-
Notifications
You must be signed in to change notification settings - Fork 0
/
rabbitmqxi-lie-di-er-pian.html
334 lines (281 loc) · 25.4 KB
/
rabbitmqxi-lie-di-er-pian.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="author" content="CatsAction" />
<meta property="og:type" content="article" />
<meta name="twitter:card" content="summary">
<meta name="keywords" content="MQ, Go, RabbitMQ, " />
<meta property="og:title" content="RabbitMQ系列第二篇 - 如何保证消息可靠性"/>
<meta property="og:url" content="./rabbitmqxi-lie-di-er-pian.html" />
<meta property="og:description" content="在RabbitMQ使用中，如果一个任务分发给一个Worker，而Worker执行到一半就退出了，这时如何保证消息不丢失呢？下面一起看看RabbitMQ保证消息可靠传输机制。 可靠传输机制 消息持久化 消息确认（Consumer Acknowledgements and Publisher Confirms） 集群和高可用模式 消息补偿机制（确认及重传） 消息持久化 RabbitMQ消息默认存储在内存，如果重启，或者宕机，那样消息就丢失了。消息持久化之后，消息会被写入硬盘，在服务恢复的时候再加载回来。 消息持久化需要同时持久化Exchange，Queue，Message。下面是Golang简单的例子。 func (ch *Channel) ExchangeDeclare(name, kind string, durable, autoDelete, internal, noWait bool, args Table) error func (ch *Channel) QueueDeclare(name string, durable …" />
<meta property="og:site_name" content="CatsAction's blog" />
<meta property="og:article:author" content="CatsAction" />
<meta property="og:article:published_time" content="2019-01-09T00:00:00+08:00" />
<meta name="twitter:title" content="RabbitMQ系列第二篇 - 如何保证消息可靠性">
<meta name="twitter:description" content="在RabbitMQ使用中，如果一个任务分发给一个Worker，而Worker执行到一半就退出了，这时如何保证消息不丢失呢？下面一起看看RabbitMQ保证消息可靠传输机制。 可靠传输机制 消息持久化 消息确认（Consumer Acknowledgements and Publisher Confirms） 集群和高可用模式 消息补偿机制（确认及重传） 消息持久化 RabbitMQ消息默认存储在内存，如果重启，或者宕机，那样消息就丢失了。消息持久化之后，消息会被写入硬盘，在服务恢复的时候再加载回来。 消息持久化需要同时持久化Exchange，Queue，Message。下面是Golang简单的例子。 func (ch *Channel) ExchangeDeclare(name, kind string, durable, autoDelete, internal, noWait bool, args Table) error func (ch *Channel) QueueDeclare(name string, durable …">
<title>RabbitMQ系列第二篇 - 如何保证消息可靠性 ·
CatsAction's blog
</title>
<link href="//netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css" rel="stylesheet">
<link rel="icon" type="image/x-icon" href="./theme/image/logo.ico" />
<link rel="stylesheet" type="text/css" href="./theme/css/elegant.prod.css" media="screen">
<link rel="stylesheet" type="text/css" href="./theme/css/custom.css" media="screen">
</head>
<body>
<div id="content">
<div class="navbar navbar-static-top">
<div class="navbar-inner">
<div class="container-fluid">
<a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</a>
<a class="brand" href="./"><span class=site-name>CatsAction's blog</span></a>
<div class="nav-collapse collapse">
<ul class="nav pull-right top-menu">
<li >
<a href=
.
>Home</a>
</li>
<li ><a href="./categories.html">Categories</a></li>
<li ><a href="./tags.html">Tags</a></li>
<li ><a href="./archives.html">Archives</a></li>
<li><form class="navbar-search" action="./search.html" onsubmit="return validateForm(this.elements['q'].value);"> <input type="text" class="search-query" placeholder="Search" name="q" id="tipue_search_input"></form></li>
</ul>
</div>
</div>
</div>
</div>
<div class="container-fluid">
<div class="row-fluid">
<div class="span1"></div>
<div class="span10">
<article itemscope>
<div class="row-fluid">
<header class="page-header span10 offset2">
<h1>
<a href="./rabbitmqxi-lie-di-er-pian.html">
RabbitMQ系列第二篇
<small class="subtitle">
如何保证消息可靠性
</small>
</a>
</h1>
</header>
</div>
<div class="row-fluid">
<div class="span8 offset2 article-content">
<p><em>在RabbitMQ使用中，如果一个任务分发给一个Worker，而Worker执行到一半就退出了，这时如何保证消息不丢失呢？下面一起看看RabbitMQ保证消息可靠传输机制。</em></p>
<h4>可靠传输机制</h4>
<ul>
<li>消息持久化</li>
<li>消息确认（Consumer Acknowledgements and Publisher Confirms）</li>
<li>集群和高可用模式</li>
<li>消息补偿机制（确认及重传）</li>
</ul>
<h4>消息持久化</h4>
<p>RabbitMQ消息默认存储在内存，如果重启，或者宕机，那样消息就丢失了。消息持久化之后，消息会被写入硬盘，在服务恢复的时候再加载回来。
消息持久化需要同时持久化Exchange，Queue，Message。下面是Golang简单的例子。</p>
<div class="highlight"><pre><span></span><span class="kd">func</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">*</span><span class="nx">Channel</span><span class="p">)</span> <span class="nx">ExchangeDeclare</span><span class="p">(</span><span class="nx">name</span><span class="p">,</span> <span class="nx">kind</span> <span class="kt">string</span><span class="p">,</span> <span class="nx">durable</span><span class="p">,</span> <span class="nx">autoDelete</span><span class="p">,</span> <span class="nx">internal</span><span class="p">,</span> <span class="nx">noWait</span> <span class="kt">bool</span><span class="p">,</span> <span class="nx">args</span> <span class="nx">Table</span><span class="p">)</span> <span class="kt">error</span>
<span class="kd">func</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">*</span><span class="nx">Channel</span><span class="p">)</span> <span class="nx">QueueDeclare</span><span class="p">(</span><span class="nx">name</span> <span class="kt">string</span><span class="p">,</span> <span class="nx">durable</span><span class="p">,</span> <span class="nx">autoDelete</span><span class="p">,</span> <span class="nx">exclusive</span><span class="p">,</span> <span class="nx">noWait</span> <span class="kt">bool</span><span class="p">,</span> <span class="nx">args</span> <span class="nx">Table</span><span class="p">)</span> <span class="p">(</span><span class="nx">Queue</span><span class="p">,</span> <span class="kt">error</span><span class="p">)</span>
<span class="kd">func</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">*</span><span class="nx">Channel</span><span class="p">)</span> <span class="nx">Publish</span><span class="p">(</span><span class="nx">exchange</span><span class="p">,</span> <span class="nx">key</span> <span class="kt">string</span><span class="p">,</span> <span class="nx">mandatory</span><span class="p">,</span> <span class="nx">immediate</span> <span class="kt">bool</span><span class="p">,</span> <span class="nx">msg</span> <span class="nx">Publishing</span><span class="p">)</span> <span class="kt">error</span>
<span class="kd">type</span> <span class="nx">Publishing</span> <span class="kd">struct</span> <span class="p">{</span>
<span class="c1">// Application or exchange specific fields,</span>
<span class="c1">// the headers exchange will inspect this field.</span>
<span class="nx">Headers</span> <span class="nx">Table</span>
<span class="c1">// Properties</span>
<span class="nx">ContentType</span> <span class="kt">string</span> <span class="c1">// MIME content type</span>
<span class="nx">ContentEncoding</span> <span class="kt">string</span> <span class="c1">// MIME content encoding</span>
<span class="nx">DeliveryMode</span> <span class="kt">uint8</span> <span class="c1">// Transient (0 or 1) or Persistent (2)</span>
<span class="nx">Priority</span> <span class="kt">uint8</span> <span class="c1">// 0 to 9</span>
<span class="nx">CorrelationId</span> <span class="kt">string</span> <span class="c1">// correlation identifier</span>
<span class="nx">ReplyTo</span> <span class="kt">string</span> <span class="c1">// address to to reply to (ex: RPC)</span>
<span class="nx">Expiration</span> <span class="kt">string</span> <span class="c1">// message expiration spec</span>
<span class="nx">MessageId</span> <span class="kt">string</span> <span class="c1">// message identifier</span>
<span class="nx">Timestamp</span> <span class="nx">time</span><span class="p">.</span><span class="nx">Time</span> <span class="c1">// message timestamp</span>
<span class="nx">Type</span> <span class="kt">string</span> <span class="c1">// message type name</span>
<span class="nx">UserId</span> <span class="kt">string</span> <span class="c1">// creating user id - ex: "guest"</span>
<span class="nx">AppId</span> <span class="kt">string</span> <span class="c1">// creating application id</span>
<span class="c1">// The application specific payload of the message</span>
<span class="nx">Body</span> <span class="p">[]</span><span class="kt">byte</span>
<span class="p">}</span>
</pre></div>
<p><code>ExchangeDeclare</code>和<code>QueueDeclare</code>的<code>durable</code>设为<code>true</code>，将创建的Exchange和Queue持久化。发送消息时，将<code>Publishing</code>
的<code>DeliveryMode</code>模式设置为2，将对应的消息持久化。下面是Golang发送消息持久化的简单示例。</p>
<div class="highlight"><pre><span></span><span class="nx">err</span> <span class="p">=</span> <span class="nx">ch</span><span class="p">.</span><span class="nx">Publish</span><span class="p">(</span>
<span class="s">""</span><span class="p">,</span> <span class="c1">// exchange</span>
<span class="nx">q</span><span class="p">.</span><span class="nx">Name</span><span class="p">,</span> <span class="c1">// routing key</span>
<span class="kc">false</span><span class="p">,</span> <span class="c1">// mandatory</span>
<span class="kc">false</span><span class="p">,</span>
<span class="nx">amqp</span><span class="p">.</span><span class="nx">Publishing</span> <span class="p">{</span>
<span class="nx">DeliveryMode</span><span class="p">:</span> <span class="nx">amqp</span><span class="p">.</span><span class="nx">Persistent</span><span class="p">,</span>
<span class="nx">ContentType</span><span class="p">:</span> <span class="s">"text/plain"</span><span class="p">,</span>
<span class="nx">Body</span><span class="p">:</span> <span class="p">[]</span><span class="nb">byte</span><span class="p">(</span><span class="nx">body</span><span class="p">),</span>
<span class="p">})</span>
<span class="k">if</span> <span class="nx">err</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
<span class="nx">log</span><span class="p">.</span><span class="nx">Fatalf</span><span class="p">(</span><span class="s">"%s: %s"</span><span class="p">,</span> <span class="nx">msg</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span>
<span class="p">}</span>
</pre></div>
<h4>消息确认</h4>
<p>消息持久化到硬盘需要一个过程，如果在小段时间中发生异常，消息扔将丢失。如果设置消息分发即删除，像开篇提到的场景，Worker异常退出的情况，消息也会丢失。
RabbitMQ通过<strong>Consumer Acknowledgements and Publisher Confirms</strong>确保消息被成功分发和处理。<br/>
默认情况下，RabbitMQ将自动确认，这样无法保证消息被Work处理成功。需要将自动确认设置为<code>false</code>，处理完相应消息时手动确认。下面是Go手动确认相关API。</p>
<div class="highlight"><pre><span></span><span class="kd">func</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">*</span><span class="nx">Channel</span><span class="p">)</span> <span class="nx">Consume</span><span class="p">(</span><span class="nx">queue</span><span class="p">,</span> <span class="nx">consumer</span> <span class="kt">string</span><span class="p">,</span> <span class="nx">autoAck</span><span class="p">,</span> <span class="nx">exclusive</span><span class="p">,</span> <span class="nx">noLocal</span><span class="p">,</span> <span class="nx">noWait</span> <span class="kt">bool</span><span class="p">,</span> <span class="nx">args</span> <span class="nx">Table</span><span class="p">)</span> <span class="p">(</span><span class="o"><-</span><span class="kd">chan</span> <span class="nx">Delivery</span><span class="p">,</span> <span class="kt">error</span><span class="p">)</span>
<span class="c1">// Delivery是Consumer收到消息的结构体定义</span>
<span class="kd">func</span> <span class="p">(</span><span class="nx">d</span> <span class="nx">Delivery</span><span class="p">)</span> <span class="nx">Ack</span><span class="p">(</span><span class="nx">multiple</span> <span class="kt">bool</span><span class="p">)</span> <span class="kt">error</span>
<span class="kd">func</span> <span class="p">(</span><span class="nx">d</span> <span class="nx">Delivery</span><span class="p">)</span> <span class="nx">Nack</span><span class="p">(</span><span class="nx">multiple</span><span class="p">,</span> <span class="nx">requeue</span> <span class="kt">bool</span><span class="p">)</span> <span class="kt">error</span>
<span class="kd">func</span> <span class="p">(</span><span class="nx">d</span> <span class="nx">Delivery</span><span class="p">)</span> <span class="nx">Reject</span><span class="p">(</span><span class="nx">requeue</span> <span class="kt">bool</span><span class="p">)</span> <span class="kt">error</span>
</pre></div>
<p>将<code>Consumer</code>的<code>autoAck</code>设置成<code>false</code>关闭自动确认。<code>Ack</code>手动给一个肯定的确认，<code>multiple</code>设置为<code>true</code>表示批量确认。<code>Nack和Reject</code>手动给一个否定的确认，
<code>requeue</code>设置为<code>true</code>消息将被分发给其他Consumer。下面是一个Go手动确认的示例。</p>
<div class="highlight"><pre><span></span><span class="nx">msgs</span><span class="p">,</span> <span class="nx">err</span> <span class="o">:=</span> <span class="nx">ch</span><span class="p">.</span><span class="nx">Consume</span><span class="p">(</span>
<span class="nx">q</span><span class="p">.</span><span class="nx">Name</span><span class="p">,</span> <span class="c1">// queue</span>
<span class="s">""</span><span class="p">,</span> <span class="c1">// consumer</span>
<span class="kc">false</span><span class="p">,</span> <span class="c1">// auto-ack</span>
<span class="kc">false</span><span class="p">,</span> <span class="c1">// exclusive</span>
<span class="kc">false</span><span class="p">,</span> <span class="c1">// no-local</span>
<span class="kc">false</span><span class="p">,</span> <span class="c1">// no-wait</span>
<span class="kc">nil</span><span class="p">,</span> <span class="c1">// args</span>
<span class="p">)</span>
<span class="nx">failOnError</span><span class="p">(</span><span class="nx">err</span><span class="p">,</span> <span class="s">"Failed to register a consumer"</span><span class="p">)</span>
<span class="nx">forever</span> <span class="o">:=</span> <span class="nb">make</span><span class="p">(</span><span class="kd">chan</span> <span class="kt">bool</span><span class="p">)</span>
<span class="k">go</span> <span class="kd">func</span><span class="p">()</span> <span class="p">{</span>
<span class="k">for</span> <span class="nx">d</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">msgs</span> <span class="p">{</span>
<span class="nx">log</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"Received a message: %s"</span><span class="p">,</span> <span class="nx">d</span><span class="p">.</span><span class="nx">Body</span><span class="p">)</span>
<span class="nx">dot_count</span> <span class="o">:=</span> <span class="nx">bytes</span><span class="p">.</span><span class="nx">Count</span><span class="p">(</span><span class="nx">d</span><span class="p">.</span><span class="nx">Body</span><span class="p">,</span> <span class="p">[]</span><span class="nb">byte</span><span class="p">(</span><span class="s">"."</span><span class="p">))</span>
<span class="nx">t</span> <span class="o">:=</span> <span class="nx">time</span><span class="p">.</span><span class="nx">Duration</span><span class="p">(</span><span class="nx">dot_count</span><span class="p">)</span>
<span class="nx">time</span><span class="p">.</span><span class="nx">Sleep</span><span class="p">(</span><span class="nx">t</span> <span class="o">*</span> <span class="nx">time</span><span class="p">.</span><span class="nx">Second</span><span class="p">)</span>
<span class="nx">log</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"Done"</span><span class="p">)</span>
<span class="nx">d</span><span class="p">.</span><span class="nx">Ack</span><span class="p">(</span><span class="kc">false</span><span class="p">)</span>
<span class="p">}</span>
<span class="p">}()</span>
<span class="nx">log</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">" [*] Waiting for messages. To exit press CTRL+C"</span><span class="p">)</span>
<span class="o"><-</span><span class="nx">forever</span>
</pre></div>
<p><code>Publisher Confirms</code>和<code>Consumer Acknowledgements</code>机制差不多，当消息被成功发送到Queue，如果需要持久化，成功持久化到硬盘，
此时Broker将给Publisher确认。<br/>
保证Publisher发送消息成功的方式还有事务（tx transaction）。事务是AMQP支持的标准。不过事务过重，影响了MQ吞吐量。</p>
<h4>集群和高可用模式</h4>
<p>后面的篇章将会基于Docker验证RabbitMQ的集群和高可用，也会讲解基本配置和常用的运维命令或工具，这里就先略过。</p>
<h4>消息补偿机制</h4>
<p>生产环境和实际网络实际情况是复杂的，不可能保证100%消息不丢失。因此Publisher需要确保在消息丢失下的重传机制。</p>
<hr />
<aside>
<nav>
<ul class="articles-timeline">
<li class="previous-article">« <a href="./rabbitmqxi-lie-di-yi-pian.html"
title="Previous: RabbitMQ系列第一篇 - 基本概念和常见工作模式">RabbitMQ系列第一篇 <small class="subtitle">基本概念和常见工作模式</small></a></li>
<li class="next-article"><a href="./rabbitmqxi-lie-di-san-pian.html"
title="Next: RabbitMQ系列第三篇 - 分布式部署">RabbitMQ系列第三篇 <small class="subtitle">分布式部署</small></a> »</li>
</ul>
</nav>
</aside>
</div>
<section id="article-sidebar" class="span2">
<h4>Published</h4>
<time itemprop="dateCreated" datetime="2019-01-09T00:00:00+08:00"> 1
9, 2019</time>
<!---->
<h4>Category</h4>
<a class="category-link"
href="./categories.html#rabbitmq-ref">RabbitMQ</a>
<h4>Tags</h4>
<ul class="list-of-tags tags-in-article">
<li><a href="./tags.html#go-ref">Go
<span>1</span>
</a></li>
<li><a href="./tags.html#mq-ref">MQ
<span>3</span>
</a></li>
</ul>
<h4>Stay in Touch</h4>
<div id="sidebar-social-link">
<a href="mailto:[email protected]" title="My Email Address" target="_blank" rel="nofollow noopener noreferrer">
<svg xmlns="http://www.w3.org/2000/svg" aria-label="Mail" role="img" viewBox="0 0 512 512"><rect width="512" height="512" rx="15%" fill="#328cff"/><path d="m250 186c-46 0-69 35-69 74 0 44 29 72 68 72 43 0 73-32 73-75 0-44-34-71-72-71zm-1-37c30 0 57 13 77 33 0-22 35-22 35 1v150c-1 10 10 16 16 9 25-25 54-128-14-187-64-56-149-47-195-15-48 33-79 107-49 175 33 76 126 99 182 76 28-12 41 26 12 39-45 19-168 17-225-82-38-68-36-185 67-248 78-46 182-33 244 32 66 69 62 197-2 246-28 23-71 1-71-32v-11c-20 20-47 32-77 32-57 0-108-51-108-108 0-58 51-110 108-110" fill="#fff"/></svg>
</a>
<a href="https://github.com/boyaziqi" title="catsaction Github Repository" target="_blank" rel="nofollow noopener noreferrer">
<svg xmlns="http://www.w3.org/2000/svg" aria-label="GitHub" role="img" viewBox="0 0 512 512"><rect width="512" height="512" rx="15%" fill="#1B1817"/><path fill="#fff" d="M335 499c14 0 12 17 12 17H165s-2-17 12-17c13 0 16-6 16-12l-1-50c-71 16-86-28-86-28-12-30-28-37-28-37-24-16 1-16 1-16 26 2 40 26 40 26 22 39 59 28 74 22 2-17 9-28 16-35-57-6-116-28-116-126 0-28 10-51 26-69-3-6-11-32 3-67 0 0 21-7 70 26 42-12 86-12 128 0 49-33 70-26 70-26 14 35 6 61 3 67 16 18 26 41 26 69 0 98-60 120-117 126 10 8 18 24 18 48l-1 70c0 6 3 12 16 12z"/></svg>
</a>
<a href="https://www.linkedin.com/feed/" title="My LinkedIn" target="_blank" rel="nofollow noopener noreferrer">
<svg xmlns="http://www.w3.org/2000/svg" aria-label="LinkedIn" role="img" viewBox="0 0 512 512" fill="#fff"><rect width="512" height="512" rx="15%" fill="#0077b5"/><circle cx="142" cy="138" r="37"/><path stroke="#fff" stroke-width="66" d="M244 194v198M142 194v198"/><path d="M276 282c0-20 13-40 36-40 24 0 33 18 33 45v105h66V279c0-61-32-89-76-89-34 0-51 19-59 32"/></svg>
</a>
</div>
<h4>Friendship Links</h4>
<ul class="list-of-tags tags-in-article">
<li>
<a href="https://leetcode-cn.com/" title="力扣中国站点" target="_blank" rel="nofollow noopener noreferrer">
LeetCode
</a>
</li>
<li>
<a href="https://coolshell.cn/about" title="陈皓酷壳" target="_blank" rel="nofollow noopener noreferrer">
CoolShell
</a>
</li>
<li>
<a href="https://yikun.github.io/" title="姜毅坤博客" target="_blank" rel="nofollow noopener noreferrer">
Yikun
</a>
</li>
<li>
<a href="https://www.nowcoder.com/" title="牛客网" target="_blank" rel="nofollow noopener noreferrer">
牛客网
</a>
</li>
</ul>
</section>
</div>
</article>
</div>
<div class="span1"></div>
</div>
</div>
</div>
<footer>
<div>
<span class="site-name">CatsAction's blog</span> - It's a wonderful world
</div>
<div id="fpowered">
Powered by: <a href="http://getpelican.com/" title="Pelican Home Page" target="_blank" rel="nofollow noopener noreferrer">Pelican</a>
Theme: <a href="https://elegant.oncrashreboot.com/" title="Theme Elegant Home Page" target="_blank" rel="nofollow noopener noreferrer">Elegant</a>
</div>
</footer> <script src="//code.jquery.com/jquery.min.js"></script>
<script src="//netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/js/bootstrap.min.js"></script>
<script>
function validateForm(query)
{
return (query.length > 0);
}
</script>
<script>
(function () {
if (window.location.hash.match(/^#comment-\d+$/)) {
$('#comment_thread').collapse('show');
}
})();
window.onhashchange=function(){
if (window.location.hash.match(/^#comment-\d+$/))
window.location.reload(true);
}
$('#comment_thread').on('shown', function () {
var link = document.getElementById('comment-accordion-toggle');
var old_innerHTML = link.innerHTML;
$(link).fadeOut(200, function() {
$(this).text('Click here to hide comments').fadeIn(200);
});
$('#comment_thread').on('hidden', function () {
$(link).fadeOut(200, function() {
$(this).text(old_innerHTML).fadeIn(200);
});
})
})
</script>
</body>
<!-- Theme: Elegant built for Pelican
License : MIT -->
</html>