cubby-app

The cubby app provides a centralized caching service for the CMR. Most caching in the CMR should be done in each application in separate in-memory cache. Sometimes a single central cache will be needed. The cubby application provides that capability. Cubby data is stored in an Elasticsearch index.

Managing Elasticsearch Indexes

During initial deployment the index in Elasticsearch needs to be created. During subsequent deployments if any of the mappings are changed they need to be updated in Elasticsearch. If you are running Cubby locally in a REPL then this is handled for you. In other environments this handled through the main method in cmr.db. One command will detect if the indexes exist or not. If they do not exist they will be created. If they exist the mappings will be updated.

CMR_ELASTIC_HOST=localhost CMR_ELASTIC_PORT=9210 java -cp target/cmr-cubby-app-0.1.0-SNAPSHOT-standalone.jar cmr.db migrate

API

Overview

• /keys
  • GET - fetch all keys.
  • DELETE - Deletes all cached values
  • /:key
    • GET - Fetch value associated with a key
    • PUT - Set a value associated with a key
    • DELETE - remove a key
• /reset
  • POST - Recreates indexes dropping all data.
• /db-migrate
  • POST - Run database migration
• /health
  • GET - Returns the health of the application
• /caches
  • GET - Returns a list of the in memory caches.
  • /:cache-name
    • GET - Gets the keys of the given cache
    • /:cache-key
      • GET - Fetches value of item cached with this key.
  • /clear-caches
    • POST - Clear caches

Set Value

Associates a value with a key

curl -i -XPUT -H "Content-Type: text" http://localhost:3007/keys/my-key-name -d 'save this value'

Get Value

Retrieves a value associated with a key.

curl -i http://localhost:3007/keys/my-key-name
HTTP/1.1 200 OK

save this value

Get All Keys

Gets a list of all the keys that have been saved as a JSON array.

curl -i http://localhost:3007/keys
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8

["my-key-name"]

Delete All Keys

Deletes all the cached keys.

curl -i -XDELETE http://localhost:3007/keys

Admin API

Reset

Drops and recreates the indexes that save cubby data.

curl -XPOST http://localhost:3007/reset

Querying caches

Endpoints are provided for querying the contents of the various in memory caches used by the application. The following curl will return the list of caches:

curl -i http://localhost:3007/caches

The following curl will return the keys for a specific cache:

curl -i http://localhost:3007/caches/cache-name

This curl will return the value for a specific key in the named cache:

curl -i http://localhost:3007/caches/cache-name/cache-key

Run database migration

Update elasticsearch mappings to the latest version:

curl -v -XPOST -H "Echo-Token: XXXX" http://localhost:3007/db-migrate

Check application health

This will report the current health of the application. It checks all resources and services used by the application and reports their healthes in the response body in JSON format. For resources, the report includes an "ok?" status and a "problem" field if the resource is not OK. For services, the report includes an overall "ok?" status for the service and health reports for each of its dependencies. It returns HTTP status code 200 when the application is healthy, which means all its interfacing resources and services are healthy; or HTTP status code 503 when one of the resources or services is not healthy. It also takes pretty parameter for pretty printing the response.

curl -i -XGET "http://localhost:3007/health?pretty=true"

Example healthy response body:

{
  "elastic_search" : {
    "ok?" : true
  },
  "echo" : {
    "ok?" : true
  }
}

Example un-healthy response body:

{
  "elastic_search" : {
    "ok?" : false,
    "problem" : {
      "status" : "Inaccessible",
      "problem" : "Unable to get elasticsearch cluster health, caught exception: Connection refused"
    }
  },
  "echo" : {
    "ok?" : true
  }
}

License

Copyright © 2015 NASA