Add and remove workers during eco mode

app/modules/prover/lib/blockProver.ts

@@ -48,6 +48,14 @@ export class WorkerFarm {
     return this.theEngine.getNbWorkers()
   }
 
+  reduceNbCores() {
+    return this.theEngine.reduceNbCores()
+  }
+
+  boostCPU(){
+    return this.theEngine.boostCPU()
+  }
+
   changeCPU(cpu:any) {
     return this.theEngine.setConf({ cpu })
   }
@@ -194,13 +202,12 @@ export class BlockProver {
       });
       if (!result) {
         this.logger.info('GIVEN proof-of-work for block#%s with %s leading zeros followed by [0-' + highMark + ']! stop PoW for %s', block.number, nbZeros, this.pair && this.pair.pub.slice(0,6));
-        let selfNbBlockInFrame = await this.server.getBcContext().getIssuerNbBlockInFrame(this.server.PeeringService.selfPubkey)
         if(this.conf.ecoMode === true) {
           let selfNbBlockInFrame = await this.server.getBcContext().getIssuerNbBlockInFrame(this.server.PeeringService.selfPubkey)
           if(selfNbBlockInFrame < 2) {
-            this.changeCPU(1)
-            this.conf.nbCores = this.server.conf.nbCores
-            this.logger.info("Boost number of CPU cores "+this.conf.nbCores+" with only "+selfNbBlockInFrame+" block member in frame")
+            this.boostCPU()
+            this.conf.nbCores = powFarm.nbWorkers
+            this.logger.info("Boost number of CPU cores "+powFarm.nbWorkers+" with only "+selfNbBlockInFrame+" block member in frame")
           }
         }
         throw 'Proof-of-work computation canceled because block received';
@@ -214,14 +221,15 @@ export class BlockProver {
         if(this.conf.ecoMode === true) {
           let selfNbBlockInFrame = await this.server.getBcContext().getIssuerNbBlockInFrame(this.server.PeeringService.selfPubkey)
           if(selfNbBlockInFrame < 2) {
-            this.changeCPU(1)
-            this.conf.nbCores = this.server.conf.nbCores
-            this.logger.info("Boost number of CPU cores "+this.conf.nbCores+" with only "+selfNbBlockInFrame+" block member in frame")
+            this.boostCPU()
+            this.conf.nbCores = powFarm.nbWorkers
+            this.logger.info("Boost number of CPU cores "+powFarm.nbWorkers+" with only "+selfNbBlockInFrame+" block member in frame")
           }
-          else if(this.conf.nbCores*testsPerSecond > ProverConstants.ECO_MODE_MINIMAL_TESTS_PER_SECONDS) {
-            if(this.conf.nbCores > 1) {
-              this.logger.info("Reducing number of CPU cores "+this.conf.nbCores)
-              this.conf.nbCores = this.conf.nbCores -1
+          else if(testsPerSecond > ProverConstants.ECO_MODE_MINIMAL_TESTS_PER_SECONDS) {
+            if(powFarm.nbWorkers > 1) {
+              this.logger.info("Reducing number of CPU cores "+powFarm.nbWorkers)
+              this.reduceNbCores()
+              this.conf.nbCores = powFarm.nbWorkers
             }
             else if(this.conf.cpu > ProverConstants.ECO_MODE_MINIMAL_CPU){
               let cpu:number = this.conf.cpu - 0.1
@@ -235,6 +243,17 @@ export class BlockProver {
     })()
   };
 
+  async reduceNbCores() {
+    const farm = await this.getWorker()
+    return farm.reduceNbCores()
+  }
+
+  async boostCPU() {
+    this.conf.cpu = 1.0
+    const farm = await this.getWorker()
+    return farm.boostCPU()
+  }
+
   async changeCPU(cpu:number) {
     this.conf.cpu = Math.max(0.01, Math.min(1.0, cpu));
     const farm = await this.getWorker()

app/modules/prover/lib/engine.ts

@@ -12,15 +12,12 @@ if(debug) {
 
 export class PowEngine {
 
-  private nbWorkers:number
   private cluster:PowCluster
   readonly id:number
 
   constructor(private conf:ConfDTO, logger:any) {
-
     // We use as much cores as available, but not more than CORES_MAXIMUM_USE_IN_PARALLEL
-    this.nbWorkers = conf.nbCores
-    this.cluster = new PowCluster(this.nbWorkers, logger)
+    this.cluster = new PowCluster(conf.nbCores, logger)
     this.id = this.cluster.clusterId
   }
 
@@ -41,6 +38,14 @@ export class PowEngine {
     return this.cluster.cancelWork()
   }
 
+  reduceNbCores() {
+    return this.cluster.removeSlave()
+  }
+
+  boostCPU() {
+    return this.cluster.boostCPU()
+  }
+
   setConf(value:any) {
     return this.cluster.changeConf(value)
   }

app/modules/prover/lib/powCluster.ts

@@ -35,6 +35,7 @@ export class Master {
   logger:any
   onInfoCallback:any
   workersOnline:Promise<any>[]
+  maxNbCores:number = Math.min(ProverConstants.CORES_MAXIMUM_USE_IN_PARALLEL, require('os').cpus().length)
 
   constructor(private nbCores:number, logger:any) {
     this.clusterId = clusterId++
@@ -65,18 +66,7 @@ export class Master {
     // this.logger.debug(`ENGINE c#${this.clusterId}#${this.slavesMap[worker.id].index}:`, message)
   }
 
-  /*****************
-   * CLUSTER METHODS
-   ****************/
-
-  initCluster() {
-    // Setup master
-    cluster.setupMaster({
-      exec: __filename,
-      execArgv: [] // Do not try to debug forks
-    })
-
-    this.slaves = Array.from({ length: this.nbCores }).map((value, index) => {
+  createSlave(index:number) {
     const nodejsWorker = cluster.fork()
     const worker = new PowWorker(nodejsWorker, message => {
       this.onWorkerMessage(index, message)
@@ -107,6 +97,38 @@ export class Master {
     }
     this.slavesMap[nodejsWorker.id] = slave
     return slave
+  }
+
+  boostCPU() {
+    if(this.nbWorkers < this.maxNbCores) {
+      while(this.nbWorkers < this.maxNbCores) {
+        this.slaves.push(this.createSlave(this.nbWorkers))
+      }
+    }
+    let conf:any = {cpu: 1}
+    this.changeConf(conf)
+  }
+
+  async removeSlave() {
+    let nb_workers = this.nbWorkers
+    await this.slaves[nb_workers-1].worker.kill()
+    this.slaves.pop()
+    this.logger.info('Remove slave number '+ (nb_workers-1))
+  }
+
+  /*****************
+   * CLUSTER METHODS
+   ****************/
+
+  initCluster() {
+    // Setup master
+    cluster.setupMaster({
+      exec: __filename,
+      execArgv: [] // Do not try to debug forks
+    })
+
+    this.slaves = Array.from({ length: this.nbCores }).map((value, index) => {
+      return this.createSlave(index)
     })
 
     this.workersOnline = this.slaves.map((s) => s.online)