feat(server): autoscaling for application (#1250)

* feat(server): autoscaling for application

* refactor(server): make targetCPUUtilizationPercentage and targetMemoryUtilizationPercentage optional in autoscaling

* refactor(server): reapply hpa immediately when config is changed

* refactor(server): move autoscaling to application resource bundle

* fix(server): add validation for CreateAutoscalingDto

server/package.json

@@ -41,6 +41,7 @@
     "@nestjs/schedule": "^2.1.0",
     "@nestjs/swagger": "^6.1.3",
     "@nestjs/throttler": "^3.1.0",
+    "class-transformer": "^0.5.1",
     "class-validator": "^0.14.0",
     "compression": "^1.7.4",
     "cron-validate": "^1.4.5",

server/src/application/application.controller.ts

@@ -65,6 +65,11 @@ export class ApplicationController {
   @ApiResponseObject(ApplicationWithRelations)
   @Post()
   async create(@Req() req: IRequest, @Body() dto: CreateApplicationDto) {
+    const error = dto.autoscaling.validate()
+    if (error) {
+      return ResponseUtil.error(error)
+    }
+
     const user = req.user
 
     // check regionId exists
@@ -274,6 +279,11 @@ export class ApplicationController {
     @Body() dto: UpdateApplicationBundleDto,
     @Req() req: IRequest,
   ) {
+    const error = dto.autoscaling.validate()
+    if (error) {
+      return ResponseUtil.error(error)
+    }
+
     const app = await this.application.findOne(appid)
     const user = req.user
     const regionId = app.regionId

server/src/application/application.service.ts

@@ -69,6 +69,7 @@ export class ApplicationService {
         {
           appid,
           resource: this.buildBundleResource(dto),
+          autoscaling: this.buildAutoscalingConfig(dto),
           isTrialTier: isTrialTier,
           createdAt: new Date(),
           updatedAt: new Date(),
@@ -292,11 +293,13 @@ export class ApplicationService {
   ) {
     const db = SystemDatabase.db
     const resource = this.buildBundleResource(dto)
+    const autoscaling = this.buildAutoscalingConfig(dto)
+
     const res = await db
       .collection<ApplicationBundle>('ApplicationBundle')
       .findOneAndUpdate(
         { appid },
-        { $set: { resource, updatedAt: new Date(), isTrialTier } },
+        { $set: { resource, autoscaling, updatedAt: new Date(), isTrialTier } },
         {
           projection: {
             'bundle.resource.requestCPU': 0,
@@ -386,4 +389,16 @@ export class ApplicationService {
 
     return resource
   }
+
+  private buildAutoscalingConfig(dto: UpdateApplicationBundleDto) {
+    const autoscaling = {
+      enable: false,
+      minReplicas: 1,
+      maxReplicas: 5,
+      targetCPUUtilizationPercentage: null,
+      targetMemoryUtilizationPercentage: null,
+      ...dto.autoscaling,
+    }
+    return autoscaling
+  }
 }

server/src/application/dto/create-autoscaling.dto.ts

@@ -0,0 +1,70 @@
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger'
+import {
+  IsBoolean,
+  IsInt,
+  IsNotEmpty,
+  IsOptional,
+  Max,
+  Min,
+  ValidateIf,
+} from 'class-validator'
+
+export class CreateAutoscalingDto {
+  @ApiProperty({ default: false })
+  @IsNotEmpty()
+  @IsBoolean()
+  enable: boolean
+
+  @ApiProperty({ default: 1 })
+  @IsNotEmpty()
+  @IsInt()
+  @Min(1)
+  @Max(19)
+  @ValidateIf(({ enable }) => enable)
+  minReplicas: number
+
+  @ApiProperty({ default: 5 })
+  @IsNotEmpty()
+  @IsInt()
+  @Min(2)
+  @Max(20)
+  @ValidateIf(({ enable }) => enable)
+  maxReplicas: number
+
+  @ApiPropertyOptional({ default: 50 })
+  @IsOptional()
+  @IsInt()
+  @Min(0)
+  @Max(100)
+  @ValidateIf(({ enable }) => enable)
+  targetCPUUtilizationPercentage?: number
+
+  @ApiPropertyOptional({ default: 50 })
+  @IsOptional()
+  @IsInt()
+  @Min(0)
+  @Max(100)
+  @ValidateIf(({ enable }) => enable)
+  targetMemoryUtilizationPercentage?: number
+
+  validate() {
+    if (this.enable) {
+      if (this.maxReplicas <= this.minReplicas) {
+        return 'Max replicas must be smaller than min replicas.'
+      }
+      if (
+        !this.targetCPUUtilizationPercentage &&
+        !this.targetMemoryUtilizationPercentage
+      ) {
+        return 'Either targetCPUUtilizationPercentage or targetMemoryUtilizationPercentage must be specified.'
+      }
+      if (
+        this.targetCPUUtilizationPercentage &&
+        this.targetMemoryUtilizationPercentage
+      ) {
+        return 'TargetCPUUtilizationPercentage and TargetMemoryUtilizationPercentage cannot be specified simultaneously.'
+      }
+    }
+    return null
+  }
+}

server/src/application/dto/update-application.dto.ts

@@ -1,6 +1,15 @@
 import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger'
-import { IsIn, IsInt, IsNotEmpty, IsString, Length } from 'class-validator'
+import {
+  IsIn,
+  IsInt,
+  IsNotEmpty,
+  IsString,
+  Length,
+  ValidateNested,
+} from 'class-validator'
 import { ApplicationState } from '../entities/application'
+import { CreateAutoscalingDto } from './create-autoscaling.dto'
+import { Type } from 'class-transformer'
 
 const STATES = [
   ApplicationState.Running,
@@ -64,4 +73,9 @@ export class UpdateApplicationBundleDto {
   @IsNotEmpty()
   @IsInt()
   storageCapacity: number
+
+  @ApiProperty({ type: CreateAutoscalingDto })
+  @ValidateNested()
+  @Type(() => CreateAutoscalingDto)
+  autoscaling: CreateAutoscalingDto
 }

server/src/application/entities/application-bundle.ts

@@ -1,5 +1,6 @@
 import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger'
 import { ObjectId } from 'mongodb'
+import { Autoscaling } from './application-configuration'
 
 export class ApplicationBundleResource {
   @ApiProperty({ example: 500 })
@@ -53,6 +54,9 @@ export class ApplicationBundle {
   @ApiProperty()
   resource: ApplicationBundleResource
 
+  @ApiProperty()
+  autoscaling: Autoscaling
+
   @ApiPropertyOptional()
   isTrialTier?: boolean
 

server/src/application/entities/application-configuration.ts

@@ -9,6 +9,23 @@ export class EnvironmentVariable {
   value: string
 }
 
+export class Autoscaling {
+  @ApiProperty()
+  enable: boolean
+
+  @ApiProperty()
+  minReplicas: number
+
+  @ApiProperty()
+  maxReplicas: number
+
+  @ApiProperty()
+  targetCPUUtilizationPercentage?: number
+
+  @ApiProperty()
+  targetMemoryUtilizationPercentage?: number
+}
+
 export class ApplicationConfiguration {
   @ApiProperty({ type: String })
   _id?: ObjectId