107 lines
3.4 KiB
HTML
107 lines
3.4 KiB
HTML
<!doctype html>
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<html>
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<head>
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<meta charset="utf-8" />
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<meta name="viewport" content="width=device-width, initial-scale=1" />
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<link
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rel="stylesheet"
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href="https://cdnjs.cloudflare.com/ajax/libs/github-markdown-css/5.2.0/github-markdown-dark.min.css"
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/>
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<title>haunt98 posts</title>
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</head>
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<style>
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.markdown-body {
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box-sizing: border-box;
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min-width: 200px;
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max-width: 980px;
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margin: 0 auto;
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padding: 45px;
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}
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@media (max-width: 767px) {
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.markdown-body {
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padding: 15px;
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}
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}
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</style>
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<body class="markdown-body">
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<div><a href="index.html">Index</a></div>
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<h1>
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<a
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id="user-content-incident-come-and-go"
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class="anchor"
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aria-hidden="true"
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href="#incident-come-and-go"
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><span aria-hidden="true" class="octicon octicon-link"></span></a
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>Incident come and go
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</h1>
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<p>This is collect of all incidents I created in the past :(</p>
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<h2>
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<a
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id="user-content-service-starts-with-empty-port"
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class="anchor"
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aria-hidden="true"
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href="#service-starts-with-empty-port"
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><span aria-hidden="true" class="octicon octicon-link"></span></a
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>Service starts with empty port
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</h2>
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<p>Because all configs is read from file.</p>
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<p>
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But the port config is empty -> So when service inits, it use that
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empty port somehow.
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</p>
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<p>
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<strong>Solution</strong>: For some configs, make sure to failed first if
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it's empty.
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</p>
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<h2>
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<a
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id="user-content-race-condition-of-series-of-apis"
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class="anchor"
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aria-hidden="true"
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href="#race-condition-of-series-of-apis"
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><span aria-hidden="true" class="octicon octicon-link"></span></a
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>Race condition of series of APIs
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</h2>
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<p>For example I have 2 APIs:</p>
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<ul>
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<li>API upload: allow user to upload image</li>
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<li>API submit: submit data to server</li>
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</ul>
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<p>
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API upload is slow, it takes 10s to finish. API submit is fast, only takes
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2s.
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</p>
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<p>
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The problem is submit use data from upload too. When user calls API
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upload, image is stored in cache. When user calls API submit, it use
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whatever image is stored in cache.
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</p>
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<p>It's when the fun begins.</p>
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<p>
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Imagine user Trong already upload image. So he is ready to submit. But for
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the same time, he re-call API upload to upload another image too.
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</p>
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<p>
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So if API upload is finished first, which is kinda impossible (U know
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upload file is not fast right?), everything right. But for most cases, API
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submit is finished first. It means Trong's data is submitted with the old
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image. Then API upload is finished, it will replace the old image with the
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new one.So the old one, aka image in submitted data, is gone.
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</p>
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<p>Chaos right there!</p>
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<p>
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<strong>Solution</strong>: Use a lock, if user enter API upload, lock it
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to prevent user call other APIs. Rememeber to unlock after finished
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</p>
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<div>
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Feel free to ask me via
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<a href="mailto:hauvipapro+posts@gmail.com">email</a> or
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<a rel="me" href="https://hachyderm.io/@haunguyen">Mastodon</a>. Source
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code is available on
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<a href="https://github.com/haunt98/posts-go">GitHub</a>
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</div>
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</body>
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</html>
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