Disable cache cleanup during offline reindex

Offline reindex can potentially suffer from poor performance if
the caches are being pruned, especially when populated caches
are used to speed up reindex. As there is no obvious benefit
from pruning caches during reindex, disable it.

Release-Notes: skip
Change-Id: Ia82f2f03efbbcd6954252721a052b9827faa8194

1 files changed, 25 insertions, 12 deletions

diff --git a/java/com/google/gerrit/server/cache/h2/H2CacheFactory.java b/java/com/google/gerrit/server/cache/h2/H2CacheFactory.java
index 16d62b3cb4..893a42c4a8 100644
--- a/java/com/google/gerrit/server/cache/h2/H2CacheFactory.java
+++ b/java/com/google/gerrit/server/cache/h2/H2CacheFactory.java
@@ -19,6 +19,7 @@ import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
 import com.google.common.flogger.FluentLogger;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.events.LifecycleListener;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.server.cache.CacheBackend;
@@ -29,6 +30,7 @@ import com.google.gerrit.server.cache.h2.H2CacheImpl.SqlStore;
 import com.google.gerrit.server.cache.h2.H2CacheImpl.ValueHolder;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.index.options.IsFirstInsertForEntry;
 import com.google.gerrit.server.logging.LoggingContextAwareExecutorService;
 import com.google.gerrit.server.logging.LoggingContextAwareScheduledExecutorService;
 import com.google.inject.Inject;
@@ -58,32 +60,39 @@ class H2CacheFactory extends PersistentCacheBaseFactory implements LifecycleList
   private final ScheduledExecutorService cleanup;
   private final long h2CacheSize;
   private final boolean h2AutoServer;
+  private final boolean isOfflineReindex;
 
   @Inject
   H2CacheFactory(
       MemoryCacheFactory memCacheFactory,
       @GerritServerConfig Config cfg,
       SitePaths site,
-      DynamicMap<Cache<?, ?>> cacheMap) {
+      DynamicMap<Cache<?, ?>> cacheMap,
+      @Nullable IsFirstInsertForEntry isFirstInsertForEntry) {
     super(memCacheFactory, cfg, site);
     h2CacheSize = cfg.getLong("cache", null, "h2CacheSize", -1);
     h2AutoServer = cfg.getBoolean("cache", null, "h2AutoServer", false);
     caches = new LinkedList<>();
     this.cacheMap = cacheMap;
+    this.isOfflineReindex =
+        isFirstInsertForEntry != null && isFirstInsertForEntry.equals(IsFirstInsertForEntry.YES);
 
     if (diskEnabled) {
       executor =
           new LoggingContextAwareExecutorService(
               Executors.newFixedThreadPool(
                   1, new ThreadFactoryBuilder().setNameFormat("DiskCache-Store-%d").build()));
+
       cleanup =
-          new LoggingContextAwareScheduledExecutorService(
-              Executors.newScheduledThreadPool(
-                  1,
-                  new ThreadFactoryBuilder()
-                      .setNameFormat("DiskCache-Prune-%d")
-                      .setDaemon(true)
-                      .build()));
+          isOfflineReindex
+              ? null
+              : new LoggingContextAwareScheduledExecutorService(
+                  Executors.newScheduledThreadPool(
+                      1,
+                      new ThreadFactoryBuilder()
+                          .setNameFormat("DiskCache-Prune-%d")
+                          .setDaemon(true)
+                          .build()));
     } else {
       executor = null;
       cleanup = null;
@@ -95,9 +104,11 @@ class H2CacheFactory extends PersistentCacheBaseFactory implements LifecycleList
     if (executor != null) {
       for (H2CacheImpl<?, ?> cache : caches) {
         executor.execute(cache::start);
-        @SuppressWarnings("unused")
-        Future<?> possiblyIgnoredError =
-            cleanup.schedule(() -> cache.prune(cleanup), 30, TimeUnit.SECONDS);
+        if (cleanup != null) {
+          @SuppressWarnings("unused")
+          Future<?> possiblyIgnoredError =
+              cleanup.schedule(() -> cache.prune(cleanup), 30, TimeUnit.SECONDS);
+        }
       }
     }
   }
@@ -106,7 +117,9 @@ class H2CacheFactory extends PersistentCacheBaseFactory implements LifecycleList
   public void stop() {
     if (executor != null) {
       try {
-        cleanup.shutdownNow();
+        if (cleanup != null) {
+          cleanup.shutdownNow();
+        }
 
         List<Runnable> pending = executor.shutdownNow();
         if (executor.awaitTermination(15, TimeUnit.MINUTES)) {