[KNOX-643] Add the ability to gather and expose metrics in the gateway

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0
• Fix Version/s: 0.11.0
• Component/s: Server
• Assignee: Sumit Gupta
• Reporter: Sumit Gupta
• Created: 22/Dec/15 15:18
• Updated: 28/Mar/19 14:17
• Resolved: 10/Nov/16 21:26

Description

The goal would be to capture various request/response metrics in the gateway and expose them via JMX and/or REST.

Some of the requests on the dev mailing list are:

• Capture TPS both at the service level as well as aggregate for the server instance.
• Byte transfer counts per service and aggregate
• Unsuccessful login
• Successful login but overall return was HTTP 500 which indicates failure
  on the cluster side. An example would be users connecting to Knox with
  valid AD user/pass but which were not authorized in the cluster. This can
  happen when the cluster is in secure mode but a service like Centrify has
  not allowed the user into the cluster's zone.
• Unsuccessful AD lookup by Knox - user doesn't exist.
• Connection counts that used and didn't use an auth cookie and resulted in
  an AD lookup
• Current open connections
• Capability to reset the aggregate counters while Knox is running.
• Ability to hook into Ambari's Metric collection framework.

Issue Links

• breaks: KNOX-784 java.lang.IllegalArgumentException: A metric named org.apache.http.conn.HttpClientConnectionManager.available-connections already exists
• breaks: KNOX-921 Httpclient max connections are always set to default values
• is related to: KNOX-782 Add aggregate metrics at the topology and server level
• is related to: KNOX-783 Add REST API for getting metrics from Knox
• is related to: KNOX-781 Add a metrics reporter for Ambari Metrics
• is related to: KNOX-1618 Add dropwizard metrics-jvm support
• is related to: KNOX-940 Support REST access exposing metrics