Revision 58478
Added by Konstantinos Triantafyllou about 4 years ago
| modules/uoa-services-portal/trunk/services/cache/mecache/cache.js | ||
|---|---|---|
| 10 | 10 |
app.use(cors()); |
| 11 | 11 |
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| 12 | 12 |
const register = new prom.Registry(); |
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prom.collectDefaultMetrics({register: register});
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| 13 | 14 |
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| 14 | 15 |
const responses = new prom.Counter({
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| 15 | 16 |
name: 'cache_http_responses_total', |
| 16 | 17 |
help: 'A counter for cache response codes for every API request.', |
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labelNames: ['url', 'code'],
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labelNames: ['scheme', 'target', 'code', 'cache'],
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| 18 | 19 |
registers: [register] |
| 19 | 20 |
}); |
| 20 | 21 |
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const entries = new prom.Counter({
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name: 'cache_used_entries', |
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help: 'A counter to count cache entries', |
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registers: [register] |
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}); |
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| 21 | 28 |
const histogram = new prom.Histogram({
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| 22 | 29 |
name: 'cache_http_request_duration_seconds', |
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help: 'A Histogram for cache. Providing information about API request and load latency in seconds.',
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labelNames: ['url'],
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help: 'A Histogram for cache. Providing information about a cache request and load latency in seconds.',
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labelNames: ['scheme', 'target'],
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| 25 | 32 |
registers: [register], |
| 26 | 33 |
buckets: [0.1, 0.2, 0.5, 1, 2] |
| 27 | 34 |
}); |
| 28 | 35 |
|
| 29 | 36 |
let cache = (duration) => {
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| 30 | 37 |
return (req, res, next) => {
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let key = '__express__' + req.originalUrl || req.url |
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console.log(req.originalUrl || req.url); |
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let key = '__express__' + req.originalUrl || req.url; |
|
| 33 | 39 |
let cachedBody = mcache.get(key); |
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const url = new URL(req.query.url); |
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const target = url.host + '/' + url.pathname.split('/')[1];
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const scheme = url.protocol.replace(':', '');
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const end = histogram.startTimer({scheme: scheme, target: target});
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entries.inc(); |
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| 34 | 45 |
if (cachedBody) {
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res.send(JSON.parse(cachedBody)) |
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res.send(JSON.parse(cachedBody)); |
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responses.inc({scheme: scheme, target: target, code: res.statusCode, cache: 'hit'});
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end(); |
|
| 36 | 49 |
} else {
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end(); |
|
| 37 | 51 |
res.sendResponse = res.send; |
| 38 | 52 |
res.send = (body) => {
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| 39 | 53 |
if (res.statusCode === 200) {
|
| 40 | 54 |
mcache.put(key, body, duration * 1000); |
| 41 | 55 |
} |
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res.sendResponse(body) |
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res.sendResponse(body);
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responses.inc({scheme: scheme, target: target, code: res.statusCode, cache: 'miss'});
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| 44 | 58 |
}; |
| 45 | 59 |
next(); |
| 46 | 60 |
} |
| ... | ... | |
| 57 | 71 |
setTimeout(() => {
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| 58 | 72 |
const url = (req.query) ? req.query.url : null; |
| 59 | 73 |
if (!url) {
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responses.inc({url: null, code: 404});
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| 61 | 74 |
res.status(404).send(getResponse(404, "Not Found ")) //not found |
| 62 | 75 |
} else {
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request.get(url, function (err, response) {
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request.get(encodeURI(url), function (err, response) {
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| 64 | 77 |
// res.header("Access-Control-Allow-Origin", "http://localhost:3000");
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| 65 | 78 |
res.header("Access-Control-Allow-Headers", "Origin, Content-Type, Content-Length");
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| 66 | 79 |
res.header("Access-Control-Allow-Methods", "GET, OPTIONS");
|
| ... | ... | |
| 69 | 82 |
if (!response && err) {
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| 70 | 83 |
res.status(500).send(getResponse(500, "An error occurred for " + url)) |
| 71 | 84 |
} else {
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const end = histogram.startTimer({url: url});
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| 73 | 85 |
res.status(response.status).send(response.body); |
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res.on('finish', function () {
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responses.inc({url: url, code: res.statusCode});
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end(); |
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}); |
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| 78 | 86 |
} |
| 79 | 87 |
}) |
| 80 | 88 |
} |
Also available in: Unified diff
[Cache | Trunk]: Add new metrics, encode url