ServerDaemon

Usage

use ServerDaemon;

or

import ServerDaemon;
enum ServerDaemonType { DEFAULT, INTEGRATION, METRICS, STATUS }
enum constant DEFAULT
enum constant INTEGRATION
enum constant METRICS
enum constant STATUS
const sdLogger = new Logger(logLevel, logChannel)
var serverDaemonTypes = try! getDaemonTypes()
proc getDaemonTypes() throws

  • Retrieves a list of 1..n ServerDaemonType objects generated

  • from the comma-delimited list of ServerDaemonType strings

  • provided in the daemonTypes command-line parameter

proc metricsEnabled()

  • Returns a boolean indicating if Arkouda is configured to generate and

  • make available metrics via a dedicated metrics socket

proc integrationEnabled()

  • Returns a boolean indicating whether Arkouda is configured to

  • register/deregister with an external system such as Kubernetes.

proc multipleServerDaemons()

  • Returns a boolean indicating if there are multiple ServerDaemons

proc register(endpoint: ServiceEndpoint) throws

  • Generates the Kubernetes app name for Arkouda, which varies based

  • upon which pod corresponds to Locale 0.

class ArkoudaServerDaemon

  • The ArkoudaServerDaemon class defines the run and shutdown

  • functions all derived classes must override

var st = new owned SymTab()
var shutdownDaemon = false
var port : int
proc run() throws
proc requestShutdown(user: string) throws

  • Prompts the ArkoudaServerDaemon to initiate a shutdown, triggering

  • a change in state which will cause the derived ArkoudaServerDaemon

  • to (1) exit the daemon loop within the run function and (2) execute

  • the shutdown function.

proc extractRequest(request: string) : RequestMsg throws

  • Converts the incoming request JSON string into RequestMsg object.

proc shutdown() throws

  • Encapsulates logic that is to be invoked once a ArkoduaSeverDaemon

  • has exited the daemon loop.

class DefaultServerDaemon : ArkoudaServerDaemon

  • The DefaultServerDaemon class serves as the default Arkouda server

  • daemon which is run within the arkouda_server driver

var serverToken : string
var arkDirectory : string
var connectUrl : string
var reqCount : int = 0
var repCount : int = 0
var context : ZMQ.Context
var socket : ZMQ.Socket
proc init()
proc getConnectUrl(token: string) throws
proc printServerSplashMessage(token: string, arkDirectory: string) throws
proc createServerConnectionInfo() throws

Creates the serverConnectionInfo file on arkouda_server startup

proc deleteServerConnectionInfo() throws

Deletes the serverConnetionFile on arkouda_server shutdown

proc sendRepMsg(in response: MsgTuple, user: string) : (string, bool) throws

Following processing of incoming message, sends a message back to the client.

proc authenticateUser(token: string) throws

Compares the token submitted by the user with the arkouda_server token. If the tokens do not match, or the user did not submit a token, an ErrorWithMsg is thrown.

Arguments:

token – the submitted token string

override proc requestShutdown(user: string) throws

Sets the shutdownDaemon boolean to true and sends the shutdown command to socket, which stops the arkouda_server listener thread and closes socket.

proc registerServerCommands()

  • Register our server commands in the CommandMap

  • There are 3 general types

    1. Standard, required commands which adhere to the standard Message signature

    1. Specialized, required commands which do not adhere to the standard Message signature

    1. “Optional” modules which are included at compilation time via ServerModules.cfg

proc initArkoudaDirectory() throws
override proc shutdown() throws

  • The overridden shutdown function calls exit(0) if there are multiple

  • ServerDaemons configured for this Arkouda instance.

proc processMetrics(user: string, cmd: string, args: MessageArgs, elapsedTime: real, memUsed: uint) throws
proc processErrorMessageMetrics(user, cmd, errorMsg) throws
proc getErrorName(err)
override proc run() throws
class MetricsServerDaemon : ArkoudaServerDaemon

  • The MetricsServerDaemon provides a separate endpoint for gathering user, request,

  • locale, and server-scoped metrics. The separate port lessens the possibility of

  • metrics requests being blocked by command requests.

var context : ZMQ.Context
var socket : ZMQ.Socket
proc init()
override proc run() throws
class ExternalIntegrationServerDaemon : DefaultServerDaemon

  • The ExternalIntegrationServerDaemon class registers Arkouda with the

  • configured external system and then invokes ArkoudaServerDeamon.run()

override proc run() throws

  • Overridden run function registers the ServerDaemon with an

  • external system and then invokes the parent run function.

override proc shutdown() throws

  • Overridden shutdown function deregisters Arkouda from an external

  • system and then invokes the parent shutdown() function.

class ServerStatusDaemon : ArkoudaServerDaemon

  • The ServerStatusDaemon provides a non-blocking endpoint for retrieving

  • server status via a separate, dedicated port to lessen the chances of

  • blocking incoming status requests with command requests.

var context : ZMQ.Context
var socket : ZMQ.Socket
proc init()
override proc run() throws
proc getServerDaemon(daemonType: ServerDaemonType) : shared ArkoudaServerDaemon throws
proc getServerDaemons() throws