From fe386548d22554c558bf0beb1f6d8ebadf210cb9 Mon Sep 17 00:00:00 2001
From: Michael Gibney <michael@michaelgibney.net>
Date: Thu, 14 Sep 2023 12:25:54 -0400
Subject: [PATCH] add ability to explicitly reconcile heap directory size
 account against filesystem

---
 .../solr/handler/admin/CoreAdminHandler.java  | 22 +++++++++++
 .../apache/solr/handler/admin/StatusOp.java   | 37 +++++++++++--------
 .../solr/common/params/CoreAdminParams.java   |  7 ++++
 3 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java b/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
index e080af316bf..ad258b1e2f6 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
@@ -21,6 +21,7 @@
 import static org.apache.solr.security.PermissionNameProvider.Name.CORE_EDIT_PERM;
 import static org.apache.solr.security.PermissionNameProvider.Name.CORE_READ_PERM;
 
+import java.io.Closeable;
 import java.io.File;
 import java.lang.invoke.MethodHandles;
 import java.util.ArrayList;
@@ -116,6 +117,27 @@ public CoreAdminHandler(final CoreContainer coreContainer) {
     this.coreAdminAsyncTracker = new CoreAdminAsyncTracker();
   }
 
+  private static final ThreadLocal<Integer> RECONCILE_THRESHOLD = new ThreadLocal<>();
+
+  private static final Closeable CLEAR_RECONCILE_THRESHOLD = RECONCILE_THRESHOLD::remove;
+
+  public static Closeable setReconcileThreshold(String spec) {
+    if (spec != null && !spec.isEmpty()) {
+      int size = Integer.parseInt(spec);
+      if (size >= 0) {
+        RECONCILE_THRESHOLD.set(size);
+      } else if (size == -1) {
+        // support special value `-1` to effectively just print log messages
+        RECONCILE_THRESHOLD.set(Integer.MAX_VALUE);
+      }
+    }
+    return CLEAR_RECONCILE_THRESHOLD;
+  }
+
+  public static Integer getReconcileThreshold() {
+    return RECONCILE_THRESHOLD.get();
+  }
+
   @Override
   public final void init(NamedList<?> args) {
     throw new SolrException(
diff --git a/solr/core/src/java/org/apache/solr/handler/admin/StatusOp.java b/solr/core/src/java/org/apache/solr/handler/admin/StatusOp.java
index c42e7c43c2d..4978201b613 100644
--- a/solr/core/src/java/org/apache/solr/handler/admin/StatusOp.java
+++ b/solr/core/src/java/org/apache/solr/handler/admin/StatusOp.java
@@ -17,6 +17,7 @@
 
 package org.apache.solr.handler.admin;
 
+import java.io.Closeable;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -29,11 +30,13 @@
 
 class StatusOp implements CoreAdminHandler.CoreAdminOp {
   @Override
+  @SuppressWarnings("try")
   public void execute(CoreAdminHandler.CallInfo it) throws Exception {
     SolrParams params = it.req.getParams();
 
     String cname = params.get(CoreAdminParams.CORE);
     String indexInfo = params.get(CoreAdminParams.INDEX_INFO);
+    String reconcile = params.get(CoreAdminParams.RECONCILE_THRESHOLD);
     boolean isIndexInfoNeeded = Boolean.parseBoolean(null == indexInfo ? "true" : indexInfo);
     NamedList<Object> status = new SimpleOrderedMap<>();
     Map<String, Exception> failures = new HashMap<>();
@@ -41,24 +44,26 @@ public void execute(CoreAdminHandler.CallInfo it) throws Exception {
         it.handler.coreContainer.getCoreInitFailures().entrySet()) {
       failures.put(failure.getKey(), failure.getValue().exception);
     }
-    if (cname == null) {
-      List<String> nameList = it.handler.coreContainer.getAllCoreNames();
-      nameList.sort(null);
-      for (String name : nameList) {
+    try (Closeable c = CoreAdminHandler.setReconcileThreshold(reconcile)) {
+      if (cname == null) {
+        List<String> nameList = it.handler.coreContainer.getAllCoreNames();
+        nameList.sort(null);
+        for (String name : nameList) {
+          status.add(
+              name,
+              CoreAdminOperation.getCoreStatus(it.handler.coreContainer, name, isIndexInfoNeeded));
+        }
+        it.rsp.add("initFailures", failures);
+      } else {
+        failures =
+            failures.containsKey(cname)
+                ? Collections.singletonMap(cname, failures.get(cname))
+                : Collections.<String, Exception>emptyMap();
+        it.rsp.add("initFailures", failures);
         status.add(
-            name,
-            CoreAdminOperation.getCoreStatus(it.handler.coreContainer, name, isIndexInfoNeeded));
+            cname,
+            CoreAdminOperation.getCoreStatus(it.handler.coreContainer, cname, isIndexInfoNeeded));
       }
-      it.rsp.add("initFailures", failures);
-    } else {
-      failures =
-          failures.containsKey(cname)
-              ? Collections.singletonMap(cname, failures.get(cname))
-              : Collections.<String, Exception>emptyMap();
-      it.rsp.add("initFailures", failures);
-      status.add(
-          cname,
-          CoreAdminOperation.getCoreStatus(it.handler.coreContainer, cname, isIndexInfoNeeded));
     }
     it.rsp.add("status", status);
   }
diff --git a/solr/solrj/src/java/org/apache/solr/common/params/CoreAdminParams.java b/solr/solrj/src/java/org/apache/solr/common/params/CoreAdminParams.java
index 4d9427f31bb..6ec29c2eb4c 100644
--- a/solr/solrj/src/java/org/apache/solr/common/params/CoreAdminParams.java
+++ b/solr/solrj/src/java/org/apache/solr/common/params/CoreAdminParams.java
@@ -29,6 +29,13 @@ public abstract class CoreAdminParams {
   /** Should the STATUS request include index info * */
   public static final String INDEX_INFO = "indexInfo";
 
+  /**
+   * For STATUS indexInfo requests that track Directory size on-heap, this arg causes the on-heap
+   * size to be reconciled with the filesystem, re-initializing the on-heap tracking if the
+   * difference in bytes is more than the specified amount.
+   */
+  public static final String RECONCILE_THRESHOLD = "reconcileThreshold";
+
   /** If you rename something, what is the new name * */
   public static final String NAME = "name";