CODEWITHSUNDEEP
ruby-on-railsherokuresponseserverlag
Lone Dev
Lone Dev

Reputation: 53

Unexplained high response time on Heroku environment

I'm using a paid Heroku ($35/mo 2x web dyno, $50/mo silver postgresdb) plan for a small internal app with typically 1-2 concurrent users. Database snapshot size is less than 1MB.

App is Rails 4.1. In the last two weeks, there's been a significant performance drop in production env, where Chrome dev tools reports response times like 8s

Typical:

Total ​8.13s
Stalled ​3.643 ms
DNS Lookup ​2.637 ms
Initial connection 235.532 ms
SSL ​133.738 ms
Request sent ​0.546 ms
Waiting (TTFB) ​3.43 s
Content Download ​4.47 s

I'm using Nitrous dev environment and get sub-1s response on dev server with non-precompiled assets (with mirrored db).

I'm a novice programmer and am not clear on how to debug this. Why would I see 800% slower performance than the dev environment on an $85/mo+ Heroku plan? Given my current programming skill level, my app is probably poorly optimized (a few N+1 queries in there...) but how bad can it be when production has 1-2 concurrent users??

Sample from logs if it helps: sample#current_transaction=16478 sample#db_size=18974904bytes sample#tables=28 sample#active-connections=6 sam ple#waiting-connections=0 sample#index-cache-hit-rate=0.99929 sample#table-cache-hit-rate=0.99917 sample#load-avg-1m=0.365 sample#load-avg-5m=0.45 sample#load-avg-15m=0.445 sample#read-iops= 37.587 sample#write-iops=36.7 sample#memory-total=15405616kB sample#memory-free=1409236kB sample#memory-cached=12980840kB sample#memory-postgres=497784kB

Sample from server logs: Completed 200 OK in 78ms (Views: 40.9ms | ActiveRecord: 26.6ms

I'm seeing similar numbers on dev server but the actual visual performance is night and day. The dev responds as you would expect - sub-1s response and render. The production server is 4-5s delay.

I don't think it's related to ISP as suggested because I've actually been traveling and seeing identical performance problems from USA and Europe.

Upvotes: 4

Views: 1944

Answers (1)

atomdev
atomdev

Reputation: 321

Add NewRelic add-on to your app's ecosystem on Heroku and explore what's going on. You can do it from Heroku's dashboard. Choose free plan and you will be provided with 2 weeks trial period of full functionality. After trial period there will be some constraints but anyway it's enough for measuring performance of the small app. Also you can add the Logentries add-on and you will get access to the app's log history via web interface.

Upvotes: 4

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