Problem - Redis flushed on some stage so while sale or heavy traffic then all server CPU goes 100%.

Result - server stop responding and sites down.

Servers [ Amazon]

    - 2 webserver with 32 GB Ram with 16 core processor
    - 1 cache server with Redis and Solr install
    - amezon CDN used for images
    - Nginx Server + phpfpm
    - Sticky session enabled 
    - RDS database

Magento Application -

 1 . 30,000 products
 2 . 1000 categories
 3 . 4 websites with mulitdomain
 4 . 5 stores - one site have 2 store views

 heavly customized application alots of rewrite

Site load - 400 concurrent user per minute.

| improve this question | | | | |

You have few issues:

  1. bad php code that overloads CPU
  2. slow / not optimized database or few queries.
  3. no Varnish cache - it helps a lot to cool down CPU (even if you have bad code)
  4. servers are too big, you need to use smaller instances with autoscaling. are these two servers load balanced??
  5. do not flush caches under high load!

you need to provide more information like: logs, linux top, and mysql config, mytop, mysqltuner, magento profiler..

| improve this answer | | | | |
  • yes thanks for giving good info, 1 . I observed when increase the higher server the problem start high. Don't know why if you have more info then please let me know. 2 . Its true I used the cache plugin ( Miravit FPC ). It support well and as soon as the traffic higher some how the redis start flushing and its down. do you know the best config for redis for high trafic? – Yogendra - eCommerce Developer Sep 6 '16 at 16:47

I've encountered a similar issue with one of my client where CPU usage was going high during high traffic. From my experience, it seems to be the case of mis-configured server cache.

Apart from this, you should turn on the Profiler, Error Logs & Enable MySQL Slow Queries to confirm if there is some process thats eating up all of your CPU.

Based on the limited information provided by you, I've given the suggestions. If you could share more details, I believe an exact solution may be given.

| improve this answer | | | | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.