From 41c4aca21748667925dcdd16121a0cc68f9a7f36 Mon Sep 17 00:00:00 2001
From: Xiaobing <61892277+klsince@users.noreply.github.com>
Date: Thu, 15 Sep 2022 15:19:59 -0700
Subject: [PATCH] set MDC so that one can route minion task logs to separate
 files cleanly (#9400)

---
 .../taskfactory/TaskFactoryRegistry.java      |  5 +++++
 pinot-tools/src/main/resources/log4j2.xml     | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/pinot-minion/src/main/java/org/apache/pinot/minion/taskfactory/TaskFactoryRegistry.java b/pinot-minion/src/main/java/org/apache/pinot/minion/taskfactory/TaskFactoryRegistry.java
index 42ec64ca2dd4..8d87cc69bcc0 100644
--- a/pinot-minion/src/main/java/org/apache/pinot/minion/taskfactory/TaskFactoryRegistry.java
+++ b/pinot-minion/src/main/java/org/apache/pinot/minion/taskfactory/TaskFactoryRegistry.java
@@ -47,6 +47,7 @@
 import org.apache.pinot.minion.executor.TaskExecutorFactoryRegistry;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 
 
 /**
@@ -85,6 +86,8 @@ public TaskResult run() {
                   .addPhaseTiming(taskType, MinionQueryPhase.TASK_QUEUEING, jobDequeueTimeMs - jobInQueueTimeMs,
                       TimeUnit.MILLISECONDS);
               try {
+                // Set taskId in MDC so that one may config logger to route task logs to separate file.
+                MDC.put("taskId", _taskConfig.getId());
                 _minionMetrics.addValueToGlobalGauge(MinionGauge.NUMBER_OF_TASKS, 1L);
                 return runInternal();
               } finally {
@@ -93,6 +96,8 @@ public TaskResult run() {
                 _minionMetrics
                     .addPhaseTiming(taskType, MinionQueryPhase.TASK_EXECUTION, executionTimeMs, TimeUnit.MILLISECONDS);
                 LOGGER.info("Task: {} completed in: {}ms", _taskConfig.getId(), executionTimeMs);
+                // Clear taskId from MDC to reset it.
+                MDC.remove("taskId");
               }
             }
 
diff --git a/pinot-tools/src/main/resources/log4j2.xml b/pinot-tools/src/main/resources/log4j2.xml
index 66ea8a3d195b..eb5a19af2f32 100644
--- a/pinot-tools/src/main/resources/log4j2.xml
+++ b/pinot-tools/src/main/resources/log4j2.xml
@@ -39,6 +39,25 @@
       </Policies>
       <DefaultRolloverStrategy max="10"/>
     </RollingFile>
+    <Routing name="taskLogs" ignoreExceptions="false">
+      <Routes pattern="${ctx:taskId}">
+        <Route>
+          <RollingFile
+              name="minionTaskLogs-${ctx:taskId}"
+              fileName="${env:LOG_ROOT}/minionTaskLogs-${ctx:taskId:-default}.log"
+              filePattern="${env:LOG_ROOT}/minionTaskLogs-%d{yyyy-MM-dd}-%i.log"
+              immediateFlush="true">
+            <PatternLayout pattern="${env:LOG_PATTERN}"/>
+            <Policies>
+              <SizeBasedTriggeringPolicy size="19500KB"/>
+            </Policies>
+            <DefaultRolloverStrategy max="50"/>
+          </RollingFile>
+        </Route>
+      </Routes>
+      <!-- Created appender TTL -->
+      <IdlePurgePolicy timeToLive="15" timeUnit="minutes"/>
+    </Routing>
   </Appenders>
   <Loggers>
     <Root level="info" additivity="false">