varnish 配置文件分享(sens杨 注释)

前言：
varnish 为目前新兴起来的软件，由于中文文档比较少，配置文件比较复杂，所以在运用起来也是特别的费劲。一个偶然的机会在一个群里，有位varnish高手（ sens杨 ）发表了一篇他对varnish配置文件理解的文档。对于学者来说很有价值。所以转载了过来。

原文如下：

varnish配置文件原文地址:http://groups.drupal.org/node/63203

注：红色字体是英文的直接翻译，有些地方翻译的不好
绿色部分是一些思考，这个配置对自身的业务配置的很详细，现在对除了cookie和TTL那部分外其他可以理解80%，慢慢学习体会

1. backend default {
2. .host = "127.0.0.1";
3. .port = "8008";
4. .connect_timeout = 600s;
5. .first_byte_timeout = 600s;
6. .between_bytes_timeout = 600s;
7. }
8. backend lighttpd {
9. .host = "127.0.0.1";
10. .port = "81";
11. .connect_timeout = 600s;
12. .first_byte_timeout = 600s;
13. .between_bytes_timeout = 600s;
14. }
15. acl techmission_internal {
16. "localhost";
17. "127.0.0.1";
18. }
19. sub vcl_recv {
20. // Allow a grace period for offering "stale" data in case backend lags (http://varnish-cache.org/wiki/VCLExampleGrace)
21. // 如果backend数据滞后，允许为“过时”数据提供一个宽松期
22. set req.grace = 5m;
23. // block outside world from our test sites
24. // 阻止非自己说测试网站（的数据访问）
25. if ((req.http.host ~ "www.domain1.org|www.domain2.org") && !(client.ip ~ techmission_internal) && !(req.url ~ "^/ad|^/files")) {
26. error 403 "Forbidden";
27. }
28. if((req.url ~ "/server-status" || req.url ~ "/whm-server-status") && !(client.ip ~ techmission_internal)) {
29. error 404 "Not Found";
30. }
31. // add ping url to test Varnish status
32. // 增加ping URL测试varnish状态（这个功能使用大部分vcl都没配置，可以增加一个监控状态）
33. if (req.request == "GET" && req.url ~ "/varnish-ping") {
34. error 200 "OK";
35. }
36. /* Normalize host header to reduce variation in cache */
37. // 使host头规范化，以减少在cache中变化（这个为什么会说变化呢？）
38. if (req.http.host == "domain.org" && req.url !~ "^/blogs") {
39. set req.http.host = "www.domain.org";
40. }
41. /* Normalize Accept-Encoding to reduce effects of Vary: Accept-Encoding
42. (cf. http://varnish-cache.org/wiki/FAQ/Compression)
43. Also note that Vary: User-Agent is considered harmful
44. (cf. http://www.mail-archive.com/varnish-misc@projects.linpro.no/msg03296.html) */
45. //规范化Accept-Encoding以减少Vary：Accept-Encoding影响（cf），也要注意Vary: User-Agent认为是有害的
46. if (req.http.Accept-Encoding) {
47. //if先判断是否可以存在，是为了缩小处理范围？
48. //看到的其他大部分配置直接就下面了，没有先判断Accept-Encoding是否存在，这点可以再考虑考虑
49. //现在有req.can_gzip参数了，判断客户端是否接受压缩代码传输
50. if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg)$") {
51. // Don't compress already-compressed files
52. remove req.http.Accept-Encoding;
53. }
54. elsif (req.http.Accept-Encoding ~ "gzip") {
55. set req.http.Accept-Encoding = "gzip";
56. }
57. elsif (req.http.Accept-Encoding ~ "deflate") {
58. set req.http.Accept-Encoding = "deflate";
59. }
60. else {
61. // unknown algorithm
62. // 不了解运算
63. remove req.http.Accept-Encoding;
64. }
65. }
66. // Remove has_js and Google Analytics __* cookies. Also remove collapsiblock cookies.
67. //删除has_js和谷歌统计__*的cookies，同时删除collapsiblock cookies
68. set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(__[a-z]+|__utma_a2a|has_js|collapsiblock)=[^;]*", "");
69. // Remove JSESSIONID cookie from ChristianVolunteering.org static files and pages that are same for all users
70. //从ChristianVolunteering.org静态文件和网页中删除JSESSIONID cookie，所有的用户是一样（处理）的
71. if (req.http.host ~ "christianvolunteering.org" &&
72. (req.url ~ "^/$" ||
73. req.url ~ "(searchform|advancedsearch|shorttermmissions|recruitvolunteers|volunteergettingstarted|virtualvolunteer|organizationsearch|abs-bible-outreach|ab*ecutive-volunteers|abs-traveling-engagement-center|churchinstructions|sitemap|city|virtual|organizationlistings|orglistings7407|technology|volunteerlistings|forgotpassword|churchvolunteer|churchvolunteering|servicetrip|region|citysitemap|searchformadv|personalitytest|groupvolunteering|disasterreliefvolunteering|disasterrelief|internships|christiangapyear|about|FAQs|bookrecommendations|contact|pressrelease|training|volunteerstart|volunteerstories|articles)\.jsp$" ||
74. req.url ~ "org/org[0-9]+\.jsp$" ||
75. req.url ~ "org/opp[0-9]+\.jsp$" ||
76. req.url ~ "orglistings[0-9]+\.jsp$" ||
77. req.url ~ "org/[^/]+\.jsp$" ||
78. req.url ~ "volunteer/[^/]+\.jsp$")
79. ) {
80. set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(JSESSIONID)=[^;]*", "");
81. }
82. // Remove a ";" prefix, if present.
83. //如果有”;”前缀，则删除
84. set req.http.Cookie = regsub(req.http.Cookie, "^;\s*", "");
85. // Remove empty cookies.
86. // 删除空cookies
87. if (req.http.Cookie ~ "^\s*$") {
88. unset req.http.Cookie;
89. }
90. // exclude umjobs and gospelpedia test sites
91. // 排除umjos和gospelpedia测试站点
92. if (req.http.host ~ "domain1.org" || req.http.host ~ "domain2.org") {
93. return (pass);
94. }
95. // exclude the cron and supercron pages
96. // 排除cron和supercron网页
97. if (req.url ~ "cron.php") {
98. return (pass);
99. }
100. // exclude dynamic pages (as did Boost)
101. // 排除动态网页（也是提高（处理））
102. if (req.http.host ~ "domain.org" && req.url ~ "^/(user/login|user/password|user/register|logout|cart|post-blog|site-feedback|cgi-bin/webscr|redirect-home|cv-enroll|recommended-content|node/8755|node/8830|node/8351|node/8757|node/8831|cart/(.*)|uc_paypal/(.*)|civicrm/(.*)|admin/(.*)|recommended-content/(.*)|comment/reply/(.*)|node/add/(.*))" ) {
103. return (pass);
104. }
105. // exclude in case of Referer Theme
106. // 排除Referer的一些主题
107. if (req.http.host ~ "domain.org" && req.http.referer ~ "www.christianvolunteering.org|worldvision.christianvolunteering.org|ccda.christianvolunteering.org|www.ccda.org|www.urbanresource.net|mobile.urbanministry.org|www.ministeriourbano.com") {
108. return (pass);
109. }
110. /* Rules to fix Moodle (thanks, gchaix!) */
111. // 修复Moodle规则
112. // Cache Moodle theme files
113. //缓存Moodle主题文件
114. if (req.url ~ "/pix/.*\.gif$") {
115. return (lookup);
116. }
117. // Moodle doesn't like to be cached, passing
118. //Moodle主题不能缓存的就pass
119. if (req.http.Cookie ~ "(MoodleSession|MoodleSessionTest)") {
120. return (pass);
121. }
122. if (req.http.host == "www.domain.edu" && req.url ~ "^/courses") {
123. return (pass);
124. }
125. if (req.url ~ "file.php") {
126. return (pass);
127. }
128. // WPMU themes are not playing well with static file caching
129. //WPMU主题使用静态文件缓存运行的不太好
130. if (req.http.host == "domain.org" && req.url ~ "/blogs/(.*)/wp-content/themes") {
131. return (pass);
132. }
133. /* Rules for static file caching */
134. /* 静态文件缓存规则
135. // static files get served by Lighttpd
136. // 使用Lightted服务静态文件
137. if (req.http.host != "server2.techmission.org" && req.url ~ "\.(gif|jpg|swf|css|js|png|jpg|jpeg|gif|png|tiff|tif|svg|swf|ico|doc|ppt|pps|xls|odc|odb|odf|odg|odi|odp|ods|odt|sxc|sxd|sxi|sxw)$") {
138. // Lighttpd does not require cookies
139. unset req.http.Cookie;
140. unset req.http.Authorization;
141. set req.backend = lighttpd;
142. }
143. // large media files get piped directly to lighttpd, to avoid overfilling cache
144. // 大媒体文件直接使用pipe方式到lightted，避免缓存溢出
145. if (req.url ~ "\.(mp3|mp4|m4a|ogg|mov|avi|wmv)$" && req.url !~ "audio/download") {
146. set req.backend = lighttpd;
147. pipe;
148. }
149. // pipe large media files that come from Drupal, also, but they can't go to lighty
150. // pipe从Drupal过来的大媒体文件，同时不去lighty
151. if (req.url ~ "audio/play" || req.url ~ "audio/download") {
152. pipe;
153. }
154. }
155. sub vcl_hash {
156. if (req.http.Cookie) {
157. set req.hash += req.http.Cookie;
158. }
159. /* Have a separate object cache for mobile site based on User-Agent */
160. /* 基于User-Agent的移动网站有一个单独的对象缓存
161. if (req.http.host == "www.domain.org" && req.http.User-Agent ~ "(iPhone|iPod)") {
162. set req.hash += "mobile";
163. }
164. }
165. sub vcl_fetch {
166. // Grace to allow varnish to serve content if backend is lagged
167. // 如果backend滞后，允许varnish服务内容有一个缓冲期
168. set obj.grace = 5m;
169. // Add line showing what cookie is once stripped by regex in vcl_recv
170. //在vcl_recv中通过regex增加展示cookie一次被剥夺的行
171. set obj.http.X-Stripped-Cookie = req.http.Cookie;
172. set obj.http.X-Request-URL = req.url;
173. /* removing Set-Cookie headers that prevent caching */
174. //删除那些阻止缓存的Set-Cookie头
175. // Don't have cookies on static files (gchaix says may cause loss of session; I haven't observed that)
176. if (req.url ~ "\.(gif|jpg|swf|css|js|png|jpg|jpeg|gif|png|tiff|tif|svg|swf|ico|doc|ppt|pps|xls|odc|odb|odf|odg|odi|odp|ods|odt|sxc|sxd|sxi|sxw)$") {
177. remove obj.http.Set-Cookie;
178. }
179. // Don't set session cookie on ChristianVolunteering.org static files or pages that are same for all users
180. //对于（头）ChristianVolunteering.org的静态文件和网页，对所有用户不设置session cookie
181. if (req.http.host ~ "christianvolunteering.org" &&
182. (req.url ~ "^/$" ||
183. req.url ~ "(searchform|advancedsearch|shorttermmissions|recruitvolunteers|volunteergettingstarted|virtualvolunteer|organizationsearch|abs-bible-outreach|ab*ecutive-volunteers|abs-traveling-engagement-center|churchinstructions|sitemap|city|virtual|organizationlistings|orglistings7407|technology|volunteerlistings|forgotpassword|churchvolunteer|churchvolunteering|servicetrip|region|citysitemap|searchformadv|personalitytest|groupvolunteering|disasterreliefvolunteering|disasterrelief|internships|christiangapyear|about|FAQs|bookrecommendations|contact|pressrelease|training|volunteerstart|volunteerstories|articles)\.jsp$" ||
184. req.url ~ "org/org[0-9]+\.jsp$" ||
185. req.url ~ "org/opp[0-9]+\.jsp$" ||
186. req.url ~ "orglistings[0-9]+\.jsp$" ||
187. req.url ~ "org/[^/]+\.jsp$" ||
188. req.url ~ "volunteer/[^/]+\.jsp$")
189. ) {
190. set obj.http.Set-Cookie = regsuball(req.http.Cookie, "(^|;\s*)(JSESSIONID)=[^;]*", "");
191. // Remove empty set-cookie.
192. if (obj.http.Set-Cookie ~ "^\s*$") {
193. unset obj.http.Set-Cookie;
194. }
195. }
196. /* ttl extensions */
197. /* ttl 扩展 */
198. // If on www.urbanministry.org or static.urbanministry.org, extend TTL by default (pt. 1)
199. //对于www.urbanministry.org或static.urbanministry.org，默认情况下扩展TTL
200. if (req.http.host == "www.domain.org" || req.http.host == "static.domain.org") {
201. set obj.http.X-TTL-Extend = "YES";
202. }
203. // If on cityvision.edu, but not in Moodle, or if on blazinggrace.org, but not in forums, or if on techmission.org, change obj.ttl
204. //如果主机头是cityvision.edu但是不在Moodle中，或者主机头是blazinggrace.org，但不在forums中，或者主机头是techmission.org，更改obj.ttl
205. if ((req.http.host ~ "domain.edu" && req.url !~ "/courses") || (req.http.host ~ "blazinggrace.org" && req.url !~ "/forums")  || (req.http.host ~ "techmission.org")) {
206. set obj.ttl = 7d;
207. set obj.http.X-Extended-TTL = "7d";
208. }
209. if (obj.status == 404) {
210. set obj.ttl = 1s;
211. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
212. }
213. /* debugging of why a page was not cacheable */
214. /* debug为什么页面没有缓存 */
215. if (!obj.cacheable) {
216. set obj.http.X-Cacheable = "NO: Varnish says not cacheable " obj.http.X-Cacheable;
217. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
218. }
219. // exclude umjobs and gospelpedia test sites
220. // 排除umjobs和gospelpedia测试站点
221. if (req.http.host ~ "domain1.org" || req.http.host ~ "domain2.org") {
222. set obj.http.X-Cacheable = "NO: Test domain " obj.http.X-Cacheable;
223. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
224. }
225. if (obj.http.Set-Cookie) {
226. set obj.http.X-Cacheable = "NO: Set-Cookie " obj.http.X-Cacheable;
227. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
228. }
229. if (req.http.Cookie ~ "DRUPAL_UID|SESS") {
230. set obj.http.X-Cacheable = "NO: Got Session " obj.http.X-Cacheable;
231. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
232. }
233. if (obj.http.Cache-Control ~ "private" || obj.http.Cache-Control ~ "no-cache") {
234. set obj.http.X-Cacheable = "NO: Cache-Control set to not cache " obj.http.X-Cacheable;
235. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
236. }
237. if (req.url ~ "cron.php") {
238. set obj.http.X-Cacheable = "NO: Cron job " obj.http.X-Cacheable;
239. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
240. }
241. if (req.http.host ~ "domain.org" && req.url ~ "^/(user/login|user/password|user/register|logout|cart|post-blog|site-feedback|cgi-bin/webscr|redirect-home|cv-enroll|recommended-content|node/8755|node/8830|node/8351|node/8757|node/8831|cart/(.*)|uc_paypal/(.*)|civicrm/(.*)|admin/(.*)|recommended-content/(.*)|comment/reply/(.*)|node/add/(.*))" ) {
242. set obj.http.X-Cacheable = "NO: Drupal un-cacheable path " obj.http.X-Cacheable;
243. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
244. }
245. if (req.http.host ~ "domain.org" && req.http.referer ~ "www.christianvolunteering.org|worldvision.christianvolunteering.org|ccda.christianvolunteering.org|www.ccda.org|www.urbanresource.net|mobile.urbanministry.org|www.ministeriourbano.com") {
246. set obj.http.X-Cacheable = "NO: Referer Theme " obj.http.X-Cacheable;
247. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
248. }
249. if (req.request == "POST") {
250. set obj.http.X-Cacheable = "NO: POST request " obj.http.X-Cacheable;
251. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
252. }
253. if (req.http.Authorization) {
254. set obj.http.X-Cacheable = "NO: HTTP Authentication " obj.http.X-Cacheable;
255. if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
256. }
257. // extend TTL for urbanministry.org objects (but not panels, views, or quicktabs); invalidation thru varnish.module + um_common.module
258. //为urbaministry.org对象扩展TTL（不是面板、视图，或者quicktabs）；经过varnish.module + um_common.module失效
259. if((req.http.host == "www.domain.org" || req.http.host == "static.domain.org") && obj.http.X-TTL-Extend == "YES" && !obj.http.X-Cache-Type) {
260. set obj.ttl = 7d;
261. set obj.http.X-Extended-TTL = "7d";
262. }
263. }
264. sub vcl_deliver {
265. # return (deliver);
266. // add cache hit data
267. // 增加缓存命中数据
268. if (obj.hits > 0) {
269. // if hit add hit count
270. // 如果命中，增加命中数
271. set resp.http.X-Cache = "HIT";
272. set resp.http.X-Cache-Hits = obj.hits;
273. // set resp.http.X-Cache-Served-URL = "SERVED " obj.http.X-Request-URL; // http headers are apparently not accessible in vcl_deliver
274. //在vcl_deliver中http头明显不可访问
275. // set resp.http.X-Cache-TTL = obj.ttl; // string representation not implemented yet (currently on 2.0.5)
276. }
277. else {
278. set resp.http.X-Cache = "MISS";
279. }
280. }
281. /* custom error subroutine - to be a little friendlier to our users */
282. //指定error子程序，对用户有好些
283. sub vcl_error {
284. if(obj.status == 503) {
285. set obj.http.Content-Type = "text/html; charset=utf-8";
286. synthetic {"
287. <?xml version="1.0" encoding="utf-8"?>
288. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
289. "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
290. <html>
291. <head>
292. <title>"} obj.status " " obj.response {"</title>
293. </head>
294. <body>
295. <h1>Error "} obj.status " " obj.response {"</h1>
296. <p>"} obj.response {"</p>
297. <p>Sorry we missed you!</p>
298. <p>We are currently upgrading our websites to serve you better. We should be up again soon.</p>
299. <p>If you still receive this message 30 minutes from now, please email webmaster@techmission.org.</p>
300. <h3>Guru Meditation:</h3>
301. <p>XID: "} req.xid {"</p>
302. <hr>
303. <address>
304. Served by <a href="http://www.varnish-cache.org/">Varnish cache server</a>
305. </address>
306. </body>
307. </html>
308. "};
309. return (deliver);
310. }
311. elsif(obj.status == 403) {
312. set obj.http.Content-Type = "text/html; charset=utf-8";
313. synthetic {"
314. <?xml version="1.0" encoding="utf-8"?>
315. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
316. "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
317. <html>
318. <head>
319. <title>"} obj.status " " obj.response {"</title>
320. </head>
321. <body>
322. <h1>Error "} obj.status " " obj.response {"</h1>
323. <p>"} obj.response {"</p>
324. <h2>TechMission Developer Access Only</h2>
325. <p>This page is only accessible to our staff. Please visit our main websites www.techmission.org,www.urbanministry.org, and " title="www.christianvolunteering.org.
326. " style="color: rgb(2, 122, 198); font-weight: bold; text-decoration: none; ">www.christianvolunteering.org.</p>
327. <!-- (If you should have access to this page, edit the VCL file to grant yourself access (by adding your current IP to the ACL) and then reload the VCL.) -->
328. <h3>Guru Meditation:</h3>
329. <p>XID: "} req.xid {"</p>
330. <hr>
331. <address>
332. Served by <a href="http://www.varnish-cache.org/">Varnish cache server</a>
333. </address>
334. </body>
335. </html>
336. "};
337. return (deliver);
338. }
339. else {
340. set obj.http.Content-Type = "text/html; charset=utf-8";
341. synthetic {"
342. <?xml version="1.0" encoding="utf-8"?>
343. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
344. "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
345. <html>
346. <head>
347. <title>"} obj.status " " obj.response {"</title>
348. </head>
349. <body>
350. <h1>Error "} obj.status " " obj.response {"</h1>
351. <p>"} obj.response {"</p>
352. <h3>Guru Meditation:</h3>
353. <p>XID: "} req.xid {"</p>
354. <hr>
355. <address>
356. Served by <a href="http://www.varnish-cache.org/">Varnish cache server</a>
357. </address>
358. </body>
359. </html>
360. "};
361. return (deliver);
362. }
363. }

在这里感谢 sens杨 同学对配置文档的解释。

下面我们小编特整理的没有前面数字的文件方法大家使用

backend default {
 .host = "127.0.0.1";
 .port = "8008";
 .connect_timeout = 600s;
 .first_byte_timeout = 600s;
 .between_bytes_timeout = 600s;
} 

backend lighttpd {
 .host = "127.0.0.1";
 .port = "81";
 .connect_timeout = 600s;
 .first_byte_timeout = 600s;
 .between_bytes_timeout = 600s;
} 

acl techmission_internal {
 "localhost";
 "127.0.0.1";
}
sub vcl_recv {
 // Allow a grace period for offering "stale" data in case backend lags (http://varnish-cache.org/wiki/VCLExampleGrace)
// 如果backend数据滞后，允许为“过时”数据提供一个宽松期
 set req.grace = 5m;
 // block outside world from our test sites
// 阻止非自己说测试网站（的数据访问）
 if ((req.http.host ~ "www.domain1.org|www.domain2.org") && !(client.ip ~ techmission_internal) && !(req.url ~ "^/ad|^/files")) {
  error 403 "Forbidden";
 }
 if((req.url ~ "/server-status" || req.url ~ "/whm-server-status") && !(client.ip ~ techmission_internal)) {
 error 404 "Not Found";
 }
 // add ping url to test Varnish status
// 增加ping URL测试varnish状态（这个功能使用大部分vcl都没配置，可以增加一个监控状态）
 if (req.request == "GET" && req.url ~ "/varnish-ping") {
 error 200 "OK";
 }
/* Normalize host header to reduce variation in cache */
// 使host头规范化，以减少在cache中变化（这个为什么会说变化呢？）
if (req.http.host == "domain.org" && req.url !~ "^/blogs") {
 set req.http.host = "www.domain.org";
} 

/* Normalize Accept-Encoding to reduce effects of Vary: Accept-Encoding
  (cf. http://varnish-cache.org/wiki/FAQ/Compression)
  Also note that Vary: User-Agent is considered harmful
  (cf. http://www.mail-archive.com/varnish-misc@projects.linpro.no/msg03296.html) */
//规范化Accept-Encoding以减少Vary：Accept-Encoding影响（cf），也要注意Vary: User-Agent认为是有害的 

 if (req.http.Accept-Encoding) {
//if先判断是否可以存在，是为了缩小处理范围？
//看到的其他大部分配置直接就下面了，没有先判断Accept-Encoding是否存在，这点可以再考虑考虑
//现在有req.can_gzip参数了，判断客户端是否接受压缩代码传输
  if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg)$") {
   // Don't compress already-compressed files
   remove req.http.Accept-Encoding;
  }
  elsif (req.http.Accept-Encoding ~ "gzip") {
    set req.http.Accept-Encoding = "gzip";
  }
  elsif (req.http.Accept-Encoding ~ "deflate") {
    set req.http.Accept-Encoding = "deflate";
  }
  else {
   // unknown algorithm
// 不了解运算
   remove req.http.Accept-Encoding;
  }
 } 

 // Remove has_js and Google Analytics __* cookies. Also remove collapsiblock cookies.
//删除has_js和谷歌统计__*的cookies，同时删除collapsiblock cookies
 set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(__[a-z]+|__utma_a2a|has_js|collapsiblock)=[^;]*", "");
 // Remove JSESSIONID cookie from ChristianVolunteering.org static files and pages that are same for all users
//从ChristianVolunteering.org静态文件和网页中删除JSESSIONID cookie，所有的用户是一样（处理）的
  if (req.http.host ~ "christianvolunteering.org" &&
     (req.url ~ "^/$" ||
     req.url ~ "(searchform|advancedsearch|shorttermmissions|recruitvolunteers|volunteergettingstarted|virtualvolunteer|organizationsearch|abs-bible-outreach|ab*ecutive-volunteers|abs-traveling-engagement-center|churchinstructions|sitemap|city|virtual|organizationlistings|orglistings7407|technology|volunteerlistings|forgotpassword|churchvolunteer|churchvolunteering|servicetrip|region|citysitemap|searchformadv|personalitytest|groupvolunteering|disasterreliefvolunteering|disasterrelief|internships|christiangapyear|about|FAQs|bookrecommendations|contact|pressrelease|training|volunteerstart|volunteerstories|articles)\.jsp$" ||
     req.url ~ "org/org[0-9]+\.jsp$" ||
     req.url ~ "org/opp[0-9]+\.jsp$" ||
     req.url ~ "orglistings[0-9]+\.jsp$" ||
     req.url ~ "org/[^/]+\.jsp$" ||
     req.url ~ "volunteer/[^/]+\.jsp$")
    ) {
  set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(JSESSIONID)=[^;]*", "");
 }
 // Remove a ";" prefix, if present.
//如果有”;”前缀，则删除
 set req.http.Cookie = regsub(req.http.Cookie, "^;\s*", "");
 // Remove empty cookies.
// 删除空cookies
 if (req.http.Cookie ~ "^\s*$") {
  unset req.http.Cookie;
 }  

 // exclude umjobs and gospelpedia test sites
// 排除umjos和gospelpedia测试站点
 if (req.http.host ~ "domain1.org" || req.http.host ~ "domain2.org") {
  return (pass);
 } 

 // exclude the cron and supercron pages
// 排除cron和supercron网页
 if (req.url ~ "cron.php") {
  return (pass);
 }
 // exclude dynamic pages (as did Boost)
// 排除动态网页（也是提高（处理））
 if (req.http.host ~ "domain.org" && req.url ~ "^/(user/login|user/password|user/register|logout|cart|post-blog|site-feedback|cgi-bin/webscr|redirect-home|cv-enroll|recommended-content|node/8755|node/8830|node/8351|node/8757|node/8831|cart/(.*)|uc_paypal/(.*)|civicrm/(.*)|admin/(.*)|recommended-content/(.*)|comment/reply/(.*)|node/add/(.*))" ) {
  return (pass);
 } 

 // exclude in case of Referer Theme
// 排除Referer的一些主题
 if (req.http.host ~ "domain.org" && req.http.referer ~ "www.christianvolunteering.org|worldvision.christianvolunteering.org|ccda.christianvolunteering.org|www.ccda.org|www.urbanresource.net|mobile.urbanministry.org|www.ministeriourbano.com") {
  return (pass);
 }
 /* Rules to fix Moodle (thanks, gchaix!) */
// 修复Moodle规则
  // Cache Moodle theme files
//缓存Moodle主题文件
  if (req.url ~ "/pix/.*\.gif$") {
   return (lookup);
  } 

  // Moodle doesn't like to be cached, passing
//Moodle主题不能缓存的就pass
  if (req.http.Cookie ~ "(MoodleSession|MoodleSessionTest)") {
   return (pass);
  }
  if (req.http.host == "www.domain.edu" && req.url ~ "^/courses") {
   return (pass);
  }
  if (req.url ~ "file.php") {
   return (pass);
  } 

  // WPMU themes are not playing well with static file caching
//WPMU主题使用静态文件缓存运行的不太好
  if (req.http.host == "domain.org" && req.url ~ "/blogs/(.*)/wp-content/themes") {
   return (pass);
  }
 /* Rules for static file caching */
 /* 静态文件缓存规则
 // static files get served by Lighttpd
// 使用Lightted服务静态文件
 if (req.http.host != "server2.techmission.org" && req.url ~ "\.(gif|jpg|swf|css|js|png|jpg|jpeg|gif|png|tiff|tif|svg|swf|ico|doc|ppt|pps|xls|odc|odb|odf|odg|odi|odp|ods|odt|sxc|sxd|sxi|sxw)$") {
   // Lighttpd does not require cookies
   unset req.http.Cookie;
   unset req.http.Authorization;
   set req.backend = lighttpd;
 } 

 // large media files get piped directly to lighttpd, to avoid overfilling cache
// 大媒体文件直接使用pipe方式到lightted，避免缓存溢出
 if (req.url ~ "\.(mp3|mp4|m4a|ogg|mov|avi|wmv)$" && req.url !~ "audio/download") {
  set req.backend = lighttpd;
  pipe;
 }
 // pipe large media files that come from Drupal, also, but they can't go to lighty
// pipe从Drupal过来的大媒体文件，同时不去lighty
 if (req.url ~ "audio/play" || req.url ~ "audio/download") {
  pipe;
 } 

}
sub vcl_hash {
 if (req.http.Cookie) {
  set req.hash += req.http.Cookie;
 }
 /* Have a separate object cache for mobile site based on User-Agent */
/* 基于User-Agent的移动网站有一个单独的对象缓存
 if (req.http.host == "www.domain.org" && req.http.User-Agent ~ "(iPhone|iPod)") {
  set req.hash += "mobile";
 }
}
sub vcl_fetch {
 // Grace to allow varnish to serve content if backend is lagged
// 如果backend滞后，允许varnish服务内容有一个缓冲期
 set obj.grace = 5m; 

 // Add line showing what cookie is once stripped by regex in vcl_recv
//在vcl_recv中通过regex增加展示cookie一次被剥夺的行
 set obj.http.X-Stripped-Cookie = req.http.Cookie;
 set obj.http.X-Request-URL = req.url; 

 /* removing Set-Cookie headers that prevent caching */
 //删除那些阻止缓存的Set-Cookie头
 // Don't have cookies on static files (gchaix says may cause loss of session; I haven't observed that)
  if (req.url ~ "\.(gif|jpg|swf|css|js|png|jpg|jpeg|gif|png|tiff|tif|svg|swf|ico|doc|ppt|pps|xls|odc|odb|odf|odg|odi|odp|ods|odt|sxc|sxd|sxi|sxw)$") {
  remove obj.http.Set-Cookie;
 } 

 // Don't set session cookie on ChristianVolunteering.org static files or pages that are same for all users
//对于（头）ChristianVolunteering.org的静态文件和网页，对所有用户不设置session cookie
  if (req.http.host ~ "christianvolunteering.org" &&
     (req.url ~ "^/$" ||
     req.url ~ "(searchform|advancedsearch|shorttermmissions|recruitvolunteers|volunteergettingstarted|virtualvolunteer|organizationsearch|abs-bible-outreach|ab*ecutive-volunteers|abs-traveling-engagement-center|churchinstructions|sitemap|city|virtual|organizationlistings|orglistings7407|technology|volunteerlistings|forgotpassword|churchvolunteer|churchvolunteering|servicetrip|region|citysitemap|searchformadv|personalitytest|groupvolunteering|disasterreliefvolunteering|disasterrelief|internships|christiangapyear|about|FAQs|bookrecommendations|contact|pressrelease|training|volunteerstart|volunteerstories|articles)\.jsp$" ||
     req.url ~ "org/org[0-9]+\.jsp$" ||
     req.url ~ "org/opp[0-9]+\.jsp$" ||
     req.url ~ "orglistings[0-9]+\.jsp$" ||
 req.url ~ "org/[^/]+\.jsp$" ||
     req.url ~ "volunteer/[^/]+\.jsp$")
    ) {
  set obj.http.Set-Cookie = regsuball(req.http.Cookie, "(^|;\s*)(JSESSIONID)=[^;]*", "");
  // Remove empty set-cookie.
  if (obj.http.Set-Cookie ~ "^\s*$") {
   unset obj.http.Set-Cookie;
  }
 } 

/* ttl extensions */
/* ttl 扩展 */
// If on www.urbanministry.org or static.urbanministry.org, extend TTL by default (pt. 1)
//对于www.urbanministry.org或static.urbanministry.org，默认情况下扩展TTL
 if (req.http.host == "www.domain.org" || req.http.host == "static.domain.org") {
  set obj.http.X-TTL-Extend = "YES";
 } 

 // If on cityvision.edu, but not in Moodle, or if on blazinggrace.org, but not in forums, or if on techmission.org, change obj.ttl
//如果主机头是cityvision.edu但是不在Moodle中，或者主机头是blazinggrace.org，但不在forums中，或者主机头是techmission.org，更改obj.ttl
 if ((req.http.host ~ "domain.edu" && req.url !~ "/courses") || (req.http.host ~ "blazinggrace.org" && req.url !~ "/forums") || (req.http.host ~ "techmission.org")) {
  set obj.ttl = 7d;
  set obj.http.X-Extended-TTL = "7d";
} 

if (obj.status == 404) {
  set obj.ttl = 1s;
if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
}  

 /* debugging of why a page was not cacheable */
/* debug为什么页面没有缓存 */
 if (!obj.cacheable) {
  set obj.http.X-Cacheable = "NO: Varnish says not cacheable " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 // exclude umjobs and gospelpedia test sites
// 排除umjobs和gospelpedia测试站点
 if (req.http.host ~ "domain1.org" || req.http.host ~ "domain2.org") {
  set obj.http.X-Cacheable = "NO: Test domain " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (obj.http.Set-Cookie) {
  set obj.http.X-Cacheable = "NO: Set-Cookie " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (req.http.Cookie ~ "DRUPAL_UID|SESS") {
  set obj.http.X-Cacheable = "NO: Got Session " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (obj.http.Cache-Control ~ "private" || obj.http.Cache-Control ~ "no-cache") {
  set obj.http.X-Cacheable = "NO: Cache-Control set to not cache " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (req.url ~ "cron.php") {
  set obj.http.X-Cacheable = "NO: Cron job " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (req.http.host ~ "domain.org" && req.url ~ "^/(user/login|user/password|user/register|logout|cart|post-blog|site-feedback|cgi-bin/webscr|redirect-home|cv-enroll|recommended-content|node/8755|node/8830|node/8351|node/8757|node/8831|cart/(.*)|uc_paypal/(.*)|civicrm/(.*)|admin/(.*)|recommended-content/(.*)|comment/reply/(.*)|node/add/(.*))" ) {
  set obj.http.X-Cacheable = "NO: Drupal un-cacheable path " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (req.http.host ~ "domain.org" && req.http.referer ~ "www.christianvolunteering.org|worldvision.christianvolunteering.org|ccda.christianvolunteering.org|www.ccda.org|www.urbanresource.net|mobile.urbanministry.org|www.ministeriourbano.com") {
  set obj.http.X-Cacheable = "NO: Referer Theme " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (req.request == "POST") {
  set obj.http.X-Cacheable = "NO: POST request " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 if (req.http.Authorization) {
  set obj.http.X-Cacheable = "NO: HTTP Authentication " obj.http.X-Cacheable;
  if (obj.http.X-TTL-Extend) { unset obj.http.X-TTL-Extend; }
 } 

 // extend TTL for urbanministry.org objects (but not panels, views, or quicktabs); invalidation thru varnish.module + um_common.module
//为urbaministry.org对象扩展TTL（不是面板、视图，或者quicktabs）；经过varnish.module + um_common.module失效
 if((req.http.host == "www.domain.org" || req.http.host == "static.domain.org") && obj.http.X-TTL-Extend == "YES" && !obj.http.X-Cache-Type) {
  set obj.ttl = 7d;
  set obj.http.X-Extended-TTL = "7d";
 } 

}
sub vcl_deliver {
# return (deliver);
 // add cache hit data
// 增加缓存命中数据
 if (obj.hits > 0) {
  // if hit add hit count
// 如果命中，增加命中数
  set resp.http.X-Cache = "HIT";
  set resp.http.X-Cache-Hits = obj.hits;
  // set resp.http.X-Cache-Served-URL = "SERVED " obj.http.X-Request-URL; // http headers are apparently not accessible in vcl_deliver
//在vcl_deliver中http头明显不可访问
  // set resp.http.X-Cache-TTL = obj.ttl; // string representation not implemented yet (currently on 2.0.5)
 }
 else {
  set resp.http.X-Cache = "MISS";
 }
}
/* custom error subroutine - to be a little friendlier to our users */
//指定error子程序，对用户有好些
sub vcl_error {
if(obj.status == 503) {
  set obj.http.Content-Type = "text/html; charset=utf-8";
  synthetic {"
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
 <head>
  <title>"} obj.status " " obj.response {"</title>
</head>
 <body>
  <h1>Error "} obj.status " " obj.response {"</h1>
  <p>"} obj.response {"</p>
<p>Sorry we missed you!</p>
<p>We are currently upgrading our websites to serve you better. We should be up again soon.</p>
<p>If you still receive this message 30 minutes from now, please email webmaster@techmission.org.</p>
  <h3>Guru Meditation:</h3>
  <p>XID: "} req.xid {"</p>
  <hr>
  <address>
    Served by <a href="http://www.varnish-cache.org/">Varnish cache server</a>
  </address>
 </body>
</html>
"};
  return (deliver);
}
elsif(obj.status == 403) {
  set obj.http.Content-Type = "text/html; charset=utf-8";
  synthetic {"
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
 <head>
  <title>"} obj.status " " obj.response {"</title>
</head>
 <body>
  <h1>Error "} obj.status " " obj.response {"</h1>
  <p>"} obj.response {"</p>
<h2>TechMission Developer Access Only</h2>
<p>This page is only accessible to our staff. Please visit our main websites www.techmission.org,www.urbanministry.org, and " title="www.christianvolunteering.org.
" style="color: rgb(2, 122, 198); font-weight: bold; text-decoration: none; ">www.christianvolunteering.org.</p>
<!-- (If you should have access to this page, edit the VCL file to grant yourself access (by adding your current IP to the ACL) and then reload the VCL.) -->
  <h3>Guru Meditation:</h3>
  <p>XID: "} req.xid {"</p>
  <hr>
  <address>
    Served by <a href="http://www.varnish-cache.org/">Varnish cache server</a>
  </address>
 </body>
</html>
"};
  return (deliver);
}
else {
  set obj.http.Content-Type = "text/html; charset=utf-8";
  synthetic {"
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
 <head>
  <title>"} obj.status " " obj.response {"</title>
</head>
 <body>
  <h1>Error "} obj.status " " obj.response {"</h1>
  <p>"} obj.response {"</p>
  <h3>Guru Meditation:</h3>
  <p>XID: "} req.xid {"</p>
  <hr>
  <address>
    Served by <a href="http://www.varnish-cache.org/">Varnish cache server</a>
  </address>
 </body>
</html>
"};
  return (deliver);
}
}