From dfd1fd069b8d99ff343caeeac544a05d2b3891ec Mon Sep 17 00:00:00 2001
From: tjq <tengjiqi@gmail.com>
Date: Sat, 10 Sep 2022 09:27:57 +0800
Subject: [PATCH] fix: invalid random when JobInfo's maxWorkerCount is a small
 value #449

---
 .../powerjob/server/core/DispatchService.java    | 16 +---------------
 .../remote/worker/WorkerClusterQueryService.java | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/powerjob-server/powerjob-server-core/src/main/java/tech/powerjob/server/core/DispatchService.java b/powerjob-server/powerjob-server-core/src/main/java/tech/powerjob/server/core/DispatchService.java
index 44d36d60..881c5061 100644
--- a/powerjob-server/powerjob-server-core/src/main/java/tech/powerjob/server/core/DispatchService.java
+++ b/powerjob-server/powerjob-server-core/src/main/java/tech/powerjob/server/core/DispatchService.java
@@ -146,9 +146,8 @@ public class DispatchService {
         // 构造任务调度请求
         ServerScheduleJobReq req = constructServerScheduleJobReq(jobInfo, instanceInfo, workerIpList);
 
-
         // 发送请求（不可靠，需要一个后台线程定期轮询状态）
-        WorkerInfo taskTracker = selectTaskTracker(jobInfo, suitableWorkers);
+        WorkerInfo taskTracker = suitableWorkers.get(0);
         String taskTrackerAddress = taskTracker.getAddress();
 
         transportService.tell(Protocol.of(taskTracker.getProtocol()), taskTrackerAddress, req);
@@ -196,17 +195,4 @@ public class DispatchService {
         req.setThreadConcurrency(jobInfo.getConcurrency());
         return req;
     }
-
-    private WorkerInfo selectTaskTracker(JobInfoDO jobInfo, List<WorkerInfo> workerInfos) {
-        DispatchStrategy dispatchStrategy = DispatchStrategy.of(jobInfo.getDispatchStrategy());
-        switch (dispatchStrategy) {
-            case HEALTH_FIRST:
-                return workerInfos.get(0);
-            case RANDOM:
-                return workerInfos.get(ThreadLocalRandom.current().nextInt(workerInfos.size()));
-            default:
-        }
-        // impossible, indian java
-        return workerInfos.get(0);
-    }
 }
diff --git a/powerjob-server/powerjob-server-remote/src/main/java/tech/powerjob/server/remote/worker/WorkerClusterQueryService.java b/powerjob-server/powerjob-server-remote/src/main/java/tech/powerjob/server/remote/worker/WorkerClusterQueryService.java
index da555c0b..04002cb7 100644
--- a/powerjob-server/powerjob-server-remote/src/main/java/tech/powerjob/server/remote/worker/WorkerClusterQueryService.java
+++ b/powerjob-server/powerjob-server-remote/src/main/java/tech/powerjob/server/remote/worker/WorkerClusterQueryService.java
@@ -4,6 +4,7 @@ import com.google.common.collect.Lists;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
+import tech.powerjob.common.enums.DispatchStrategy;
 import tech.powerjob.common.model.DeployedContainerInfo;
 import tech.powerjob.server.common.module.WorkerInfo;
 import tech.powerjob.server.extension.WorkerFilter;
@@ -44,8 +45,17 @@ public class WorkerClusterQueryService {
 
         workers.removeIf(workerInfo -> filterWorker(workerInfo, jobInfo));
 
-        // 按健康度排序
-        workers.sort((o1, o2) -> o2.getSystemMetrics().calculateScore() - o1.getSystemMetrics().calculateScore());
+        DispatchStrategy dispatchStrategy = DispatchStrategy.of(jobInfo.getDispatchStrategy());
+        switch (dispatchStrategy) {
+            case RANDOM:
+                Collections.shuffle(workers);
+                break;
+            case HEALTH_FIRST:
+                workers.sort((o1, o2) -> o2.getSystemMetrics().calculateScore() - o1.getSystemMetrics().calculateScore());
+                break;
+            default:
+                // do nothing
+        }
 
         // 限定集群大小（0代表不限制）
         if (!workers.isEmpty() && jobInfo.getMaxWorkerCount() > 0 && workers.size() > jobInfo.getMaxWorkerCount()) {