Github user paul-rogers commented on a diff in the pull request:
https://github.com/apache/drill/pull/928#discussion_r143084915
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/work/foreman/rm/DynamicResourceManager.java
---
@@ -0,0 +1,125 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+package org.apache.drill.exec.work.foreman.rm;
+
+import org.apache.drill.exec.ExecConstants;
+import org.apache.drill.exec.ops.QueryContext;
+import org.apache.drill.exec.server.DrillbitContext;
+import org.apache.drill.exec.server.options.SystemOptionManager;
+import org.apache.drill.exec.work.foreman.Foreman;
+import
org.apache.drill.exec.work.foreman.rm.DistributedQueryQueue.StatusAdapter;
+
+/**
+ * Wrapper around the default and/or distributed resource managers
+ * to allow dynamically enabling and disabling queueing.
+ */
+
+public class DynamicResourceManager implements ResourceManager {
+
+ private static final org.slf4j.Logger logger =
org.slf4j.LoggerFactory.getLogger(DynamicResourceManager.class);
+
+ private final DrillbitContext context;
+ private ResourceManager defaultRm;
+ private ResourceManager queueingRm;
+ private ResourceManager activeRm;
+ public long lastUpdateTime;
+ public int recheckDelayMs = 5000;
+
+ public DynamicResourceManager(final DrillbitContext context) {
+ this.context = context;
+ refreshRM();
+ }
+
+ public synchronized ResourceManager activeRM() {
+ refreshRM();
+ return activeRm;
+ }
+
+ @Override
+ public long memoryPerNode() {
+ return activeRm.memoryPerNode();
+ }
+
+ @Override
+ public int cpusPerNode() {
+ return activeRm.cpusPerNode();
+ }
+
+ @Override
+ public synchronized QueryResourceAllocator
newResourceAllocator(QueryContext queryContext) {
+ refreshRM();
+ return activeRm.newResourceAllocator(queryContext);
+ }
+
+ @Override
+ public synchronized QueryResourceManager newQueryRM(Foreman foreman) {
+ refreshRM();
+ return activeRm.newQueryRM(foreman);
+ }
+
+ private void refreshRM() {
+ long now = System.currentTimeMillis();
+ if (lastUpdateTime + recheckDelayMs >= now) {
--- End diff --
This particular bit of code (which I modified to be consistent with the
other refresh case) is designed to avoid banging on the options for every
query. If the system gets 100 queries per second, we don't need to keep
rechecking the options for every query. A small latency is fine and reduces
unnecessary options checks.
---
