io.trino.execution.executor.dedicated.ConcurrencyController Maven / Gradle / Ivy
/*
* 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.
*/
package io.trino.execution.executor.dedicated;
import static com.google.common.base.Preconditions.checkArgument;
class ConcurrencyController
{
private static final double TARGET_UTILIZATION = 0.5;
private int targetConcurrency;
public ConcurrencyController(int initialConcurrency)
{
checkArgument(initialConcurrency > 0, "initial concurrency must be positive");
this.targetConcurrency = initialConcurrency;
}
public void update(double utilization, int currentConcurrency)
{
if (utilization > TARGET_UTILIZATION && targetConcurrency > 1) {
targetConcurrency--;
}
else if (utilization < TARGET_UTILIZATION && currentConcurrency >= targetConcurrency) {
targetConcurrency++;
}
}
public int targetConcurrency()
{
return targetConcurrency;
}
}