title: Google app engine split traffic to single version
body: <p>Google app engine creates a new version for every deployment and it starts serving through the  new version by stopping the older versions (after gradually migrating all traffic to new version).But sometimes due to high load, traffic splits to the older version which starts serving. How to customise the GAE configuration or app.yaml so that all the traffic should only point to the latest one version whatever may be the load.</p>
  
  <p>app.yaml</p>
  
  <pre><code>service: service-name
  runtime: java
  env: flex
  
  runtime_config:
    jdk: openjdk8
  
  handlers:
    - url: /.*
      script: this field is required, but ignored
  
  manual_scaling:
    instances: 1
  
  resources:
    cpu: 1
    memory_gb: 2
  
  network:
    instance_tag: test
    name: dev
    subnetwork_name: dev-1
    session_affinity: true
  </code></pre>