[solr] branch main updated: SOLR-16689: Improving efficiency of replication process (#1442)

[js...@apache.org]

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jsweeney pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/solr.git


The following commit(s) were added to refs/heads/main by this push:
     new 44c750a29ec SOLR-16689: Improving efficiency of replication process (#1442)
44c750a29ec is described below

commit 44c750a29ecc4ac81562e1e6df501bcbc5ffe39f
Author: Justin Sweeney <ju...@fullstory.com>
AuthorDate: Mon Mar 13 09:17:34 2023 -0600

    SOLR-16689: Improving efficiency of replication process (#1442)
    
    Improving efficiency of replication process by avoiding repeated attempts to replicate empty index and avoiding commit call to leader when replicating to a non-leader replica
---
 solr/CHANGES.txt                                               |  2 ++
 solr/core/src/java/org/apache/solr/cloud/RecoveryStrategy.java |  6 ++++--
 solr/core/src/java/org/apache/solr/handler/IndexFetcher.java   |  2 +-
 solr/solrj/src/java/org/apache/solr/common/cloud/Replica.java  | 10 ++++++++++
 4 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index 8d0bfaeb853..d885dc3c337 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -185,6 +185,8 @@ Optimizations
 
 * SOLR-16487: Replication pooling is optimized based on hard and soft commit settings for a given collection (Justin Sweeney)
 
+* SOLR-16689: Avoiding commits on leader when recovering a non-leader replica and avoiding incorrectly replicating an empty core (Justin Sweeney)
+
 Bug Fixes
 ---------------------
 
diff --git a/solr/core/src/java/org/apache/solr/cloud/RecoveryStrategy.java b/solr/core/src/java/org/apache/solr/cloud/RecoveryStrategy.java
index 565ce004b99..e24b132cf34 100644
--- a/solr/core/src/java/org/apache/solr/cloud/RecoveryStrategy.java
+++ b/solr/core/src/java/org/apache/solr/cloud/RecoveryStrategy.java
@@ -223,8 +223,10 @@ public class RecoveryStrategy implements Runnable, Closeable {
 
     log.info("Attempting to replicate from [{}].", leaderUrl);
 
-    // send commit
-    commitOnLeader(leaderUrl);
+    // send commit if replica could be a leader
+    if (Replica.Type.isLeaderType(replicaType)) {
+      commitOnLeader(leaderUrl);
+    }
 
     // use rep handler directly, so we can do this sync rather than async
     SolrRequestHandler handler = core.getRequestHandler(ReplicationHandler.PATH);
diff --git a/solr/core/src/java/org/apache/solr/handler/IndexFetcher.java b/solr/core/src/java/org/apache/solr/handler/IndexFetcher.java
index 9d61974e859..099bac7ec35 100644
--- a/solr/core/src/java/org/apache/solr/handler/IndexFetcher.java
+++ b/solr/core/src/java/org/apache/solr/handler/IndexFetcher.java
@@ -546,7 +546,7 @@ public class IndexFetcher {
       }
 
       if (latestVersion == 0L) {
-        if (commit.getGeneration() != 0) {
+        if (IndexDeletionPolicyWrapper.getCommitTimestamp(commit) != 0L) {
           // since we won't get the files for an empty index,
           // we just clear ours and commit
           log.info("New index in Leader. Deleting mine...");
diff --git a/solr/solrj/src/java/org/apache/solr/common/cloud/Replica.java b/solr/solrj/src/java/org/apache/solr/common/cloud/Replica.java
index 83155fa48d1..583c4a4e494 100644
--- a/solr/solrj/src/java/org/apache/solr/common/cloud/Replica.java
+++ b/solr/solrj/src/java/org/apache/solr/common/cloud/Replica.java
@@ -129,6 +129,16 @@ public class Replica extends ZkNodeProps implements MapWriter {
     public static Type get(String name) {
       return name == null ? Type.NRT : Type.valueOf(name.toUpperCase(Locale.ROOT));
     }
+
+    /**
+     * Only certain replica types can become leaders
+     *
+     * @param type the type of a replica
+     * @return true if that type is able to be leader, false otherwise
+     */
+    public static boolean isLeaderType(Type type) {
+      return type == null || type == NRT || type == TLOG;
+    }
   }
 
   // immutable