Merge 873df1f36d into 4af4c948e9

app/frontend/controllers/address_search_controller.js

@@ -4,10 +4,28 @@ import 'accessible-autocomplete/dist/accessible-autocomplete.min.css'
 
 const options = []
 
+let latestQueryId = 0
+
+const sleep = (ms) => {
+  return new Promise(resolve => setTimeout(resolve, ms))
+}
+
 const fetchOptions = async (query, searchUrl) => {
   if (query.length < 2) {
     throw new Error('Query must be at least 2 characters long.')
   }
+
+  // implement a debounce
+  // this is because this API has periods of high latency if OS Places has an outage
+  // making too many requests can overwhelm the number of threads available on the server
+  // which can in turn cause a site wide outage
+  latestQueryId++
+  const myQueryId = latestQueryId
+  await sleep(500)
+  if (myQueryId !== latestQueryId) {
+    throw new Error('Outdated query, ignoring result.')
+  }
+
   try {
     const response = await fetch(`${searchUrl}?query=${encodeURIComponent(query.trim())}`)
     return await response.json()

app/services/address_client.rb

@@ -35,7 +35,7 @@ private
     client.use_ssl = true
     client.verify_mode = OpenSSL::SSL::VERIFY_PEER
     client.max_retries = 3
-    client.read_timeout = 30 # seconds
+    client.read_timeout = 15 # seconds
     client
   end
 

app/services/uprn_client.rb

@@ -39,7 +39,7 @@ private
     client.use_ssl = true
     client.verify_mode = OpenSSL::SSL::VERIFY_PEER
     client.max_retries = 3
-    client.read_timeout = 30 # seconds
+    client.read_timeout = 20 # seconds
     client
   end