improve sentry reporting, add metrics for hydro

Author: mikesurowiec

lib/hydro.js

@@ -1,5 +1,10 @@
 const crypto = require('crypto')
 const fetch = require('node-fetch')
+const statsd = require('../lib/statsd')
+
+const hydroStats = statsd.childClient({
+  prefix: 'hydro.'
+})
 
 const SCHEMAS = {
   page: 'docs.v0.PageEvent',
@@ -62,7 +67,7 @@ module.exports = class Hydro {
     })
     const token = this.generatePayloadHmac(body)
 
-    return fetch(this.endpoint, {
+    const fn = () => fetch(this.endpoint, {
       method: 'POST',
       body,
       headers: {
@@ -71,5 +76,12 @@ module.exports = class Hydro {
         'X-Hydro-App': 'docs-production'
       }
     })
+
+    const res = await hydroStats.asyncTimer(fn, 'response_time')
+
+    hydroStats.increment(`response_code.${res.statusCode}`, 1)
+    hydroStats.increment('response_code.all', 1)
+
+    return res;
   }
 }

middleware/events.js

@@ -26,15 +26,16 @@ router.post('/', async function postEvents (req, res, next) {
       req.hydro.schemas[fields.type],
       omit(fields, OMIT_FIELDS)
     ).then(async (hydroRes) => {
-      if (!hydroRes.ok) {
-        const err = new Error('Hydro request failed')
+      // Track hydro exceptions in Sentry, but don't track 503s because we can't do anything about service availability
+      if (!hydroRes.ok && hydroRes.status !== 503) {
+        const err = new Error(`Hydro request failed: ${hydroRes.statusText}`)
         err.status = hydroRes.status
         err.path = fields.path
 
         await FailBot.report(err, {
           path: fields.path,
           hydroStatus: hydroRes.status,
-          hydroText: await hydroRes.text()
+          hydroText: hydroRes.statusText
         })
 
         throw err