Line data    Source code

       1             : // Copyright (C) 2015 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.server.cache;
      16             : 
      17             : import com.google.common.cache.Cache;
      18             : import com.google.common.cache.CacheStats;
      19             : import com.google.common.collect.ImmutableSet;
      20             : import com.google.gerrit.extensions.registration.DynamicMap;
      21             : import com.google.gerrit.extensions.registration.Extension;
      22             : import com.google.gerrit.extensions.registration.PluginName;
      23             : import com.google.gerrit.metrics.CallbackMetric;
      24             : import com.google.gerrit.metrics.CallbackMetric1;
      25             : import com.google.gerrit.metrics.Description;
      26             : import com.google.gerrit.metrics.Field;
      27             : import com.google.gerrit.metrics.MetricMaker;
      28             : import com.google.gerrit.server.config.GerritServerConfig;
      29             : import com.google.gerrit.server.logging.Metadata;
      30             : import com.google.inject.Inject;
      31             : import com.google.inject.Singleton;
      32             : import java.util.Set;
      33             : import org.eclipse.jgit.lib.Config;
      34             : 
      35             : @Singleton
      36             : public class CacheMetrics {
      37         138 :   private static final Field<String> F_NAME =
      38         138 :       Field.ofString("cache_name", Metadata.Builder::cacheName)
      39         138 :           .description("The name of the cache.")
      40         138 :           .build();
      41             : 
      42             :   @Inject
      43             :   public CacheMetrics(
      44         138 :       MetricMaker metrics, DynamicMap<Cache<?, ?>> cacheMap, @GerritServerConfig Config config) {
      45         138 :     CallbackMetric1<String, Long> memEnt =
      46         138 :         metrics.newCallbackMetric(
      47             :             "caches/memory_cached",
      48             :             Long.class,
      49         138 :             new Description("Memory entries").setGauge().setUnit("entries"),
      50             :             F_NAME);
      51         138 :     CallbackMetric1<String, Double> memHit =
      52         138 :         metrics.newCallbackMetric(
      53             :             "caches/memory_hit_ratio",
      54             :             Double.class,
      55         138 :             new Description("Memory hit ratio").setGauge().setUnit("percent"),
      56             :             F_NAME);
      57         138 :     CallbackMetric1<String, Long> memEvict =
      58         138 :         metrics.newCallbackMetric(
      59             :             "caches/memory_eviction_count",
      60             :             Long.class,
      61         138 :             new Description("Memory eviction count").setGauge().setUnit("evicted entries"),
      62             :             F_NAME);
      63         138 :     CallbackMetric1<String, Long> perDiskEnt =
      64         138 :         metrics.newCallbackMetric(
      65             :             "caches/disk_cached",
      66             :             Long.class,
      67         138 :             new Description("Disk entries used by persistent cache").setGauge().setUnit("entries"),
      68             :             F_NAME);
      69         138 :     CallbackMetric1<String, Double> perDiskHit =
      70         138 :         metrics.newCallbackMetric(
      71             :             "caches/disk_hit_ratio",
      72             :             Double.class,
      73         138 :             new Description("Disk hit ratio for persistent cache").setGauge().setUnit("percent"),
      74             :             F_NAME);
      75             : 
      76         138 :     Set<CallbackMetric<?>> cacheMetrics =
      77         138 :         ImmutableSet.of(memEnt, memHit, memEvict, perDiskEnt, perDiskHit);
      78             : 
      79         138 :     metrics.newTrigger(
      80             :         cacheMetrics,
      81             :         () -> {
      82          15 :           for (Extension<Cache<?, ?>> e : cacheMap) {
      83          15 :             Cache<?, ?> c = e.getProvider().get();
      84          15 :             String name = metricNameOf(e);
      85          15 :             CacheStats cstats = c.stats();
      86          15 :             memEnt.set(name, c.size());
      87          15 :             memHit.set(name, cstats.hitRate() * 100);
      88          15 :             memEvict.set(name, cstats.evictionCount());
      89          15 :             if (c instanceof PersistentCache
      90          15 :                 && config.getBoolean("cache", "enableDiskStatMetrics", false)) {
      91           0 :               PersistentCache.DiskStats d = ((PersistentCache) c).diskStats();
      92           0 :               perDiskEnt.set(name, d.size());
      93           0 :               perDiskHit.set(name, hitRatio(d));
      94             :             }
      95          15 :           }
      96          15 :           cacheMetrics.forEach(CallbackMetric::prune);
      97          15 :         });
      98         138 :   }
      99             : 
     100             :   private static double hitRatio(PersistentCache.DiskStats d) {
     101           0 :     if (d.requestCount() <= 0) {
     102           0 :       return 100;
     103             :     }
     104           0 :     return ((double) d.hitCount() / d.requestCount() * 100);
     105             :   }
     106             : 
     107             :   private static String metricNameOf(Extension<Cache<?, ?>> e) {
     108          15 :     if (PluginName.GERRIT.equals(e.getPluginName())) {
     109          15 :       return e.getExportName();
     110             :     }
     111           0 :     return String.format("plugin/%s/%s", e.getPluginName(), e.getExportName());
     112             :   }
     113             : }