diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/executor/EventHandler.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/executor/EventHandler.java
index 7176f5306163..01b9029b3f40 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/executor/EventHandler.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/executor/EventHandler.java
@@ -27,6 +27,7 @@
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 
 /**
  * Abstract base class for all HBase event handlers. Subclasses should implement the
@@ -94,10 +95,15 @@ public EventHandler prepare() throws Exception {
 
   @Override
   public void run() {
+    // assume that this is the top of an execution on a new or reused thread, that we're safe to
+    // blast any existing MDC state.
     try (TraceScope scope = TraceUtil.createTrace(this.getClass().getSimpleName(), parent)) {
+      MDC.put("event_type", eventType.toString());
       process();
     } catch (Throwable t) {
       handleException(t);
+    } finally {
+      MDC.clear();
     }
   }
 
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/AssignRegionHandler.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/AssignRegionHandler.java
index 7f9f95bee687..a9ab6f502a35 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/AssignRegionHandler.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/AssignRegionHandler.java
@@ -38,6 +38,7 @@
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode;
 
@@ -93,6 +94,7 @@ private void cleanUpAndReportFailure(IOException error) throws IOException {
 
   @Override
   public void process() throws IOException {
+    MDC.put("pid", Long.toString(openProcId));
     HRegionServer rs = getServer();
     String encodedName = regionInfo.getEncodedName();
     byte[] encodedNameBytes = regionInfo.getEncodedNameAsBytes();
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/RSProcedureHandler.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/RSProcedureHandler.java
index d4ddebe727d7..d3ecc8a51e22 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/RSProcedureHandler.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/RSProcedureHandler.java
@@ -23,6 +23,7 @@
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 
 /**
  * A event handler for running procedure.
@@ -46,6 +47,7 @@ public RSProcedureHandler(HRegionServer rs, long procId, RSProcedureCallable cal
   public void process() {
     Throwable error = null;
     try {
+      MDC.put("pid", Long.toString(procId));
       callable.call();
     } catch (Throwable t) {
       LOG.error("pid=" + this.procId, t);
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/UnassignRegionHandler.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/UnassignRegionHandler.java
index 33eaf675c6a5..e312df9862d5 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/UnassignRegionHandler.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/handler/UnassignRegionHandler.java
@@ -35,6 +35,7 @@
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode;
 
@@ -78,6 +79,7 @@ private HRegionServer getServer() {
 
   @Override
   public void process() throws IOException {
+    MDC.put("pid", Long.toString(closeProcId));
     HRegionServer rs = getServer();
     byte[] encodedNameBytes = Bytes.toBytes(encodedName);
     Boolean previous = rs.getRegionsInTransitionInRS().putIfAbsent(encodedNameBytes, Boolean.FALSE);