-
-
Notifications
You must be signed in to change notification settings - Fork 578
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Use Caffeine as DataNucleus L2 cache
Users continue to run into situations where the DataNucleus L2 cache grows to excessive sizes, eventually causing the application to become unresponsive, or crash due to OOM. The default, `Map`-based L2 cache of DataNucleus does not support time- or size-based expiration of entries. Users are thus unable to limit the impact of L2 caching in their environment. Disabling the L2 cache entirely is possible, but because the default L2 caches don't expose hit/miss metrics, we've been blind to the impact of disabling it so far. This change switches the default L2 cache implementation to one backed by Caffeine (https://github.com/ben-manes/caffeine). This cache supports time and size expiry policies, and is capable of exposing more detailed metrics. The example Grafana dashboard was updated to include a widget for the newly available metrics. This should make it easier for users to determine whether they can safely disable L2 caching altogether (i.e. high miss-rates, low hit-rates), and monitor the effectiveness or their configured expiry policies. It should also help us to determine if we can safely turn off L2 caching per default, to avoid such problematic situations for users entirely. Signed-off-by: nscuro <[email protected]>
- Loading branch information
Showing
5 changed files
with
341 additions
and
15 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
105 changes: 105 additions & 0 deletions
105
src/main/java/org/dependencytrack/observability/MeterRegistryCustomizer.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,105 @@ | ||
| /* | ||
| * This file is part of Dependency-Track. | ||
| * | ||
| * Licensed under the Apache License, Version 2.0 (the "License"); | ||
| * you may not use this file except in compliance with the License. | ||
| * You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| * | ||
| * SPDX-License-Identifier: Apache-2.0 | ||
| * Copyright (c) OWASP Foundation. All Rights Reserved. | ||
| */ | ||
| package org.dependencytrack.observability; | ||
|
|
||
| import alpine.common.logging.Logger; | ||
| import alpine.server.persistence.PersistenceManagerFactory; | ||
| import io.github.nscuro.datanucleus.cache.caffeine.CaffeineLevel2Cache; | ||
| import io.micrometer.core.instrument.MeterRegistry; | ||
| import io.micrometer.core.instrument.binder.cache.CaffeineCacheMetrics; | ||
| import org.datanucleus.api.jdo.JDODataStoreCache; | ||
| import org.datanucleus.api.jdo.JDOPersistenceManagerFactory; | ||
| import org.datanucleus.cache.Level2Cache; | ||
|
|
||
| import javax.jdo.PersistenceManager; | ||
| import java.util.concurrent.TimeUnit; | ||
|
|
||
| import static org.datanucleus.PropertyNames.PROPERTY_CACHE_L2_STATISTICS_ENABLED; | ||
| import static org.datanucleus.PropertyNames.PROPERTY_CACHE_L2_TYPE; | ||
|
|
||
| public class MeterRegistryCustomizer implements alpine.common.metrics.MeterRegistryCustomizer { | ||
|
|
||
| private static final Logger LOGGER = Logger.getLogger(MeterRegistryCustomizer.class); | ||
|
|
||
| @Override | ||
| public void accept(final MeterRegistry meterRegistry) { | ||
| maybeRegisterCaffeineLevel2CacheMetrics(meterRegistry); | ||
| } | ||
|
|
||
| /** | ||
| * Register Caffeine-specific metrics for the DataNucleus L2 cache, if and only if | ||
| * Caffeine is configured as L2 cache via {@code datanucleus.cache.level2.type}. | ||
| * <p> | ||
| * DataNucleus' {@link Level2Cache} doesn't expose any more statistics than the size, | ||
| * but we would like to monitor hit, miss, and invalidation metrics. | ||
| */ | ||
| @SuppressWarnings("BusyWait") | ||
| private void maybeRegisterCaffeineLevel2CacheMetrics(final MeterRegistry meterRegistry) { | ||
| // The customizer executes before the persistence context is created. | ||
| // Use a separate thread to wait for the persistence context to become available, | ||
| // and register cache metrics once it is. | ||
| // | ||
| // To prevent the thread from waiting forever (should not happen), | ||
| // cap the max wait duration at 15 seconds. | ||
| final long timeoutMs = TimeUnit.SECONDS.toMillis(15); | ||
|
|
||
| final var thread = new Thread(() -> { | ||
| final long startTimeMs = System.currentTimeMillis(); | ||
|
|
||
| while ((System.currentTimeMillis() - startTimeMs) < timeoutMs) { | ||
| try (final PersistenceManager pm = PersistenceManagerFactory.createPersistenceManager()) { | ||
| final var pmf = (JDOPersistenceManagerFactory) pm.getPersistenceManagerFactory(); | ||
| if (!"caffeine".equals(pmf.getProperties().get(PROPERTY_CACHE_L2_TYPE))) { | ||
| LOGGER.debug("Not registering Caffeine L2 cache metrics, because %s is not \"caffeine\"" | ||
| .formatted(PROPERTY_CACHE_L2_TYPE)); | ||
| return; | ||
| } | ||
| if (!Boolean.TRUE.equals(pmf.getProperties().get(PROPERTY_CACHE_L2_STATISTICS_ENABLED))) { | ||
| LOGGER.debug("Not registering Caffeine L2 cache metrics, because %s is not enabled" | ||
| .formatted(PROPERTY_CACHE_L2_STATISTICS_ENABLED)); | ||
| return; | ||
| } | ||
|
|
||
| final var dataStoreCache = (JDODataStoreCache) pmf.getDataStoreCache(); | ||
| if (dataStoreCache.getLevel2Cache() instanceof final CaffeineLevel2Cache level2Cache) { | ||
| new CaffeineCacheMetrics<>( | ||
| level2Cache.getCaffeineCache(), | ||
| /* cacheName */ "datanucleus_second_level", | ||
| /* tags */ null) | ||
| .bindTo(meterRegistry); | ||
| LOGGER.debug("Registered Caffeine L2 cache metrics"); | ||
| } | ||
|
|
||
| break; | ||
| } catch (IllegalStateException e) { | ||
| // Persistence context not created yet. | ||
| } | ||
|
|
||
| try { | ||
| Thread.sleep(500); | ||
| } catch (InterruptedException e) { | ||
| Thread.currentThread().interrupt(); | ||
| throw new IllegalStateException("Thread was interrupted while sleeping", e); | ||
| } | ||
| } | ||
| }); | ||
| thread.start(); | ||
| } | ||
|
|
||
| } |
1 change: 1 addition & 0 deletions
1
src/main/resources/META-INF/services/alpine.common.metrics.MeterRegistryCustomizer
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1 @@ | ||
| org.dependencytrack.observability.MeterRegistryCustomizer |
Oops, something went wrong.