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 ArkoudaSeverDaemon

• 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

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

• 3. “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

var activityMutex : sync string

var idlePeriodStart : atomic real

var seenNotableActivity : atomic bool

proc startAsyncCheckpointTask()

Starts a task for asynchronous checkpointing.

proc serverIdleStart()

Indicates that the server is “idle”. Records “now” as the time when idle-ness started, unless the server is already “idle”, in which case the previous idle-start time is preserved.

proc serverIdleStop()

Indicates that the server is no longer “idle”.

proc serverActivityMark()

proc waitForActivityMutex()

Waits until ‘activityMutex’ is empty; leaves it empty.

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