*Microservices:* - You can target a specific service (aka module) directly using the URI scheme <service>.<appid>.appspot.com (or <service>.customdomain.tld). On the development server modules are served from different ports on localhost (eg. 8080 for default, 8081 for the next module).
- In both production and on the development server, you can use dispatch rules <https://cloud.google.com/appengine/docs/python/config/dispatchref> to target requests to a specific service based on the URL pattern. - If using the Cloud Endpoints framework, API requests are sent to /_ah/spi/{path-to-method} (v1 <https://cloud.google.com/appengine/docs/python/endpoints/api_server>) or /_ah/api/{path-to-method} (v2 <https://cloud.google.com/endpoints/docs/frameworks/python/api_server>) which can be targeted for routing different API calls with dispatch rules. There is an Endpoints discovery service, but this does not handle routing requests between services. See also 'How Requests are Routed <https://cloud.google.com/appengine/docs/python/how-requests-are-routed>'. *Endpoints:* - Endpoints is intended as a REST API framework. It's technically possible to use it to communicate between services but there are some limitations <https://cloud.google.com/endpoints/docs/frameworks/python/#basic_frameworks_architecture> such as not being able to call an Endpoints API from a task queue or cron job. - A better alternative to Endpoints for inter-service communication is Cloud Pub/Sub. <https://cloud.google.com/pubsub/docs/> See also 'Accessing backend API versions deployed to non-default modules <https://cloud.google.com/appengine/docs/python/endpoints/test_deploy#accessing_backend_api_versions_deployed_to_non-default_modules> '. *Large response/request:* - Storage services such as Memcache <https://cloud.google.com/appengine/docs/python/memcache/>, Datastore <https://cloud.google.com/appengine/docs/python/datastore/> and Cloud Storage <https://cloud.google.com/storage/docs/> are shared across all services and version in a project. It's not necessary to pass data between services using URL endpoints as each service essentially has a fast path to access the same data on the internal network. Let me know if I've missed anything or if you have further questions. On Monday, November 14, 2016 at 10:47:53 AM UTC-5, Pim Reijersen wrote: > > Using the service (aka module) keyword in app.yaml its possible to create > microservices on app engine. > > The reason of this post is to get a better picture of how to setup an > application existing of microservices on the app engine. The application in > question will receive, store and send a good amount of data. > > > *Microservices* > Microservices communicate with eachother using HTTP requests. How do you > decide where the service can be reached, and how does this translate to the > development environment. > > 1. Discovery service? Minimal sample or link? > 2. Hardcoded location <service>.<app_id>.appspot.com? and modify hosts > file for local development? > > > *Endpoints* > > 1. Is it a common practice to use the Endpoints feature to develop an > API for internal communication between services? > 1. Another solution would be a webapp > 2. Is it a common practice to use the Endpoints feature to develop an > REST API for users which communicates with the services? > 1. Another solution would be a webapp > > > *Large response/request* > Developing an application which receives/stores/distrubutes a large data > set. Pushing and pulling data is done using a REST API. My concern is that > the data travels to multiple services over the network increasing bandwith > usage. Example; > [user] -> REST API Service -> Data Service -> Datastore > > In a monolith application the data gets processed directly. In a > microservice application the data travels from the user to the API Service > and is then send to the Data Service to be processed. > > 1. Give the Data Service an API which is accessible by the user? > 2. Is this an issue on App Engine cost wise? > > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/b0936139-37d2-466c-9e1b-c6ceb9044bc9%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
