From 44069a75d294fa0ec134449742798bc89e91a9be Mon Sep 17 00:00:00 2001
From: Paras Sud <sud2@illinois.edu>
Date: Sat, 20 Feb 2021 12:51:16 -0800
Subject: [PATCH] Cleanup ReplicationEngine:createThreadPool to avoid
 hardcoding Vcr

---
 .../github/ambry/cloud/VcrReplicationManager.java |  6 ++++++
 .../ambry/replication/ReplicationEngine.java      | 15 ++++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/ambry-cloud/src/main/java/com/github/ambry/cloud/VcrReplicationManager.java b/ambry-cloud/src/main/java/com/github/ambry/cloud/VcrReplicationManager.java
index 79da773511..786ff87903 100644
--- a/ambry-cloud/src/main/java/com/github/ambry/cloud/VcrReplicationManager.java
+++ b/ambry-cloud/src/main/java/com/github/ambry/cloud/VcrReplicationManager.java
@@ -35,6 +35,7 @@
 import com.github.ambry.store.StoreKeyConverterFactory;
 import com.github.ambry.store.StoreKeyFactory;
 import com.github.ambry.utils.SystemTime;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -271,6 +272,11 @@ public long getRemoteReplicaLagFromLocalInBytes(PartitionId partitionId, String
     return -1;
   }
 
+  @Override
+  protected String getReplicaThreadName(String datacenterToReplicateFrom, int threadIndexWithinPool) {
+    return "Vcr" + super.getReplicaThreadName(datacenterToReplicateFrom, threadIndexWithinPool);
+  }
+
   /**
    * Check if replication is allowed from given datacenter.
    * @param datacenterName datacenter name to check.
diff --git a/ambry-replication/src/main/java/com/github/ambry/replication/ReplicationEngine.java b/ambry-replication/src/main/java/com/github/ambry/replication/ReplicationEngine.java
index b86e227a12..120c56f14d 100644
--- a/ambry-replication/src/main/java/com/github/ambry/replication/ReplicationEngine.java
+++ b/ambry-replication/src/main/java/com/github/ambry/replication/ReplicationEngine.java
@@ -343,9 +343,7 @@ private List<ReplicaThread> createThreadPool(String datacenter, int numberOfThre
     ResponseHandler responseHandler = new ResponseHandler(clusterMap);
     for (int i = 0; i < numberOfThreads; i++) {
       boolean replicatingOverSsl = sslEnabledDatacenters.contains(datacenter);
-      String threadIdentity =
-          (startThread ? "Vcr" : "") + "ReplicaThread-" + (dataNodeId.getDatacenterName().equals(datacenter) ? "Intra-"
-              : "Inter-") + i + "-" + datacenter;
+      String threadIdentity = getReplicaThreadName(datacenter, i);
       try {
         StoreKeyConverter threadSpecificKeyConverter = storeKeyConverterFactory.getStoreKeyConverter();
         Transformer threadSpecificTransformer =
@@ -370,6 +368,17 @@ private List<ReplicaThread> createThreadPool(String datacenter, int numberOfThre
     return replicaThreads;
   }
 
+  /**
+   * Chooses a name for a new replica thread.
+   * @param datacenterToReplicateFrom The datacenter that we replicate from in this thread.
+   * @param threadIndexWithinPool The index of the thread within the thread pool.
+   * @return The name of the thread.
+   */
+  protected String getReplicaThreadName(String datacenterToReplicateFrom, int threadIndexWithinPool) {
+    return "ReplicaThread-" + (dataNodeId.getDatacenterName().equals(datacenterToReplicateFrom) ? "Intra-"
+            : "Inter-") + threadIndexWithinPool + "-" + datacenterToReplicateFrom;
+  }
+
   /**
    * Reads the replica tokens from storage, populates the Remote replica info,
    * and re-persists the tokens if they have been reset.