:first-child{margin-top:0!important}.markdown-body>:last-child{margin-bottom:0!important}.markdown-body a:not([href]){color:inherit;text-decoration:none}.markdown-body .anchor{float:left;padding-right:4px;margin-left:-20px;line-height:1}.markdown-body .anchor:focus{outline:0}.markdown-body blockquote,.markdown-body dl,.markdown-body ol,.markdown-body p,.markdown-body pre,.markdown-body table,.markdown-body ul{margin-top:0;margin-bottom:16px}.markdown-body hr{overflow:hidden;background:#e1e4e8;height:.25em;padding:0;margin:24px 0;border:0}.markdown-body blockquote{padding:0 1em;color:#6a737d;border-left:.25em solid #dfe2e5}.markdown-body h1,.markdown-body h2{padding-bottom:.3em;border-bottom:1px solid #eaecef}.markdown-body blockquote>:first-child{margin-top:0}.markdown-body blockquote>:last-child{margin-bottom:0}.markdown-body h1,.markdown-body h2,.markdown-body h3,.markdown-body h4,.markdown-body h5,.markdown-body h6{margin-top:24px;margin-bottom:16px;font-weight:600;line-height:1.25}.markdown-body h1 .octicon-link,.markdown-body h2 .octicon-link,.markdown-body h3 .octicon-link,.markdown-body h4 .octicon-link,.markdown-body h5 .octicon-link,.markdown-body h6 .octicon-link{color:#1b1f23;vertical-align:middle;visibility:hidden}.markdown-body h1:hover .anchor,.markdown-body h2:hover .anchor,.markdown-body h3:hover .anchor,.markdown-body h4:hover .anchor,.markdown-body h5:hover .anchor,.markdown-body h6:hover .anchor{text-decoration:none}.markdown-body h1:hover .anchor .octicon-link,.markdown-body h2:hover .anchor .octicon-link,.markdown-body h3:hover .anchor .octicon-link,.markdown-body h4:hover .anchor .octicon-link,.markdown-body h5:hover .anchor .octicon-link,.markdown-body h6:hover .anchor .octicon-link{visibility:visible}.markdown-body h6{color:#6a737d}.markdown-body ol,.markdown-body ul{padding-left:2em}.markdown-body ol ol,.markdown-body ol ul,.markdown-body ul ol,.markdown-body ul ul{margin-top:0;margin-bottom:0}.markdown-body li>p{margin-top:16px}.markdown-body li+li{margin-top:.25em}.markdown-body dl{padding:0}.markdown-body dl dt{padding:0;margin-top:16px;font-size:1em;font-style:italic;font-weight:600}.markdown-body dl dd{padding:0 16px;margin-bottom:16px}.markdown-body table th{font-weight:600}.markdown-body table td,.markdown-body table th{padding:6px 13px;border:1px solid #dfe2e5}.markdown-body table tr{background-color:#fff;border-top:1px solid #c6cbd1}.markdown-body table tr:nth-child(2n){background-color:#f6f8fa}.markdown-body img{max-width:100%;box-sizing:content-box;background-color:#fff}.markdown-body code{padding:.2em 0;margin:0;font-size:85%;background-color:rgba(27,31,35,.05);border-radius:3px}.markdown-body code::after,.markdown-body code::before{letter-spacing:-.2em;content:"\00a0"}.markdown-body pre>code{padding:0;margin:0;font-size:100%;word-break:normal;white-space:pre;background:0 0;border:0}.markdown-body .highlight{margin-bottom:16px}.markdown-body .highlight pre{margin-bottom:0;word-break:normal}.markdown-body .highlight pre,.markdown-body pre{padding:16px;overflow:auto;font-size:85%;line-height:1.45;background-color:#f6f8fa;border-radius:3px}.markdown-body pre code{display:inline;max-width:auto;padding:0;margin:0;overflow:visible;line-height:inherit;word-wrap:normal;background-color:transparent;border:0}.markdown-body pre code::after,.markdown-body pre code::before{content:normal}.markdown-body .full-commit .btn-outline:not(:disabled):hover{color:#005cc5;border-color:#005cc5}.markdown-body kbd{display:inline-block;padding:3px 5px;font:11px SFMono-Regular,Consolas,"Liberation Mono",Menlo,Courier,monospace;line-height:10px;color:#444d56;vertical-align:middle;background-color:#fafbfc;border:1px solid #d1d5da;border-bottom-color:#c6cbd1;border-radius:3px;box-shadow:inset 0 -1px 0 #c6cbd1}.hljs,.katex .katex-html>.newline{display:block}.node text,.noteText,div.mermaidTooltip{font-family:'trebuchet ms',verdana,arial}.markdown-body :checked+.radio-label{position:relative;z-index:1;border-color:#0366d6}.markdown-body .task-list-item+.task-list-item{margin-top:3px}.markdown-body .task-list-item input{margin:0 .2em .25em -1.6em;vertical-align:middle}.markdown-body hr{border-bottom-color:#eee}.hljs{overflow-x:auto;padding:.5em;color:#333;background:#f8f8f8}.hljs-comment,.hljs-quote{color:#998;font-style:italic}.hljs-keyword,.hljs-selector-tag,.hljs-subst{color:#333;font-weight:700}.hljs-literal,.hljs-number,.hljs-tag .hljs-attr,.hljs-template-variable,.hljs-variable{color:teal}.hljs-doctag,.hljs-string{color:#d14}.hljs-section,.hljs-selector-id,.hljs-title{color:#900;font-weight:700}.hljs-subst{font-weight:400}.hljs-class .hljs-title,.hljs-type{color:#458;font-weight:700}.hljs-attribute,.hljs-name,.hljs-tag{color:navy;font-weight:400}.hljs-meta,.hljs-strong{font-weight:700}.hljs-link,.hljs-regexp{color:#009926}.hljs-bullet,.hljs-symbol{color:#990073}.hljs-built_in,.hljs-builtin-name{color:#0086b3}.hljs-meta{color:#999}.hljs-deletion{background:#fdd}.hljs-addition{background:#dfd}.hljs-emphasis{font-style:italic}.mermaid .label{color:#333}.node circle,.node ellipse,.node polygon,.node rect{fill:#ECECFF;stroke:#CCF;stroke-width:1px}.edgePath .path{stroke:#333}.edgeLabel{background-color:#e8e8e8}.cluster rect{fill:#ffffde!important;rx:4!important;stroke:#aa3!important;stroke-width:1px!important}.cluster text{fill:#333}.actor{stroke:#CCF;fill:#ECECFF}text.actor{fill:#000;stroke:none}.actor-line{stroke:grey}.messageLine0,.messageLine1{stroke-width:1.5;stroke-dasharray:"2 2";stroke:#333}#arrowhead{fill:#333}#crosshead path{fill:#333!important;stroke:#333!important}.messageText{fill:#333;stroke:none}.labelBox{stroke:#CCF;fill:#ECECFF}.labelText,.loopText{fill:#000;stroke:none}.loopLine{stroke-width:2;stroke-dasharray:"2 2";stroke:#CCF}.note{stroke:#aa3;fill:#fff5ad}.noteText{fill:#000;stroke:none;font-size:14px}.section{stroke:none;opacity:.2}.section0{fill:rgba(102,102,255,.49)}.section2{fill:#fff400}.section1,.section3{fill:#fff;opacity:.2}.sectionTitle0,.sectionTitle1,.sectionTitle2,.sectionTitle3{fill:#333}.sectionTitle{text-anchor:start;font-size:11px;text-height:14px}.grid .tick{stroke:#d3d3d3;opacity:.3;shape-rendering:crispEdges}.grid path{stroke-width:0}.today{fill:none;stroke:red;stroke-width:2px}.task{stroke-width:2}.taskText{text-anchor:middle;font-size:11px}.taskTextOutsideRight{fill:#000;text-anchor:start;font-size:11px}.taskTextOutsideLeft{fill:#000;text-anchor:end;font-size:11px}.taskText0,.taskText1,.taskText2,.taskText3{fill:#fff}.task0,.task1,.task2,.task3{fill:#8a90dd;stroke:#534fbc}.taskTextOutside0,.taskTextOutside1,.taskTextOutside2,.taskTextOutside3{fill:#000}.active0,.active1,.active2,.active3{fill:#bfc7ff;stroke:#534fbc}.activeText0,.activeText1,.activeText2,.activeText3{fill:#000!important}.done0,.done1,.done2,.done3{stroke:grey;fill:#d3d3d3;stroke-width:2}.doneText0,.doneText1,.doneText2,.doneText3{fill:#000!important}.crit0,.crit1,.crit2,.crit3{stroke:#f88;fill:red;stroke-width:2}.activeCrit0,.activeCrit1,.activeCrit2,.activeCrit3{stroke:#f88;fill:#bfc7ff;stroke-width:2}.doneCrit0,.doneCrit1,.doneCrit2,.doneCrit3{stroke:#f88;fill:#d3d3d3;stroke-width:2;cursor:pointer;shape-rendering:crispEdges}.activeCritText0,.activeCritText1,.activeCritText2,.activeCritText3,.doneCritText0,.doneCritText1,.doneCritText2,.doneCritText3{fill:#000!important}.titleText{text-anchor:middle;font-size:18px;fill:#000}.node text{font-size:14px}div.mermaidTooltip{position:absolute;text-align:center;max-width:200px;padding:2px;font-size:12px;background:#ffffde;border:1px solid #aa3;border-radius:2px;pointer-events:none;z-index:100}@font-face{font-family:KaTeX_AMS;font-style:normal;font-weight:400;src:url(fonts/KaTeX_AMS-Regular.woff2) format("woff2"),url(fonts/KaTeX_AMS-Regular.woff) format("woff"),url(fonts/KaTeX_AMS-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Caligraphic;font-style:normal;font-weight:700;src:url(fonts/KaTeX_Caligraphic-Bold.woff2) format("woff2"),url(fonts/KaTeX_Caligraphic-Bold.woff) format("woff"),url(fonts/KaTeX_Caligraphic-Bold.ttf) format("truetype")}@font-face{font-family:KaTeX_Caligraphic;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Caligraphic-Regular.woff2) format("woff2"),url(fonts/KaTeX_Caligraphic-Regular.woff) format("woff"),url(fonts/KaTeX_Caligraphic-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Fraktur;font-style:normal;font-weight:700;src:url(fonts/KaTeX_Fraktur-Bold.woff2) format("woff2"),url(fonts/KaTeX_Fraktur-Bold.woff) format("woff"),url(fonts/KaTeX_Fraktur-Bold.ttf) format("truetype")}@font-face{font-family:KaTeX_Fraktur;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Fraktur-Regular.woff2) format("woff2"),url(fonts/KaTeX_Fraktur-Regular.woff) format("woff"),url(fonts/KaTeX_Fraktur-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Main;font-style:normal;font-weight:700;src:url(fonts/KaTeX_Main-Bold.woff2) format("woff2"),url(fonts/KaTeX_Main-Bold.woff) format("woff"),url(fonts/KaTeX_Main-Bold.ttf) format("truetype")}@font-face{font-family:KaTeX_Main;font-style:italic;font-weight:700;src:url(fonts/KaTeX_Main-BoldItalic.woff2) format("woff2"),url(fonts/KaTeX_Main-BoldItalic.woff) format("woff"),url(fonts/KaTeX_Main-BoldItalic.ttf) format("truetype")}@font-face{font-family:KaTeX_Main;font-style:italic;font-weight:400;src:url(fonts/KaTeX_Main-Italic.woff2) format("woff2"),url(fonts/KaTeX_Main-Italic.woff) format("woff"),url(fonts/KaTeX_Main-Italic.ttf) format("truetype")}@font-face{font-family:KaTeX_Main;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Main-Regular.woff2) format("woff2"),url(fonts/KaTeX_Main-Regular.woff) format("woff"),url(fonts/KaTeX_Main-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Math;font-style:italic;font-weight:700;src:url(fonts/KaTeX_Math-BoldItalic.woff2) format("woff2"),url(fonts/KaTeX_Math-BoldItalic.woff) format("woff"),url(fonts/KaTeX_Math-BoldItalic.ttf) format("truetype")}@font-face{font-family:KaTeX_Math;font-style:italic;font-weight:400;src:url(fonts/KaTeX_Math-Italic.woff2) format("woff2"),url(fonts/KaTeX_Math-Italic.woff) format("woff"),url(fonts/KaTeX_Math-Italic.ttf) format("truetype")}@font-face{font-family:KaTeX_SansSerif;font-style:normal;font-weight:700;src:url(fonts/KaTeX_SansSerif-Bold.woff2) format("woff2"),url(fonts/KaTeX_SansSerif-Bold.woff) format("woff"),url(fonts/KaTeX_SansSerif-Bold.ttf) format("truetype")}@font-face{font-family:KaTeX_SansSerif;font-style:italic;font-weight:400;src:url(fonts/KaTeX_SansSerif-Italic.woff2) format("woff2"),url(fonts/KaTeX_SansSerif-Italic.woff) format("woff"),url(fonts/KaTeX_SansSerif-Italic.ttf) format("truetype")}@font-face{font-family:KaTeX_SansSerif;font-style:normal;font-weight:400;src:url(fonts/KaTeX_SansSerif-Regular.woff2) format("woff2"),url(fonts/KaTeX_SansSerif-Regular.woff) format("woff"),url(fonts/KaTeX_SansSerif-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Script;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Script-Regular.woff2) format("woff2"),url(fonts/KaTeX_Script-Regular.woff) format("woff"),url(fonts/KaTeX_Script-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Size1;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Size1-Regular.woff2) format("woff2"),url(fonts/KaTeX_Size1-Regular.woff) format("woff"),url(fonts/KaTeX_Size1-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Size2;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Size2-Regular.woff2) format("woff2"),url(fonts/KaTeX_Size2-Regular.woff) format("woff"),url(fonts/KaTeX_Size2-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Size3;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Size3-Regular.woff2) format("woff2"),url(fonts/KaTeX_Size3-Regular.woff) format("woff"),url(fonts/KaTeX_Size3-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Size4;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Size4-Regular.woff2) format("woff2"),url(fonts/KaTeX_Size4-Regular.woff) format("woff"),url(fonts/KaTeX_Size4-Regular.ttf) format("truetype")}@font-face{font-family:KaTeX_Typewriter;font-style:normal;font-weight:400;src:url(fonts/KaTeX_Typewriter-Regular.woff2) format("woff2"),url(fonts/KaTeX_Typewriter-Regular.woff) format("woff"),url(fonts/KaTeX_Typewriter-Regular.ttf) format("truetype")}.katex{font:400 1.21em KaTeX_Main,Times New Roman,serif;line-height:1.2;text-indent:0;text-rendering:auto}.katex .mathit,.katex .textit{font-style:italic}.katex *{-ms-high-contrast-adjust:none!important}.katex .katex-mathml{border:0;clip:rect(1px,1px,1px,1px);height:1px;overflow:hidden;padding:0;position:absolute;width:1px}.katex .base{position:relative;white-space:nowrap;width:min-content}.katex .base,.katex .strut{display:inline-block}.katex .textbf{font-weight:700}.katex .textrm{font-family:KaTeX_Main}.katex .textsf{font-family:KaTeX_SansSerif}.katex .texttt{font-family:KaTeX_Typewriter}.katex .mathdefault{font-family:KaTeX_Math;font-style:italic}.katex .mathit{font-family:KaTeX_Main}.katex .mathrm{font-style:normal}.katex .mathbf{font-family:KaTeX_Main;font-weight:700}.katex .boldsymbol{font-family:KaTeX_Math;font-style:italic;font-weight:700}.katex .amsrm,.katex .mathbb,.katex .textbb{font-family:KaTeX_AMS}.katex .mathcal{font-family:KaTeX_Caligraphic}.katex .mathfrak,.katex .textfrak{font-family:KaTeX_Fraktur}.katex .mathtt{font-family:KaTeX_Typewriter}.katex .mathscr,.katex .textscr{font-family:KaTeX_Script}.katex .mathsf,.katex .textsf{font-family:KaTeX_SansSerif}.katex .mathboldsf,.katex .textboldsf{font-family:KaTeX_SansSerif;font-weight:700}.katex .mathitsf,.katex .textitsf{font-family:KaTeX_SansSerif;font-style:italic}.katex .mainrm{font-family:KaTeX_Main;font-style:normal}.katex .vlist-t{display:inline-table;table-layout:fixed}.katex .vlist-r{display:table-row}.katex .vlist{display:table-cell;position:relative;vertical-align:bottom}.katex .vlist>span{display:block;height:0;position:relative}.katex .vlist>span>span{display:inline-block}.katex .vlist>span>.pstrut{overflow:hidden;width:0}.katex .vlist-t2{margin-right:-2px}.katex .vlist-s{display:table-cell;font-size:1px;min-width:2px;vertical-align:bottom;width:2px}.katex .clap>.fix,.katex .fontsize-ensurer,.katex .hdashline,.katex .llap>.fix,.katex .mfrac .frac-line,.katex .mspace,.katex .nulldelimiter,.katex .rlap>.fix,.katex .rule,.katex .sizing{display:inline-block}.katex .msupsub{text-align:left}.katex .accent>.vlist-t,.katex .mfrac>span>span,.katex .mtable .col-align-c>.vlist-t,.katex .op-limits>.vlist-t{text-align:center}.katex .mfrac .frac-line{border-bottom-style:solid;width:100%}.katex .hdashline,.katex .hline,.katex .mfrac .frac-line,.katex .overline .overline-line,.katex .rule,.katex .underline .underline-line{min-height:1px}.katex .clap,.katex .llap,.katex .rlap{position:relative;width:0}.katex .clap>.inner,.katex .llap>.inner,.katex .rlap>.inner{position:absolute}.katex .accent .accent-body,.katex .delimcenter,.katex .op-symbol,.katex .rule{position:relative}.katex .llap>.inner{right:0}.katex .clap>.inner,.katex .rlap>.inner{left:0}.katex .clap>.inner>span{margin-left:-50%;margin-right:50%}.katex .rule{border:0 solid}.katex .hline,.katex .overline .overline-line,.katex .underline .underline-line{border-bottom-style:solid;display:inline-block;width:100%}.katex .hdashline{border-bottom-style:dashed;width:100%}.katex .sqrt>.root{margin-left:.27777778em;margin-right:-.55555556em}.katex .fontsize-ensurer.reset-size1.size1,.katex .sizing.reset-size1.size1{font-size:1em}.katex .fontsize-ensurer.reset-size1.size2,.katex .sizing.reset-size1.size2{font-size:1.2em}.katex .fontsize-ensurer.reset-size1.size3,.katex .sizing.reset-size1.size3{font-size:1.4em}.katex .fontsize-ensurer.reset-size1.size4,.katex .sizing.reset-size1.size4{font-size:1.6em}.katex .fontsize-ensurer.reset-size1.size5,.katex .sizing.reset-size1.size5{font-size:1.8em}.katex .fontsize-ensurer.reset-size1.size6,.katex .sizing.reset-size1.size6{font-size:2em}.katex .fontsize-ensurer.reset-size1.size7,.katex .sizing.reset-size1.size7{font-size:2.4em}.katex .fontsize-ensurer.reset-size1.size8,.katex .sizing.reset-size1.size8{font-size:2.88em}.katex .fontsize-ensurer.reset-size1.size9,.katex .sizing.reset-size1.size9{font-size:3.456em}.katex .fontsize-ensurer.reset-size1.size10,.katex .sizing.reset-size1.size10{font-size:4.148em}.katex .fontsize-ensurer.reset-size1.size11,.katex .sizing.reset-size1.size11{font-size:4.976em}.katex .fontsize-ensurer.reset-size2.size1,.katex .sizing.reset-size2.size1{font-size:.83333333em}.katex .fontsize-ensurer.reset-size2.size2,.katex .sizing.reset-size2.size2{font-size:1em}.katex .fontsize-ensurer.reset-size2.size3,.katex .sizing.reset-size2.size3{font-size:1.16666667em}.katex .fontsize-ensurer.reset-size2.size4,.katex .sizing.reset-size2.size4{font-size:1.33333333em}.katex .fontsize-ensurer.reset-size2.size5,.katex .sizing.reset-size2.size5{font-size:1.5em}.katex .fontsize-ensurer.reset-size2.size6,.katex .sizing.reset-size2.size6{font-size:1.66666667em}.katex .fontsize-ensurer.reset-size2.size7,.katex .sizing.reset-size2.size7{font-size:2em}.katex .fontsize-ensurer.reset-size2.size8,.katex .sizing.reset-size2.size8{font-size:2.4em}.katex .fontsize-ensurer.reset-size2.size9,.katex .sizing.reset-size2.size9{font-size:2.88em}.katex .fontsize-ensurer.reset-size2.size10,.katex .sizing.reset-size2.size10{font-size:3.45666667em}.katex .fontsize-ensurer.reset-size2.size11,.katex .sizing.reset-size2.size11{font-size:4.14666667em}.katex .fontsize-ensurer.reset-size3.size1,.katex .sizing.reset-size3.size1{font-size:.71428571em}.katex .fontsize-ensurer.reset-size3.size2,.katex .sizing.reset-size3.size2{font-size:.85714286em}.katex .fontsize-ensurer.reset-size3.size3,.katex .sizing.reset-size3.size3{font-size:1em}.katex .fontsize-ensurer.reset-size3.size4,.katex .sizing.reset-size3.size4{font-size:1.14285714em}.katex .fontsize-ensurer.reset-size3.size5,.katex .sizing.reset-size3.size5{font-size:1.28571429em}.katex .fontsize-ensurer.reset-size3.size6,.katex .sizing.reset-size3.size6{font-size:1.42857143em}.katex .fontsize-ensurer.reset-size3.size7,.katex .sizing.reset-size3.size7{font-size:1.71428571em}.katex .fontsize-ensurer.reset-size3.size8,.katex .sizing.reset-size3.size8{font-size:2.05714286em}.katex .fontsize-ensurer.reset-size3.size9,.katex .sizing.reset-size3.size9{font-size:2.46857143em}.katex .fontsize-ensurer.reset-size3.size10,.katex .sizing.reset-size3.size10{font-size:2.96285714em}.katex .fontsize-ensurer.reset-size3.size11,.katex .sizing.reset-size3.size11{font-size:3.55428571em}.katex .fontsize-ensurer.reset-size4.size1,.katex .sizing.reset-size4.size1{font-size:.625em}.katex .fontsize-ensurer.reset-size4.size2,.katex .sizing.reset-size4.size2{font-size:.75em}.katex .fontsize-ensurer.reset-size4.size3,.katex .sizing.reset-size4.size3{font-size:.875em}.katex .fontsize-ensurer.reset-size4.size4,.katex .sizing.reset-size4.size4{font-size:1em}.katex .fontsize-ensurer.reset-size4.size5,.katex .sizing.reset-size4.size5{font-size:1.125em}.katex .fontsize-ensurer.reset-size4.size6,.katex .sizing.reset-size4.size6{font-size:1.25em}.katex .fontsize-ensurer.reset-size4.size7,.katex .sizing.reset-size4.size7{font-size:1.5em}.katex .fontsize-ensurer.reset-size4.size8,.katex .sizing.reset-size4.size8{font-size:1.8em}.katex .fontsize-ensurer.reset-size4.size9,.katex .sizing.reset-size4.size9{font-size:2.16em}.katex .fontsize-ensurer.reset-size4.size10,.katex .sizing.reset-size4.size10{font-size:2.5925em}.katex .fontsize-ensurer.reset-size4.size11,.katex .sizing.reset-size4.size11{font-size:3.11em}.katex .fontsize-ensurer.reset-size5.size1,.katex .sizing.reset-size5.size1{font-size:.55555556em}.katex .fontsize-ensurer.reset-size5.size2,.katex .sizing.reset-size5.size2{font-size:.66666667em}.katex .fontsize-ensurer.reset-size5.size3,.katex .sizing.reset-size5.size3{font-size:.77777778em}.katex .fontsize-ensurer.reset-size5.size4,.katex .sizing.reset-size5.size4{font-size:.88888889em}.katex .fontsize-ensurer.reset-size5.size5,.katex .sizing.reset-size5.size5{font-size:1em}.katex .fontsize-ensurer.reset-size5.size6,.katex .sizing.reset-size5.size6{font-size:1.11111111em}.katex .fontsize-ensurer.reset-size5.size7,.katex .sizing.reset-size5.size7{font-size:1.33333333em}.katex .fontsize-ensurer.reset-size5.size8,.katex .sizing.reset-size5.size8{font-size:1.6em}.katex .fontsize-ensurer.reset-size5.size9,.katex .sizing.reset-size5.size9{font-size:1.92em}.katex .fontsize-ensurer.reset-size5.size10,.katex .sizing.reset-size5.size10{font-size:2.30444444em}.katex .fontsize-ensurer.reset-size5.size11,.katex .sizing.reset-size5.size11{font-size:2.76444444em}.katex .fontsize-ensurer.reset-size6.size1,.katex .sizing.reset-size6.size1{font-size:.5em}.katex .fontsize-ensurer.reset-size6.size2,.katex .sizing.reset-size6.size2{font-size:.6em}.katex .fontsize-ensurer.reset-size6.size3,.katex .sizing.reset-size6.size3{font-size:.7em}.katex .fontsize-ensurer.reset-size6.size4,.katex .sizing.reset-size6.size4{font-size:.8em}.katex .fontsize-ensurer.reset-size6.size5,.katex .sizing.reset-size6.size5{font-size:.9em}.katex .fontsize-ensurer.reset-size6.size6,.katex .sizing.reset-size6.size6{font-size:1em}.katex .fontsize-ensurer.reset-size6.size7,.katex .sizing.reset-size6.size7{font-size:1.2em}.katex .fontsize-ensurer.reset-size6.size8,.katex .sizing.reset-size6.size8{font-size:1.44em}.katex .fontsize-ensurer.reset-size6.size9,.katex .sizing.reset-size6.size9{font-size:1.728em}.katex .fontsize-ensurer.reset-size6.size10,.katex .sizing.reset-size6.size10{font-size:2.074em}.katex .fontsize-ensurer.reset-size6.size11,.katex .sizing.reset-size6.size11{font-size:2.488em}.katex .fontsize-ensurer.reset-size7.size1,.katex .sizing.reset-size7.size1{font-size:.41666667em}.katex .fontsize-ensurer.reset-size7.size2,.katex .sizing.reset-size7.size2{font-size:.5em}.katex .fontsize-ensurer.reset-size7.size3,.katex .sizing.reset-size7.size3{font-size:.58333333em}.katex .fontsize-ensurer.reset-size7.size4,.katex .sizing.reset-size7.size4{font-size:.66666667em}.katex .fontsize-ensurer.reset-size7.size5,.katex .sizing.reset-size7.size5{font-size:.75em}.katex .fontsize-ensurer.reset-size7.size6,.katex .sizing.reset-size7.size6{font-size:.83333333em}.katex .fontsize-ensurer.reset-size7.size7,.katex .sizing.reset-size7.size7{font-size:1em}.katex .fontsize-ensurer.reset-size7.size8,.katex .sizing.reset-size7.size8{font-size:1.2em}.katex .fontsize-ensurer.reset-size7.size9,.katex .sizing.reset-size7.size9{font-size:1.44em}.katex .fontsize-ensurer.reset-size7.size10,.katex .sizing.reset-size7.size10{font-size:1.72833333em}.katex .fontsize-ensurer.reset-size7.size11,.katex .sizing.reset-size7.size11{font-size:2.07333333em}.katex .fontsize-ensurer.reset-size8.size1,.katex .sizing.reset-size8.size1{font-size:.34722222em}.katex .fontsize-ensurer.reset-size8.size2,.katex .sizing.reset-size8.size2{font-size:.41666667em}.katex .fontsize-ensurer.reset-size8.size3,.katex .sizing.reset-size8.size3{font-size:.48611111em}.katex .fontsize-ensurer.reset-size8.size4,.katex .sizing.reset-size8.size4{font-size:.55555556em}.katex .fontsize-ensurer.reset-size8.size5,.katex .sizing.reset-size8.size5{font-size:.625em}.katex .fontsize-ensurer.reset-size8.size6,.katex .sizing.reset-size8.size6{font-size:.69444444em}.katex .fontsize-ensurer.reset-size8.size7,.katex .sizing.reset-size8.size7{font-size:.83333333em}.katex .fontsize-ensurer.reset-size8.size8,.katex .sizing.reset-size8.size8{font-size:1em}.katex .fontsize-ensurer.reset-size8.size9,.katex .sizing.reset-size8.size9{font-size:1.2em}.katex .fontsize-ensurer.reset-size8.size10,.katex .sizing.reset-size8.size10{font-size:1.44027778em}.katex .fontsize-ensurer.reset-size8.size11,.katex .sizing.reset-size8.size11{font-size:1.72777778em}.katex .fontsize-ensurer.reset-size9.size1,.katex .sizing.reset-size9.size1{font-size:.28935185em}.katex .fontsize-ensurer.reset-size9.size2,.katex .sizing.reset-size9.size2{font-size:.34722222em}.katex .fontsize-ensurer.reset-size9.size3,.katex .sizing.reset-size9.size3{font-size:.40509259em}.katex .fontsize-ensurer.reset-size9.size4,.katex .sizing.reset-size9.size4{font-size:.46296296em}.katex .fontsize-ensurer.reset-size9.size5,.katex .sizing.reset-size9.size5{font-size:.52083333em}.katex .fontsize-ensurer.reset-size9.size6,.katex .sizing.reset-size9.size6{font-size:.5787037em}.katex .fontsize-ensurer.reset-size9.size7,.katex .sizing.reset-size9.size7{font-size:.69444444em}.katex .fontsize-ensurer.reset-size9.size8,.katex .sizing.reset-size9.size8{font-size:.83333333em}.katex .fontsize-ensurer.reset-size9.size9,.katex .sizing.reset-size9.size9{font-size:1em}.katex .fontsize-ensurer.reset-size9.size10,.katex .sizing.reset-size9.size10{font-size:1.20023148em}.katex .fontsize-ensurer.reset-size9.size11,.katex .sizing.reset-size9.size11{font-size:1.43981481em}.katex .fontsize-ensurer.reset-size10.size1,.katex .sizing.reset-size10.size1{font-size:.24108004em}.katex .fontsize-ensurer.reset-size10.size2,.katex .sizing.reset-size10.size2{font-size:.28929605em}.katex .fontsize-ensurer.reset-size10.size3,.katex .sizing.reset-size10.size3{font-size:.33751205em}.katex .fontsize-ensurer.reset-size10.size4,.katex .sizing.reset-size10.size4{font-size:.38572806em}.katex .fontsize-ensurer.reset-size10.size5,.katex .sizing.reset-size10.size5{font-size:.43394407em}.katex .fontsize-ensurer.reset-size10.size6,.katex .sizing.reset-size10.size6{font-size:.48216008em}.katex .fontsize-ensurer.reset-size10.size7,.katex .sizing.reset-size10.size7{font-size:.57859209em}.katex .fontsize-ensurer.reset-size10.size8,.katex .sizing.reset-size10.size8{font-size:.69431051em}.katex .fontsize-ensurer.reset-size10.size9,.katex .sizing.reset-size10.size9{font-size:.83317261em}.katex .fontsize-ensurer.reset-size10.size10,.katex .sizing.reset-size10.size10{font-size:1em}.katex .fontsize-ensurer.reset-size10.size11,.katex .sizing.reset-size10.size11{font-size:1.19961427em}.katex .fontsize-ensurer.reset-size11.size1,.katex .sizing.reset-size11.size1{font-size:.20096463em}.katex .fontsize-ensurer.reset-size11.size2,.katex .sizing.reset-size11.size2{font-size:.24115756em}.katex .fontsize-ensurer.reset-size11.size3,.katex .sizing.reset-size11.size3{font-size:.28135048em}.katex .fontsize-ensurer.reset-size11.size4,.katex .sizing.reset-size11.size4{font-size:.32154341em}.katex .fontsize-ensurer.reset-size11.size5,.katex .sizing.reset-size11.size5{font-size:.36173633em}.katex .fontsize-ensurer.reset-size11.size6,.katex .sizing.reset-size11.size6{font-size:.40192926em}.katex .fontsize-ensurer.reset-size11.size7,.katex .sizing.reset-size11.size7{font-size:.48231511em}.katex .fontsize-ensurer.reset-size11.size8,.katex .sizing.reset-size11.size8{font-size:.57877814em}.katex .fontsize-ensurer.reset-size11.size9,.katex .sizing.reset-size11.size9{font-size:.69453376em}.katex .fontsize-ensurer.reset-size11.size10,.katex .sizing.reset-size11.size10{font-size:.83360129em}.katex .fontsize-ensurer.reset-size11.size11,.katex .sizing.reset-size11.size11{font-size:1em}.katex .delimsizing.size1{font-family:KaTeX_Size1}.katex .delimsizing.size2{font-family:KaTeX_Size2}.katex .delimsizing.size3{font-family:KaTeX_Size3}.katex .delimsizing.size4{font-family:KaTeX_Size4}.katex .delimsizing.mult .delim-size1>span{font-family:KaTeX_Size1}.katex .delimsizing.mult .delim-size4>span{font-family:KaTeX_Size4}.katex .nulldelimiter{width:.12em}.katex .op-symbol.small-op{font-family:KaTeX_Size1}.katex .op-symbol.large-op{font-family:KaTeX_Size2}.katex .accent .accent-body:not(.accent-full){width:0}.katex .overlay{display:block}.katex .mtable .vertical-separator{border-right:.05em solid;display:inline-block;margin:0 -.025em;min-width:1px}.katex .mtable .vs-dashed{border-right:.05em dashed}.katex .mtable .arraycolsep{display:inline-block}.katex .mtable .col-align-l>.vlist-t{text-align:left}.katex .mtable .col-align-r>.vlist-t{text-align:right}.katex .svg-align{text-align:left}.katex .mover,.katex .munder,.katex .x-arrow,.katex-display,div[data-role=mermaid]{text-align:center}.katex svg{display:block;fill:currentColor;fill-opacity:1;fill-rule:nonzero;height:inherit;position:absolute;stroke:currentColor;stroke-dasharray:none;stroke-dashoffset:0;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-opacity:1;stroke-width:1;width:100%}.katex .hide-tail,.katex .stretchy{overflow:hidden;position:relative;width:100%}.katex svg path{stroke:none}.katex .stretchy{display:block}.katex .stretchy:after,.katex .stretchy:before{content:""}.katex .brace-center,.katex .brace-left,.katex .brace-right,.katex .halfarrow-left,.katex .halfarrow-right{position:absolute;overflow:hidden}.katex .halfarrow-left{left:0;width:50.2%}.katex .halfarrow-right{right:0;width:50.2%}.katex .brace-left{left:0;width:25.1%}.katex .brace-center{left:25%;width:50%}.katex .brace-right{right:0;width:25.1%}.katex .x-arrow-pad{padding:0 .5em}.katex .boxpad{padding:0 .3em}.katex .fbox{border:.04em solid #000;box-sizing:border-box}.katex .fcolorbox{border:.04em solid;box-sizing:border-box}.katex .cancel-pad{padding:0 .2em}.katex .cancel-lap{margin-left:-.2em;margin-right:-.2em}.katex .sout{border-bottom-style:solid;border-bottom-width:.08em}.katex-display{display:block;margin:1em 0}.katex-display>.katex{display:block;text-align:center;white-space:nowrap}.katex-display>.katex>.katex-html{display:block;position:relative}.katex-display>.katex>.katex-html>.tag{position:absolute;right:0}body{margin:0;padding:0}.markdown-body{min-width:256px;max-width:978px;margin:0 auto;padding:20px;font-size:14px}.markdown-body h1{font-size:2.25em}.markdown-body h2{font-size:1.75em}.markdown-body h3{font-size:1.5em}.markdown-body h4{font-size:1.25em}.markdown-body h5,.markdown-body h6{font-size:1em}div[data-role=mermaid] svg{height:auto}hr.footnotes-sep{margin:64px 0 32px;height:1px}.footnotes{font-size:90%;padding-left:16px}li.footnote-item>p{margin:8px 0}.danger,.info,.success,.warning{padding:15px;margin-bottom:20px;border:1px solid transparent;border-radius:4px}.danger>p:last-child,.info>p:last-child,.success>p:last-child,.warning>p:last-child{margin-bottom:0}.success{color:#3c763d;background-color:#dff0d8;border-color:#d6e9c6}.info{color:#31708f;background-color:#d9edf7;border-color:#bce8f1}.warning{color:#8a6d3b;background-color:#fcf8e3;border-color:#faebcc}.danger{color:#a94442;background-color:#f2dede;border-color:#ebccd1}abbr[title]{cursor:help;border-bottom:1px dotted #777}ul.table-of-contents li{margin:4px 0}.markdown-body table{border-spacing:0;border-collapse:collapse;width:auto;display:inline-block;overflow:hidden}.markdown-body table td,.markdown-body table th{word-break:break-all}
-->

DataX MysqlWriter


1 快速介绍

MysqlWriter 插件实现了写入数据到 Mysql 主库的目的表的功能。在底层实现上, MysqlWriter 通过 JDBC 连接远程 Mysql 数据库,并执行相应的 insert into ... 或者 ( replace into ...) 的 sql 语句将数据写入 Mysql,内部会分批次提交入库,需要数据库本身采用 innodb 引擎。

MysqlWriter 面向ETL开发工程师,他们使用 MysqlWriter 从数仓导入数据到 Mysql。同时 MysqlWriter 亦可以作为数据迁移工具为DBA等用户提供服务。

2 实现原理

MysqlWriter 通过 DataX 框架获取 Reader 生成的协议数据,根据你配置的 writeMode 生成

  • insert into...(当主键/唯一性索引冲突时会写不进去冲突的行)
或者
  • replace into...(没有遇到主键/唯一性索引冲突时,与 insert into 行为一致,冲突时会用新行替换原有行所有字段) 的语句写入数据到 Mysql。出于性能考虑,采用了 PreparedStatement + Batch,并且设置了:rewriteBatchedStatements=true,将数据缓冲到线程上下文 Buffer 中,当 Buffer 累计到预定阈值时,才发起写入请求。
注意:目的表所在数据库必须是主库才能写入数据;整个任务至少需要具备 insert/replace into...的权限,是否需要其他权限,取决于你任务配置中在 preSql 和 postSql 中指定的语句。

3 功能说明

3.1 配置样例

  • 这里使用一份从内存产生到 Mysql 导入的数据。
{
"job": {
"setting": {
"speed": {
"channel": 1
}
},
"content": [
{
"reader": {
"name": "streamreader",
"parameter": {
"column" : [
{
"value": "DataX",
"type": "string"
},
{
"value": 19880808,
"type": "long"
},
{
"value": "1988-08-08 08:08:08",
"type": "date"
},
{
"value": true,
"type": "bool"
},
{
"value": "test",
"type": "bytes"
}
],
"sliceRecordCount": 1000
}
},
"writer": {
"name": "mysqlwriter",
"parameter": {
"writeMode": "insert",
"username": "root",
"password": "root",
"column": [
"id",
"name"
],
"session": [
"set session sql_mode='ANSI'"
],
"preSql": [
"delete from test"
],
"connection": [
{
"jdbcUrl": "jdbc:mysql://127.0.0.1:3306/datax?useUnicode=true&characterEncoding=gbk",
"table": [
"test"
]
}
]
}
}
}
]
}
}

3.2 参数说明

  • jdbcUrl

    • 描述:目的数据库的 JDBC 连接信息。作业运行时,DataX 会在你提供的 jdbcUrl 后面追加如下属性:yearIsDateType=false&zeroDateTimeBehavior=convertToNull&rewriteBatchedStatements=true

      注意:1、在一个数据库上只能配置一个 jdbcUrl 值。这与 MysqlReader 支持多个备库探测不同,因为此处不支持同一个数据库存在多个主库的情况(双主导入数据情况)
      2、jdbcUrl按照Mysql官方规范,并可以填写连接附加控制信息,比如想指定连接编码为 gbk ,则在 jdbcUrl 后面追加属性 useUnicode=true&characterEncoding=gbk。具体请参看 Mysql官方文档或者咨询对应 DBA。
    • 必选:是

    • 默认值:无

  • username

    • 描述:目的数据库的用户名

    • 必选:是

    • 默认值:无

  • password

    • 描述:目的数据库的密码

    • 必选:是

    • 默认值:无

  • table

    • 描述:目的表的表名称。支持写入一个或者多个表。当配置为多张表时,必须确保所有表结构保持一致。

      注意:table 和 jdbcUrl 必须包含在 connection 配置单元中
    • 必选:是

    • 默认值:无

  • column

    • 描述:目的表需要写入数据的字段,字段之间用英文逗号分隔。例如: "column": ["id","name","age"]。如果要依次写入全部列,使用表示, 例如: "column": [""]。

      **column配置项必须指定,不能留空!**
      
           注意:1、我们强烈不推荐你这样配置,因为当你目的表字段个数、类型等有改动时,你的任务可能运行不正确或者失败
      2、 column 不能配置任何常量值
    • 必选:是

    • 默认值:否

  • session

    • 描述: DataX在获取Mysql连接时,执行session指定的SQL语句,修改当前connection session属性

    • 必须: 否

    • 默认值: 空

  • preSql

    • 描述:写入数据到目的表前,会先执行这里的标准语句。如果 Sql 中有你需要操作到的表名称,请使用 @table 表示,这样在实际执行 Sql 语句时,会对变量按照实际表名称进行替换。比如你的任务是要写入到目的端的100个同构分表(表名称为:datax_00,datax01, ... datax_98,datax_99),并且你希望导入数据前,先对表中数据进行删除操作,那么你可以这样配置:"preSql":["delete from 表名"],效果是:在执行到每个表写入数据前,会先执行对应的 delete from 对应表名称

    • 必选:否

    • 默认值:无

  • postSql

    • 描述:写入数据到目的表后,会执行这里的标准语句。(原理同 preSql )

    • 必选:否

    • 默认值:无

  • writeMode

    • 描述:控制写入数据到目标表采用 insert into 或者 replace into 或者 ON DUPLICATE KEY UPDATE 语句

    • 必选:是

    • 所有选项:insert/replace/update

    • 默认值:insert

  • batchSize

    • 描述:一次性批量提交的记录数大小,该值可以极大减少DataX与Mysql的网络交互次数,并提升整体吞吐量。但是该值设置过大可能会造成DataX运行进程OOM情况。

    • 必选:否

    • 默认值:1024

3.3 类型转换

类似 MysqlReader ,目前 MysqlWriter 支持大部分 Mysql 类型,但也存在部分个别类型没有支持的情况,请注意检查你的类型。

下面列出 MysqlWriter 针对 Mysql 类型转换列表:

DataX 内部类型 Mysql 数据类型
Long int, tinyint, smallint, mediumint, int, bigint, year
Double float, double, decimal
String varchar, char, tinytext, text, mediumtext, longtext
Date date, datetime, timestamp, time
Boolean bit, bool
Bytes tinyblob, mediumblob, blob, longblob, varbinary
  • bit类型目前是未定义类型转换

4 性能报告

4.1 环境准备

4.1.1 数据特征

建表语句:

CREATE TABLE `datax_mysqlwriter_perf_00` (
`biz_order_id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'id',
`key_value` varchar(4000) NOT NULL COMMENT 'Key-value的内容',
`gmt_create` datetime NOT NULL COMMENT '创建时间',
`gmt_modified` datetime NOT NULL COMMENT '修改时间',
`attribute_cc` int(11) DEFAULT NULL COMMENT '防止并发修改的标志',
`value_type` int(11) NOT NULL DEFAULT '0' COMMENT '类型',
`buyer_id` bigint(20) DEFAULT NULL COMMENT 'buyerid',
`seller_id` bigint(20) DEFAULT NULL COMMENT 'seller_id',
PRIMARY KEY (`biz_order_id`,`value_type`),
KEY `idx_biz_vertical_gmtmodified` (`gmt_modified`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='datax perf test'

单行记录类似于:

key_value: ;orderIds:20148888888,2014888888813800;
gmt_create: 2011-09-24 11:07:20
gmt_modified: 2011-10-24 17:56:34
attribute_cc: 1
value_type: 3
buyer_id: 8888888
seller_id: 1

4.1.2 机器参数

  • 执行DataX的机器参数为:

    1. cpu: 24核 Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz
    2. mem: 48GB
    3. net: 千兆双网卡
    4. disc: DataX 数据不落磁盘,不统计此项
  • Mysql数据库机器参数为:

    1. cpu: 32核 Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz
    2. mem: 256GB
    3. net: 千兆双网卡
    4. disc: BTWL419303E2800RGN INTEL SSDSC2BB800G4 D2010370

4.1.3 DataX jvm 参数

-Xms1024m -Xmx1024m -XX:+HeapDumpOnOutOfMemoryError

4.2 测试报告

4.2.1 单表测试报告

通道数 批量提交行数 DataX速度(Rec/s) DataX流量(MB/s) DataX机器网卡流出流量(MB/s) DataX机器运行负载 DB网卡进入流量(MB/s) DB运行负载 DB TPS
1 128 5319 0.260 0.580 0.05 0.620 0.5 50
1 512 14285 0.697 1.6 0.12 1.6 0.6 28
1 1024 17241 0.842 1.9 0.20 1.9 0.6 16
1 2048 31250 1.49 2.8 0.15 3.0 0.8 15
1 4096 31250 1.49 3.5 0.20 3.6 0.8 8
4 128 11764 0.574 1.5 0.21 1.6 0.8 112
4 512 30769 1.47 3.5 0.3 3.6 0.9 88
4 1024 50000 2.38 5.4 0.3 5.5 1.0 66
4 2048 66666 3.18 7.0 0.3 7.1 1.37 46
4 4096 80000 3.81 7.3 0.5 7.3 1.40 26
8 128 17777 0.868 2.9 0.28 2.9 0.8 200
8 512 57142 2.72 8.5 0.5 8.5 0.70 159
8 1024 88888 4.24 12.2 0.9 12.4 1.0 108
8 2048 133333 6.36 14.7 0.9 14.7 1.0 81
8 4096 166666 7.95 19.5 0.9 19.5 3.0 45
16 128 32000 1.53 3.3 0.6 3.4 0.88 401
16 512 106666 5.09 16.1 0.9 16.2 2.16 260
16 1024 173913 8.29 22.1 1.5 22.2 4.5 200
16 2048 228571 10.90 28.6 1.61 28.7 4.60 128
16 4096 246153 11.74 31.1 1.65 31.2 4.66 57
32 1024 246153 11.74 30.5 3.17 30.7 12.10 270

说明:

  1. 这里的单表,主键类型为 bigint(20),自增。
  2. batchSize 和 通道个数,对性能影响较大。
  3. 16通道,4096批量提交时,出现 full gc 2次。

4.2.2 分表测试报告(2个分库,每个分库4张分表,共计8张分表)

通道数 批量提交行数 DataX速度(Rec/s) DataX流量(MB/s) DataX机器网卡流出流量(MB/s) DataX机器运行负载 DB网卡进入流量(MB/s) DB运行负载 DB TPS
8 128 26764 1.28 2.9 0.5 3.0 0.8 209
8 512 95180 4.54 10.5 0.7 10.9 0.8 188
8 1024 94117 4.49 12.3 0.6 12.4 1.09 120
8 2048 133333 6.36 19.4 0.9 19.5 1.35 85
8 4096 191692 9.14 22.1 1.0 22.2 1.45 45

4.2.3 分表测试报告(2个分库,每个分库8张分表,共计16张分表)

通道数 批量提交行数 DataX速度(Rec/s) DataX流量(MB/s) DataX机器网卡流出流量(MB/s) DataX机器运行负载 DB网卡进入流量(MB/s) DB运行负载 DB TPS
16 128 50124 2.39 5.6 0.40 6.0 2.42 378
16 512 155084 7.40 18.6 1.30 18.9 2.82 325
16 1024 177777 8.48 24.1 1.43 25.5 3.5 233
16 2048 289382 13.8 33.1 2.5 33.5 4.5 150
16 4096 326451 15.52 33.7 1.5 33.9 4.3 80

4.2.4 性能测试小结

  1. 批量提交行数(batchSize)对性能影响很大,当 batchSize>=512 之后,单线程写入速度能达到每秒写入一万行
  2. batchSize>=512 的基础上,随着通道数的增加(通道数<32),速度呈线性比增加。
  3. 通常不建议写入数据库时,通道个数 >32

5 约束限制

FAQ


Q: MysqlWriter 执行 postSql 语句报错,那么数据导入到目标数据库了吗?

A: DataX 导入过程存在三块逻辑,pre 操作、导入操作、post 操作,其中任意一环报错,DataX 作业报错。由于 DataX 不能保证在同一个事务完成上述几个操作,因此有可能数据已经落入到目标端。


Q: 按照上述说法,那么有部分脏数据导入数据库,如果影响到线上数据库怎么办?

A: 目前有两种解法,第一种配置 pre 语句,该 sql 可以清理当天导入数据, DataX 每次导入时候可以把上次清理干净并导入完整数据。第二种,向临时表导入数据,完成后再 rename 到线上表。


Q: 上面第二种方法可以避免对线上数据造成影响,那我具体怎样操作?

A: 可以配置临时表导入

DataX-MysqlWriter 插件文档的更多相关文章

  1. DataX-MysqlReader 插件文档

    :first-child{margin-top:0!important}.markdown-body>:last-child{margin-bottom:0!important}.markdow ...

  2. Bootstrap FileInput 多图上传插件 文档属性说明

    Bootstrap FileInput 多图上传插件   原文链接:http://blog.csdn.net/misterwho/article/details/72886248?utm_source ...

  3. bootstraptable插件文档的坑

    1.事件onCheck中文档参数为row, $element正确的顺序为$element,row eg: $Table.on('check.bs.table', function ($element, ...

  4. FullPage.js全屏插件文档及使用方法

    简介 fullPage.js是一个基于jQuery的全屏滚动插件,它能够很方便.很轻松的制作出全屏网站 下载地址 下载地址 相关示例:基于fullpage.js实现的360全屏滑动效果 支持功能 支持 ...

  5. qt 工具下的dump工具导出文档出现异常解决方案

    今天一直认为qt环境下的dumpcpp 和dumpdoc两个导出工具很好用,可以今天在导出MSChart组件的类方法文档时,虽然导出成功了,但是导出的结果却是令人失望.自己也不知道如何能够正确导出,就 ...

  6. Spring Boot文档

    本文来自于springboot官方文档 地址:https://docs.spring.io/spring-boot/docs/current/reference/html/ Spring Boot参考 ...

  7. Jenkins Hackfest 用户体验文档报告

    Jenkins 技术文档是我们项目的重要组成部分,因为它是正确使用 Jenkins 的关键.好的文档可以指导用户,并鼓励选择好的实现方式.这是用户体验的关键部分.在最近的 Jenkins UI/UX ...

  8. 【HTML5】嵌入另一张HTML文档、通过插件嵌入内容、嵌入数字表现形式

    1.嵌入另一张HTML文档 iframe 元素允许在现有的HTML文档中嵌入另一张文档.下面代码展示了iframe元素的用法: <!DOCTYPE html> <html lang= ...

  9. Swagger-UI 基于REST的API测试/文档类插件

    现在多数的项目开发中,网站和移动端都需要进行数据交互和对接,这少不了使用REST编写API接口这种场景.例如我目前的工作,移动端交由了另一团队开发,不同开发小组之间就需要以规范和文档作为标准和协作基础 ...

随机推荐

  1. window执行python文件

    @echo offD:cd D:\pythonstart python2 del.pyexit

  2. Object-c学习笔记十八-----NSPredicate

    Cocoa提供了一个类NSPredicate类,该类主要用于指定过滤器的条件,该对象可以准确的描述所需条件,对每个对象通过谓词进行筛选,判断是否与条件相匹配.谓词表示计算真值或假值的函数. NSPre ...

  3. HDFS概念

  4. 3d爱心代码

    <!doctype html> <html> <head> <meta charset="UTF-8"> <title> ...

  5. H3C 电路交换连接模型

  6. H3C 802.11无线网络的介质访问控制

  7. mysql怎么创建,删除,查看索引?

    mysql是一个开源的应用非常广泛的数据库.mysql里面的索引能利用利用指针,能够大大提高查询效率.特别是当数据量非常大,查询涉及多个表时,使用索引往往能使查询速度加快成千上万倍.那么,怎么创建索引 ...

  8. Python--day69--ORM的F查询和Q查询

    F查询和Q查询 F查询 在上面所有的例子中,我们构造的过滤器都只是将字段值与某个常量做比较.如果我们要对两个字段的值做比较,那该怎么做呢? Django 提供 F() 来做这样的比较.F() 的实例可 ...

  9. 2012年NOIP普及组复赛题解

    题目涉及算法: 质因数分解:入门: 寻宝:模拟: 摆花:动态规划: 文化之旅:搜索. 质因数分解 题目链接:https://www.luogu.org/problem/P1075 这道题目只需要开个 ...

  10. H5 移动端获取当前位置

    3种方法:1.H5自带的方法,获取经纬度2.通过地图提供的JS.获取位置3.通过微信的API(这个需要公众号 / 小程序) 1.通过H5自带的获取经纬度的方法 优点: 需要引用的资源较少,H5自带的方 ...