Realtime Messaging API

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AMI Backend Interface

Goal

The 3Forge Application Monitoring Interface (AMI) provides applications with a simple mechanism for connecting to the 3Forge Relay. 3Forge AMI's consolidated GUI lets users:

  • View the application's health statistics
  • Receive and manage objects though a simple workflow procedure
  • Interact with applications to call routines inside the application

Conventions

  • This document is written from the perspective of the application. "Outbound" is the application sending data, and "inbound" is the Application receiving data.
  • All key words are in a "courier" font.
  • Trailing text is indicated with an ellipses or "...".
  • Special ASCII chars are qualified inside parenthesis.
  • Brackets "[]" indicate optionally supplied data.
  • Examples are in blue.

Overview

This interface is an extension of the 3Forge AMI product. Applications interact with AMI through the relays only, and not the central server nor the front end servers. Each AMI relay, upon startup, establishes a server socket on a well-known configurable port. As each application starts up, it should connect to the server socket of the relay running on its local host. Multiple applications can connect to one relay.

Applications then interact with the relay by sending and receiving "instructions." Instructions are well-defined, atomic, sequential and transactional messages. The first instruction an application sends after connecting must be a login (L) instruction. Following that, applications can send instructions arbitrarily and should listen for incoming instructions. Optionally, applications can send a logout (X) message to initiate a graceful shutdown.

Instruction Format

This protocol is designed to be flexible, compact and human readable. Each instruction must have a type and may contain a sequence number and timestamp. The general format for each message is: TYPE[#SEQNUM][@NOW][|PARAMS...]\n

TYPE: The type of message. Please see following sections for details on each type.

Valid outbound types are:

  • L (login)
  • S (status)
  • S (alert) DEPRECATED
  • O (object)
  • C (command definition)
  • R (response to execute command)
  • D (delete objects)
  • X (exit)
  • H (help)
  • P (pause)
  • D (delete objects)

Valid inbound types are:

  • M (status message)
  • E (execute command)

SEQNUM: (optional) The sequence number of the instruction. If supplied, the first instruction (Login) must have a sequence number of 0, the following message must have a sequence number of 1, and so on. This sequence number will be used when AMI is ack-ing.

NOW: (optional) Current time in milliseconds since the UNIX epoch. This will aid AMI in determining if there is a lag.

PARAMS: (optional) Should be in the format key=value|key2=value|... where entries are pipe (|) delimited and keys are unique.

Notes:

  • Backslashes (\), quotes ("), single quotes ('), (\n,\r,\t,\f,\b)  must be escaped via backslash (\).
  • Unicode within strings must be expressed in 4 digit hex notation such as: \uFFFF
  • Keys must be alphanumeric.
  • All 1 and 2 letter fully upper case keys are reserved.
  • Values that are not numeric must be surrounded in quotes.
  • \n: Each instruction must end with a linefeed (0x0A) or linefeed + carriage (0x0A0x0D).
  • The Syntax determines the parameter type, please note some types have multiple syntaxes:
Type Syntax Example Notes
Integer nnn -234 Whole numbers default to integer
Long nnnL 234L
Double nnn.nnnD 123.123D Decimal if optional
Float nnnF 123F Decimals in a number default to float
nnn.nnn 123.123 Decimals default to float
String "sss" "what" Quotes must be escaped with a backslash (\)
Enum 'sss' 'this' Quotes must be escaped with a backslash (\)
UTC nnnT 1422059533454T Unix epoch
"sss"T(fff) "20140503"T(yyyyMMdd) Uses date format (fff) to parse string (sss) to a utc
JSON "sss"J "{this:\"that\"}J Base 64 UU Encoded
Binary "ssss"U "12fs1323"U Base UUEncoded
Boolean true false true Case sensitive
Null null Null
  • nnn represents 0-9. Numbers must be base 10 and can be signed
  • sss represents alpha numeric
  • fff represents java syntax: http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Outbound Instruction Type

Outbound Instruction Type - Login (L)

Must be the first instruction sent from the application after connecting to the relay. It is used to establish identity and confirm a proper login.

Required fields supplied by application

I: A universally unique string identifying the process. Multiple runs of the same application should have the same ID (I). If an application were to be shut down and restarted, the ID (I) should not change.

Optional parameters supplied by application

Optional parameters are used to provide metrics about the application.

PL: Used to supply a fully qualified java class name to an AMI relay plugin. The class must implement the com.vortex.agent.AmiPlugin interface

O: Used to supply options about the current session. The following options are available and can be used in conjunction by comma delimiting:

  • QUIET - AMI will not send any information back to the client (statuses, etc). Note execute commands (E) will still be send to the client
  • LOG - Force AMI relay  to log data to / from this session (default file = AmiSession.log)
  • UNIX - Force AMI to not send \r on messages
  • WINDOWS - Force AMI to send \r on messages
  • TTY - teletype terminal (for UNIX) is for interactively working with AMI backend

Example

In the below example, we see the optional attributes APP, MEM and STAT are supplied to shed light on the application name, memory used and status. Note that string values are surrounded in quotes. The options are forcing ami to use UNIX formatting (no \r) and force logging at the ami relay.

L|I="12n3f321g19"|APP="SOR"|MEM=12000|STAT="OKAY"|O="UNIX,LOG"

Outbound Instruction Type - Status (S)

Used to update or add metrics about the application.

Optional parameters supplied by application

Optional parameters are used to provide metrics about the status.

Example

In the below example, notice not all metrics need be supplied for a particular status update. Note that a new metric (MSG) was added in the 3rd instruction and the environment status was deleted in the 2nd.

S#1@1374353639915|MEM=13000|env="Prod"

S#2@1374353639925|MEM=15500|STAT="BAD"|env=null

S#3@1374353639955|STAT="OKAY"|MSG="Back to normal" 

Outbound Instruction Type - Object (O)

Used to create facts about an object.

Required fields supplied by application

T: Object type for grouping objects

Optional parameters supplied by application

I: A unique string ID for the object used for updating the object later. Subsequent messages with the same object ID (I) and same running process ID (I) provided in the login (L) will cause an update.

E: Expires on; negative for how far into the future from the time of message receipt in AMI center and positive numbers are exact dates in the future based on Epoch time. Units are milliseconds

A: Associated alert ID (DEPRECATED)

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