|
|
<div class="paragraph">
|
|
<p>Via the <code>TraceFilter</code> all sampled incoming requests result in creation of a Span. That Span’s name is <code>http:</code> + the path to which
|
|
the request was sent. E.g. if the request was sent to <code>/foo/bar</code> then the name will be <code>http:/foo/bar</code>. You can configure which URIs you would
|
|
like to skip via the <code>spring.sleuth.instrument.web.skipPattern</code> property. If you have <code>ManagementServerProperties</code> on classpath then
|
|
its value of <code>contextPath</code> gets appended to the provided skip pattern.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_async_servlet_support">Async Servlet support</h4>
|
|
<div class="paragraph">
|
|
<p>If your controller returns a <code>Callable</code> or a <code>WebAsyncTask</code> Spring Cloud Sleuth will continue the existing span instead of creating a new one.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_http_client_integration">HTTP client integration</h3>
|
|
<div class="sect3">
|
|
<h4 id="_synchronous_rest_template">Synchronous Rest Template</h4>
|
|
<div class="paragraph">
|
|
<p>We’re injecting a <code>RestTemplate</code> interceptor that ensures that all the tracing information is passed to the requests. Each time a
|
|
call is made a new Span is created. It gets closed upon receiving the response. In order to block the synchronous <code>RestTemplate</code> features
|
|
just set <code>spring.sleuth.client.enabled</code> to <code>false</code>.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_asynchronous_rest_template">Asynchronous Rest Template</h4>
|
|
<div class="paragraph">
|
|
<p>Custom instrumentation is set to create and close Spans upon sending and receiving requests. To block the <code>AsyncRestTemplate</code>
|
|
features set <code>spring.sleuth.async.client.enabled</code> to <code>false</code>.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_feign">Feign</h3>
|
|
<div class="paragraph">
|
|
<p>By default Spring Cloud Sleuth provides integration with feign via the <code>TraceFeignClientAutoConfiguration</code>. You can disable it entirely
|
|
by setting <code>spring.sleuth.feign.enabled</code> to false. If you do so then no Feign related instrumentation will take place.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Part of Feign instrumentation is done via a <code>FeignBeanPostProcessor</code>. You can disable it by providing the <code>spring.sleuth.feign.processor.enabled</code> equal to <code>false</code>.
|
|
If you set it like this then Spring Cloud Sleuth will not instrument any of your custom Feign components. All the default instrumentation
|
|
however will be still there.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_asynchronous_communication">Asynchronous communication</h3>
|
|
<div class="paragraph">
|
|
<p>In Spring Cloud Sleuth we’re instrumenting async related components so that the tracing information is passed between threads. You can disable this behaviour
|
|
by setting the value of <code>spring.sleuth.async.enabled</code> to <code>false</code>.</p>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="__async_scheduled_annotated_methods">@Async / @Scheduled annotated methods</h4>
|
|
<div class="paragraph">
|
|
<p>If you annotate your method with <code>@Async</code> / <code>@Scheduled</code> then we’ll automatically create a new Span with the following characteristics:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>the Span name will be the annotated method name</p>
|
|
</li>
|
|
<li>
|
|
<p>the Span will be tagged with that method’s class name and the method name too</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_executor_executorservice_and_scheduledexecutorservice">Executor, ExecutorService and ScheduledExecutorService</h4>
|
|
<div class="paragraph">
|
|
<p>We’re providing <code>LazyTraceExecutor</code>, <code>TraceableExecutorService</code> and <code>TraceableScheduledExecutorService</code>. Those implementations
|
|
are creating Spans each time a new task is submitted, invoked or scheduled.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_messaging">Messaging</h3>
|
|
<div class="paragraph">
|
|
<p>Spring Cloud Sleuth integrates with <a href="http://projects.spring.io/spring-integration/">Spring Integration</a>. It creates spans for publish and
|
|
subscribe events. To disable Spring Integration instrumentation, set <code>spring.sleuth.integration.enabled</code> to false.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_zuul">Zuul</h3>
|
|
<div class="paragraph">
|
|
<p>We’re registering Zuul filters to propagate the tracing information (the request header is enriched with tracing data).
|
|
To disable Zuul support set the <code>spring.sleuth.zuul.enabled</code> property to <code>false</code>.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div id="footer">
|
|
<div id="footer-text">
|
|
Last updated 2016-03-09 18:58:32 CET
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html> |