Add api white list and rate limiter for gc

hugegraph-api/pom.xml

@@ -86,7 +86,7 @@
                             </addDefaultSpecificationEntries>
                         </manifest>
                         <manifestEntries>
-                            <Implementation-Version>0.38.0.0</Implementation-Version>
+                            <Implementation-Version>0.39.0.0</Implementation-Version>
                         </manifestEntries>
                     </archive>
                 </configuration>

hugegraph-api/src/main/java/com/baidu/hugegraph/api/API.java

@@ -35,7 +35,7 @@
 import com.baidu.hugegraph.HugeGraph;
 import com.baidu.hugegraph.api.schema.Checkable;
 import com.baidu.hugegraph.core.GraphManager;
-import com.baidu.hugegraph.metric.MetricsUtil;
+import com.baidu.hugegraph.metrics.MetricsUtil;
 import com.baidu.hugegraph.server.RestServer;
 import com.baidu.hugegraph.type.HugeType;
 import com.baidu.hugegraph.util.E;

hugegraph-api/src/main/java/com/baidu/hugegraph/api/filter/LoadDetectFilter.java

@@ -19,38 +19,61 @@
 
 package com.baidu.hugegraph.api.filter;
 
+import java.util.List;
+import java.util.Set;
+
 import javax.inject.Singleton;
 import javax.ws.rs.ServiceUnavailableException;
 import javax.ws.rs.container.ContainerRequestContext;
 import javax.ws.rs.container.ContainerRequestFilter;
 import javax.ws.rs.container.PreMatching;
 import javax.ws.rs.core.Context;
+import javax.ws.rs.core.PathSegment;
 import javax.ws.rs.ext.Provider;
 
 import com.baidu.hugegraph.config.HugeConfig;
 import com.baidu.hugegraph.config.ServerOptions;
 import com.baidu.hugegraph.core.WorkLoad;
 import com.baidu.hugegraph.util.Bytes;
+import com.baidu.hugegraph.util.E;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.util.concurrent.RateLimiter;
 
 @Provider
 @Singleton
 @PreMatching
 public class LoadDetectFilter implements ContainerRequestFilter {
 
+    private static final Set<String> WHITE_API_LIST = ImmutableSet.of(
+            "",
+            "apis",
+            "metrics",
+            "versions"
+    );
+
+    // Call gc every 30+ seconds if memory is low and request frequently
+    private static final RateLimiter GC_RATE_LIMITER =
+                         RateLimiter.create(1.0 / 30);
+
     @Context
     private javax.inject.Provider<HugeConfig> configProvider;
     @Context
     private javax.inject.Provider<WorkLoad> loadProvider;
 
     @Override
     public void filter(ContainerRequestContext context) {
+        if (isWhiteAPI(context)) {
+            return;
+        }
+
         HugeConfig config = this.configProvider.get();
         long minFreeMemory = config.get(ServerOptions.MIN_FREE_MEMORY);
         long allocatedMem = Runtime.getRuntime().totalMemory() -
                             Runtime.getRuntime().freeMemory();
         long presumableFreeMem = (Runtime.getRuntime().maxMemory() -
                                   allocatedMem) / Bytes.MB;
         if (presumableFreeMem < minFreeMemory) {
+            gcIfNeeded();
             throw new ServiceUnavailableException(String.format(
                       "The server available memory %s(MB) is below than " +
                       "threshold %s(MB) and can't process the request, " +
@@ -69,4 +92,18 @@ public void filter(ContainerRequestContext context) {
                       ServerOptions.MAX_WORKER_THREADS.name()));
         }
     }
+
+    private static boolean isWhiteAPI(ContainerRequestContext context) {
+        List<PathSegment> segments = context.getUriInfo().getPathSegments();
+        E.checkArgument(segments.size() > 0, "Invalid request uri '%s'",
+                        context.getUriInfo().getPath());
+        String rootPath = segments.get(0).getPath();
+        return WHITE_API_LIST.contains(rootPath);
+    }
+
+    private static void gcIfNeeded() {
+        if (GC_RATE_LIMITER.tryAcquire(1)) {
+            System.gc();
+        }
+    }
 }

hugegraph-api/src/main/java/com/baidu/hugegraph/api/graph/BatchAPI.java

@@ -29,7 +29,7 @@
 import com.baidu.hugegraph.api.API;
 import com.baidu.hugegraph.config.HugeConfig;
 import com.baidu.hugegraph.config.ServerOptions;
-import com.baidu.hugegraph.metric.MetricsUtil;
+import com.baidu.hugegraph.metrics.MetricsUtil;
 import com.baidu.hugegraph.server.RestServer;
 import com.baidu.hugegraph.util.Log;
 import com.codahale.metrics.Meter;

hugegraph-api/src/main/java/com/baidu/hugegraph/api/GremlinAPI.java → hugegraph-api/src/main/java/com/baidu/hugegraph/api/gremlin/GremlinAPI.java

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-package com.baidu.hugegraph.api;
+package com.baidu.hugegraph.api.gremlin;
 
 import javax.inject.Singleton;
 import javax.ws.rs.Consumes;
@@ -34,11 +34,12 @@
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.UriInfo;
 
+import com.baidu.hugegraph.api.API;
 import com.baidu.hugegraph.api.filter.CompressInterceptor;
 import com.baidu.hugegraph.api.filter.CompressInterceptor.Compress;
 import com.baidu.hugegraph.config.HugeConfig;
 import com.baidu.hugegraph.config.ServerOptions;
-import com.baidu.hugegraph.metric.MetricsUtil;
+import com.baidu.hugegraph.metrics.MetricsUtil;
 import com.codahale.metrics.Histogram;
 import com.codahale.metrics.annotation.Timed;
 

hugegraph-api/src/main/java/com/baidu/hugegraph/api/job/GremlinAPI.java

@@ -50,7 +50,7 @@
 import com.baidu.hugegraph.core.GraphManager;
 import com.baidu.hugegraph.job.Job;
 import com.baidu.hugegraph.job.JobBuilder;
-import com.baidu.hugegraph.metric.MetricsUtil;
+import com.baidu.hugegraph.metrics.MetricsUtil;
 import com.baidu.hugegraph.server.RestServer;
 import com.baidu.hugegraph.traversal.optimize.HugeScriptTraversal;
 import com.baidu.hugegraph.util.E;

hugegraph-api/src/main/java/com/baidu/hugegraph/api/metrics/MetricsAPI.java

@@ -38,9 +38,9 @@
 import com.baidu.hugegraph.backend.store.BackendMetrics;
 import com.baidu.hugegraph.backend.tx.GraphTransaction;
 import com.baidu.hugegraph.core.GraphManager;
-import com.baidu.hugegraph.metric.MetricsModule;
-import com.baidu.hugegraph.metric.ServerReporter;
-import com.baidu.hugegraph.metric.SystemMetrics;
+import com.baidu.hugegraph.metrics.MetricsModule;
+import com.baidu.hugegraph.metrics.ServerReporter;
+import com.baidu.hugegraph.metrics.SystemMetrics;
 import com.baidu.hugegraph.util.InsertionOrderUtil;
 import com.baidu.hugegraph.util.JsonUtil;
 import com.baidu.hugegraph.util.Log;

hugegraph-api/src/main/java/com/baidu/hugegraph/api/GraphsAPI.java → hugegraph-api/src/main/java/com/baidu/hugegraph/api/profile/GraphsAPI.java

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-package com.baidu.hugegraph.api;
+package com.baidu.hugegraph.api.profile;
 
 import java.io.File;
 import java.util.Map;
@@ -40,6 +40,7 @@
 import org.slf4j.Logger;
 
 import com.baidu.hugegraph.HugeGraph;
+import com.baidu.hugegraph.api.API;
 import com.baidu.hugegraph.core.GraphManager;
 import com.baidu.hugegraph.server.RestServer;
 import com.baidu.hugegraph.type.define.GraphMode;