Prepare Application Launch Checklist

Introduction

Application Launch checklist is aimed for Devops, Sysops and anyone whois job to make website available and reliable.
The checklist better works for applications which are going to be Live in near feature, but also useful to validate your Devops processes for already running applications.

This checklist is a complied notes from Launch Checklist for Google Cloud Platform. It is mostly targeted on Devops work routines and in a nutshell explain first and necessary Devops steps into launching applications.

Software Architecture Documentation

  • Create an Architectural Summary. Include an overall architectural diagram, a summary of the process flows, detail the service interaction points.
  • List and describe how each service is used. Include use of any 3rd-party APIs.
  • Make it easy accessible and available – the best as wiki pages.

Builds and Releases

  • Document your build and release, configuration, and security management processes.
  • Automate build process. Include automated testing and packaging.
  • Automate release process to provision package between environments. Include rollback functionality.
  • Version your configuration and put it into Configuration Management system like Saltstack, Puppet or Ansible.
  • Simulate build and release failures. Are you able to roll back effectively? Is the process documented?

Disaster recovery

  • Document your routine backup, regular maintenance, and disaster recovery processes.
  • Test your restore process with real data. Determine time required for a full restore and reflect this in the disaster recovery processes.
  • Automate as much as possible.
  • Simulate major outages and test your Disaster Recovery processes
  • Simulate individual services failure to test your incidents recovery process

Monitoring

  • Document and define your system monitoring and alerting processes.
  • Validate that your system monitoring and alerting are sufficient and effective.

Final thoughts

I can not overstate how much final outcome depend on the level of interaction between Developers, Sysops and Devops teams in your organisation.
After application will go live convert it to a training program for every new devop before she will start site support.

Making simple Splunk Nginx dashboard

As a DevOps guy I often do incident analysis, post deployment monitoring and usual logs checks. If you also is using Splunk as me when let me show for you few effective Splunk commands for Nginx logs monitoring.

Extract fileds

To make commands works Nginx log fields have to be extracted into variables.
Where are 2 ways to extract fields:

  1. By default Splunk recognise “access_combined” log format which is default format for Nginx. If it is your case congratulations nothing to do for you!
  2. For custom format of logs you will need to create regular expression. Splunk has built in user interface to extract fields or you can provide regular expression manually.

field_extractor

Website traffic over time and error rate

Unexpected spike in traffic or in error rate are always first thing to look for. Following command build a time chart with response codes. Codes 200/300 is your normal traffic and 400/500 is errors.

timechart count(status) span=1m by status

Website traffic in Splunk

Response time

How do you know if your website running slowly?
For response time I suggest to use 20, 85 and 95 percentile as metrics.
You also can think of average response time metric, but low average response time doesn’t show that website is OK, so I am not using that metric in the query.

timechart perc20(request_time), perc85(request_time), perc95(request_time) span=1m

Response time in Splunk

Traffic by IP

Checking which IPs are most popular is a good way to spot bad guys or misbehaving bot.

top limit=20 clientip

Traffic by IP with splunk

Top of error page

Looking for pages which produce most errors like 500 Internal Server Error or not found pages like 404? Following two queries give you exactly that information.
Top error pages

search status >= 500 | stats count(status) as cnt by uri, status | sort cnt desc

Top 40x error pages

search status >= 400 AND status < 500 | stats count(status) by uri, status | sort cnt desc

TOP nginx error urls with Splunk

Number of timeouts(>30s) per upstream

When you are using Nginx as a proxy server it is very useful to see if any of upstreams are getting timeouts.
Timeouts could be a symptom for: slow application performance, not enough system resources or just upstream server is down.

search upstream_response_time >= 30 | stats count(upstream_response_time) as upstreams by upstream

Splunk get timeout nginx upstreams

Most time consuming upstreams

Most time consuming upstreams showing which of servers are already overloaded by requests and giving you a hint when application needs to be scaled

stats sum(upstream_response_time), count(upstream) by upstream

Most time consuming upstreams

In conclusion

Splunk functions like timechart, stats and top is your best friends for data aggregation. They are like unix tools – the more tools you know the more easier is to build powerful commands.